LS Swaps A guide worth reading
Found online while reading some FAQ’s on the HP Tuners forum
[learn_more caption=”Engine Modes”] Engine Modes There is a bit of confusion over the different modes the computer can enter so im going to try and clear this up for everyone.
- MAF Closed Loop-MAF is Active, Main fueling O2 sensors are Active Most Stock LS1’s run in this mode corrections are made by the MAF, VE table & O2 sensors at part throttle & from 4000 rpms the MAF takes control of fueling based on your PE, OLFA, COT & any associated adder tables
- MAF Open Loop-MAF is Active, Main fueling O2 sensors are Inactive or removed Many use this mode when the o2 sensors cannot be trusted for whatever reason ie Big cam, LT’s, etc.
- Speed Density Closed Loop-Maf is inactive, removed or Failed, Main fueling O2 sensors are Active Many revert to this mode after doing VE tuning in SDOL mode so the computer can make some corrections for fueling Unless using an HPTuners Custom Operating system you will be stuck in the Low Octane Table Unless using an HPTuners Custom Operating system you will be stuck in the Secondary VE Table(where applicable)
- Speed Density Open Loop(OLSD or SDOL)-Maf is inactive, removed or Failed, Main fueling O2 sensors are Inactive Most will say this is best for VE tuning because you have complete control over what the engine wants to do. Setup your OLFA tables as you’d like to drive around town Setup your PE tables as you’d like to drive around town Just remember the computer will always command whatever table is richest so keep an eye on any adder/multiplyer tables that may be in effect such as Cat Over Temp. Unless using an HPTuners Custom Operating system you will be stuck in the Low Octane Table Unless using an HPTuners Custom Operating system you will be stuck in the Secondary VE Table(where applicable) Bottom Line is to remember Is Speed Density mode doesnt dictate if your in Open Loop or Closed Loop. [/learn_more]
The usual example: MAF tuning vs. SD tuning.
MAF tuning is not a _pure_ MAF tuning. During sudden changes in throttle input, or any other MAP jumps, the PCM prefers to refer to the VE table for airflow lookup/calculation. If you’re not sure how VE table express airflow can, I highly recommend reading my ‘How Speed Density Works’ paper. If this was a “pure” MAF system, ALL requests would come from the MAF and MAF alone.
GM decided to make it into a hybrid system. Why would they do that, might you ask? MAF can deliver very precise, low noise signals, providing simple devices that can be easily calibratable to different applications, and have a reasonable range and resolution. But it also has a problem with not having the cleanest signal when not much airflow is going through the MAF sensor, or failing to deliver a smooth, universal airflow. Speed Density calculations however are just that–math. It’s not dependent on physical conditions, thus not affected by the non-uniform airflow at lower MAF frequencies. As long as all the necessary sensors (RPM, IAT, MAP) are healthy, and all the lookup values (VE, displacement, IFR) are correct, the airflow numbers are going to calculated correctly, despite physical conditions like low, or reverse airflow. The PCM itself is very much airflow source agnostic and it uses whichever source is better suited, or at least yields less erroneous values. Another neat side-effect of having both Speed Density and MAF working together side by side, that if you detect MAF failure (DTC codes P0102 or P0103), the computer seamlessly falls back onto then pure Speed Density mode, so you can safely drive it to the mechanic.
So to all the MAF pundits: you can complain about SD all you want, but the truth is, you’re running in SD at least part of the time you run your car, as there is no such thing as ‘pure’ MAF move on our PCMs.
Some smart guys saw it as strength, an advantage to this dual-source approach, and SD tuning became a reality. Turn off MAF, run in pure SD, and dial in your VE, so it precisely describes the breathing capability of your setup. What do we do with MAF then? After 4000rpm it’s going to take over completely, and we’re going to be ignoring our new perfect VE! That’s when I figured out how to ‘map’ the airflow calculated from the VE table onto the MAF frequency-based scale. This way we have brought back the dual-mode capability to the system, just like the system is designed to work, but now it has new data, tailored to our application. Because of that single source of airflow data, if the PCM decides to jump from MAF to VE based airflow, the airflow numbers should be smooth fit, not causing wrong air mass readings (that’s used to look up timing advance, which in effect can cause bucking), or airflow, which in effects causes knock, or at least hesitation, making for a terrible drivability.
An alternative, interesting approach was to use AFR%Error to manipulate MAF airflow numbers, to establish the new MAF calibration. While theoretically it should yield an identical result as it would with my Dynamic Airflow onto MAF frequency mapping, the reality is too fuzzy, and often yields discrepancies significant enough to cause the engine to get different numbers than it should have. While I do not recommend this method for MAF tuning, I _highly_ recommend using it to verify the VE tune, as well as to observe daily environmentally influenced fluctuations.
Another note to MAF pundits: If you claim that MAF is better purely on basis of not being able to get SD working correctly, you might want to watch out for your ‘MAF’ tune (I put it in quotes because it’s still a hybrid with SD). Every time you get on the gas more vigorously, your untuned VE table will rear its ugly head, and give you an AFR spike, bucking, knock that’s hard to reproduce, hesitation on takeoff and general unpleasantry. There is no escape from doing VE on these systems. Even the most hard-headed MAF tweakers out there have given up, and modify at least the idle areas of VE as without that, making the car idle is somewhere between difficult and impossible.
To farther prove my point about the MAF having very different characteristics on low vs. high airflow situations, let me demonstrate a typical spread of samples from < 5000Hz, and above 6000Hz.
Open Loop vs Closed loop tuning is another huge source of misunderstanding. Partially because it’s just few terms out of a huge body of Control Theory (PID also comes from the same area), without understanding the rest of the principles and theory behind it. Another reason is because of how people use it, it’s almost always referred to as ‘OLSD’, as if it was one thing, which it is not.
Open Loop and Closed Loop are just a methods of control of fueling. OL is basically a system with no feedback. Think of a sprinkler system that sprays the lawn whether it needs it or not. To contrast that, you have CL–a system which takes the output if its own operation as in input for the next round of calculations. In practical terms, it would be a sprinkler system with a ground wetness sensor, and only activating the sprinkler system if the ground is dry. The good part is not wasting water when the lawn doesn’t need any more. The bad part is that we actually need sensors, threshold levels, hysteresis models, and other scientific junk, just to keep the damn lawn from drying out. This is definitely a place to consider effort vs benefit.
So what does it mean for a car? The main benefit of OL control is the direct relationship between what you tell it to do and what it does. It will do exactly what you tell it to, which is good if you tell it the right thing, and potentially catastrophic if you don’t. That’s why most tuning is done in OL–you want to see exactly how much airflow (MAF or VE) and which commanded AFR (OLFA or PE table) yields a particular AFR. This is the entire logic behind tuning–once commanded and resulting PE agree 100%, you can back calculate the airflow from displacement, pulse widths, injector flow rate, RPM, MAP, IAT and AFR. This is how you obtain airflow characteristics of an engine, no matter if it’s with MAF or SD approaches.
Once you obtained that airflow characteristic, you could continue running in OL, and all the environmental changes would show up as change in airflow numbers. In SD, VE table is calibrated in what I call GMVE units, which take temperature and barometric pressure into account. This means that if that pressure or temperature changes, it is easily recalculated to current conditions. In MAF mode it’s even simpler, more airmass cools the hot element of the MAF sensor better, automatically giving you a new, adjusted reading. Both models work just in any condition. (this is an answer to all the ‘do I have to retune for weather?’ questions that show up at least 3-4 times a week on forums)
So if it works so well, then why would we ever need CL one might ask? Doing math for all these models is great, everything agrees, but in practice, things like airflow measurement, or air fuel ratio measurement are an inherently difficult problem. Tuners drive around and scan and know what to adjust when. Normal people dont do that, they hop in and just want it to work, without scanning, analysis, and reflashing their car’s computer. Thus, CL became that automatic tuner. It looks at data from different sensors, and if it consistently points at a new better setting, it adjusts. It’s a perpetual feedback loop, not so commonly refered to as the Closed Loop. This model of course has its limits. While it will adjust to things like weather changes, or driving through the Rockies, it will not adjust for racing camshafts, huge heads, changes of displacement, and other significant changes to the airflow. Car’s computer is willing to adjust, but also must be able to detect hardware failures. To a computer, airflow reading way out of its usual range is flagged as an abnormal event that should be looked at, while to a human it just might mean we put some heads on it. Computer has no way of knowing which one it is, we must tell it.
If you read and understood the last two paragraphs, you might have noticed, that a human tuner, and CL mechanisms (fuel trims) have the same function: to observe and adjust airflow changes. If you think about it, what we usually call the OL tuning method, is really CL–except that the mechanisms doing the adjustments are not automatic and computerized, but human, and done outside of the system.
This brings me to conclusions: in part 1 of this writeup we learned that MAF mode doesn’t really work off MAF alone, and now we learned that Open Loop is a human powered Closed Loop.
I think what happened here is that we got lost somewhere between lack of technical understanding, and the traditional American tendency to polarize and zealotize (is this even a word?) concepts. This isn’t your usual Coke vs Pepsi, Chevy vs Ford, Republicans vs Democrats war of ideologies. Reality is complex, and simple models are just too simple to describe it. That’s why when we want a flexible system we end up doing hybrids, as there usually is no ‘one size fits all’ solution.
So the lesson from this is to learn, explore, and never be afraid to look at an alternative solution, as in more cases than not, you’ll both be right and wrong at the same time, just for different set of parameters. There are very few absolute rights and wrongs, but if you are comfortable with all the alternatives, then at least you have a good chance of picking the best solution for your application, your purpose, your environment. If you’re a tuner that always wants to run on the rugged edge and get as close as possible to 100% of potential, you probably want OL-SD. For a daily driver that doesn’t get scanned too often, CL-MAF or CL-SD are the way to go. If you’re bracket racer and you want as much consistency and control as possible, OL-MAF will probably yield you the desired effect.
Don’t be a close minded zealot–just because a buddy with a fast ride told you something, doesn’t mean it’s going to work for you.
Best bargain sound deadener/ heat shield
Blog is a combination of several posts on 67-72 Chevy Truck forum
If you want to decrease sound you need to go with CCF and MLV. Those stick products are to decrease resonance not block sound.
Here is a great thread on it: http://67-72chevytrucks.com/vboard/s…d.php?t=559596
and another post about it: http://67-72chevytrucks.com/vboard/s…5&postcount=54
Here is a good website that explains it all: https://www.sounddeadenershowdown.co…-vehicle-quiet
You can get it all online. The issue is that MLV is heavy. You can get different pounds per square foot but the shipping is what kills you. If you can find it locally you are golden.
Its kinda hard to work the MLV in tighter spots and depending on what you have close to the floor you might have some clearance issues (gas peddle). Ideally you would want it completely connected. I have used it on other people cars and it makes a huge difference.
I used the advice from sounddeadener showdown and I used Noico on my floors for the vibration dampener & ccf
For the mlv I used this product from Home Depot
In terms of sound damping this is some of the best stuff. And a good price. http://store.secondskinaudio.com/b-stock/
W.R. Grace Ice and Water shield. Home depot online.
Lay the fatmat for sound and rattle insulation. Then use a foam with a foil to reflect heat. I have foam from a generator enclosure on a yacht, it is 1″ thick, with lead shielding, and thick reflective foil. Floor stays cold.
Here’s a quick link I found.
Here’s a source that is mentioned on corvetteforum.com, but I have not compared prices:
From various posts, websites, and experiences
Door vent window
1. Lower the window all the way
2. remove the door trim panel
3. remove the door lock knob
4. remove the screws which attach the vent window lower
assembly to the door panel
5. loosen the inner and outer panel screws which are accessible
through the hole to the rear of the lower vent pivot
6. slide the main glass to the rear, away from the vent window
7. turn the complete assembly 90 degrees and guide it up and
out of the door
8. installation is the reverse of the removal
Door window glass and regulator
1. lower the glass completely, remove the window regulator
handle and the door lock knob
2. remove the door armrest and trim panel
3. remove the door vent window (above)
4. slide the main window glass forward until the front roller
is in alignment with the notch in the sash channel. Disengage
5. push the window forward and tilt the front edge up until the
rear roller is disengaged
6. return the window glass to the level position and withdraw it
from the door
7. if necessary, remove the mounting screws and withdraw the
regulator assembly through the lower opening in the door
8. prior to installation lube the regulator mechanism with chassis
9. installation is the reverse of removal
Raised Bed Floor
another no limit one
UHMW for tailgate trunions
Since I have had allot of people ask me “Whats that blue stuff” on other builds I thought I would show a quick 5 step answer. It is called bluing die or layout die and it is used for many different things. I use it for two main things, one being panel layout. It sprays on and when you use a scribe or just any sharp point it comes off leaving a very visible line to follow. Then I also use it for getting panels as striate as I can when doing body work or metal finishing. Let me be the first to say I am not that great at metal finishing but everything I practice I get a very small amount better. So after welding the seam and working it with a hammer and dolly every step of the way I feel it is almost done but needs a little touch up here and there. So I spray the die on the panel and let it dry for about 10 mins then go over it with a body file to show thew highs and lows.
Then I use the hammer and dolly on the real lows and some on the real highs then I hit it with a long board with 40grit. After that I hammer and dolly more on the low spots and hit again with the long board. I keep repeating this process until I am happy with the results. In this case I would say my lows are only about a 1/6″ to 3/32″ in the bad spots so I will leave it here and finish it off with lead later this week after I get the other side in the same shape.
In these pics the very front and back of the seam are not complete but it gives you the idea anyways.
Paint and Body FAQ List
FAQ part 5 – paint and body
Here’s how I shoot base/clear. (from the interweb)
Lay your stuff out/hang it up, leaving plenty of room to walk around, this ain’t primer, we don’t want any dings here. Blow it all off, and wet the floor. Open a tack rag and spread it open and hang it up to dry out a bit. Crack a beer. Seriously. Put on your gloves.(you got some surgical gloves at the parts house, right? You WANT gloves.) Sip it while you wipe down with a brand compatible wax and grease remover. Strain your materials into the gun. (Ask for Sticks and strainers at the paint store, they’re usually complimentary.) Wax and grease again, then tack down. Half the beer should be gone. Shoot your first coat of base. WALK AWAY (completely out of the shop) AND DRINK THE REST OF THE BEER, at the normal redneck rate, about 5-10 min. Come back in and look over your stuff. You should have a fairly good covering medium coat on. Check your edges, look for runs and dirt. If you have runs or big dirt, wet sand them out now with 600 and wipe down just the affected area lightly (lightly!) with wax and grease and tack off. Then tack the whole thing. Most small dirt and dust will go with the tack rag. Ok, if all is well, shoot your second coat, being real careful to get good coverage, and get your edges covered. Mind your edges and be sure to go all the way, ALL the way to the bottom of the body. Walk away and drink another half beer. Re-inspect. If all is well, Mix clear. If not, wet sand it out, clean up and re-base that part. When you’re finally good, Load up clear gun. Tack off whole job and shoot. Now, on the first round, you just want a light to medium coat, a tack or scratch coat if you will. Very liberally get your edges. Walk away and drink half a beer. Come back and inspect. Bugs and big dirt can be snagged out with the sticky side of some masking tape, just barely touch the thing you want without touching the part. Runs can be handled the same way. Lay some 1/2 inch tape directly over the center of the run and set it lightly down on it (kiss it) and pop it right back off. Note:This only works when the clear is very wet and freshly shot. No touchie otherwise! If all is well, shoot coat two. Go for a nice, uniform coat this time. Mind your edges and be sure to go all the way, ALL the way to the bottom of the body. Walk away and drink half a beer, slowly. Come back and inspect. No touchie from here on in. Shoot coat # 3. Drink the rest of the sixer while cleaning guns and toasting you success. Enjoy your shiny paint job!
101 Paint and Body ideas and tips
Because we know it can be hard to find enough good information buried in a short, four-page tech story, we decided to cut through the flowery descriptions and long-winded explanations and compile this list of 101 paint and body tips. Some of the tips are common sense items that are easily overlooked, and some tips might make you say, “Hey, that’s a great idea.” To keep in line with this article’s structure, we’ll also keep this introduction short. So just read on already.
1. Performing an Internet picture search will give you the fastest results, but it might be hard to find any specific details about paint materials and techniques used on the specific paintjob you’re looking at.
2. Watch movies, because you never know where inspiration will come from. Look at that-we just made watching television educational again.
3. Hot Wheels are not just for collecting, they can be a great source for painting inspiration. Plus, you get to keep the toy.
4.Of course, car and truck magazines are a great place to look for designs and styles.
5. Go to a new-car dealer lot and look at the new cars. OEM paint colors have become pretty cool of late, and this is a good place to see colors on sheetmetal in the sun.
6. Rummage through your old car show pictures. Trends recycle over time and you never know, that booger graphic may come back in style in another decade.
7. Go to a truck show. This will be the best place to find vehicles like yours and see how things look.
8. Check out your local cruise night. You’ll be able to closely inspect the paint and find out who sprayed it.
9. Go to an automotive swap meet because there should be a selection of custom vehicles for sale and the owners are usually standing right there. You might even find a deal on sandpaper while you’re there.
10. Visit custom fabrication and body shops to get ideas from other rides being worked on. It’s not stealing, and imitation is the best form of flattery.
11. Tape out graphic designs on your truck in the driveway. Tape is cheap and it won’t damage your paint.
12. Don’t go too wild with your first paintjob. The loftier the plans, the bigger your wallet needs to be. Besides, you might want to change the paint scheme later on.
13. Have the neighbor kids draw pictures of your truck so you can see what other people think it should look like.
14. Have a rendering made. Get your ducks in a row before you contact an artist though. At least have a general plan and color choices in mind before you bug an artist for a rendering.
15. If you can track them down, talk to other truck owners about their experiences with a shop you want to use. If the shop is reputable, they’ll put you in contact with clients they’ve made happy in the past.
16. Talk about the body mods you want during the estimate. Be specific and don’t forget to mention any work you want the shop to perform. Nothing sucks worse than having your final bill jump up substantially from the estimate because halfway through the job you added more work and forgot about the added cost.
17. Trace/draw your own rendering. Take a picture of your truck and print the picture. Then trace it with a felt tip pen that will bleed through the paper. Flip it over and you will have a coloring book type outline of your truck that you can make a bunch of copies of. Now you can go wild. Heck, you can even give some blank drawings to friends and see what they come up with.
18. If you are going to do the body mods yourself, then talk to the painter and find out what materials he uses. This will cut down on the chance the paint will have an ill reaction like wrinkling if you use the wrong prep products.
19. Don’t decide on a shop until you do some shopping. Get several quotes then pick the one that best suits your needs.
20. Look at the shop’s brag books to see the quality of work and style.
21. Look inside the shop to see how clean and organized it is. Some dirt is fine, but piles of trash and a foot-thick layer of sanding dust isn’t.
22.Check out the booth, prep, and bodywork areas as well. If the booth is really dirty, then there is a chance this shop relies on color-sanding to get the dirt out of the paintjob, and they will be charging you for that.
23. Go back several times. Are the same trucks still there being worked on? This is a sign that the shop might take a long time to finish your work. Also never put down more than a 20-percent deposit to cover materials for your paintjob. This will avoid you getting burned if the shop goes out of business and doesn’t finish the work.
24. Pick your wheel color at the same time you pick your graphics or color. Be sure you can get the wheels you want in the color that works for your truck.
25. When picking a color, put all of the options out on the table and see which one looks the best in the sea of sameness. Example: When Calin was picking the yellow paint for his S-10, he pulled every yellow out of the color books to see which looked the most like yellow in the group.
26. If you’re going to drive your truck every day, it’s best to avoid complicated or detailed graphic jobs that go near the front of the hood. These will be hard to touch up or repair once the rock chips start to show up.
27. If you plan on having your frame powdercoated to match your exterior color, it’s a good idea to pick the powder color first. It’s easier to match the paint to the powder.
28. Get everything you need at once. Some paint supply houses will give you a discount when you make a larger order, and mixing paint afterward if you run out can sometimes lead to mismatched colors.
29. Keep in mind that changing the color of the truck will almost double the price over just reshooting the original color. If you still want to spend all that money and like the original color, then apply the saved money for graphics.
30. Another cool but cheaper option is have the truck two-toned. That way the painter isn’t using as much material or spending as much time to complete the job. As we all know, materials and time equal money.
Prep It For A Shop
31. Unless you’re rich, take the truck apart yourself. Disassemble the truck as much as you can to aid the shop and prevent any of your parts getting damaged or lost.
32. Put old wheels/tires on your truck so your new ones don’t get wrecked while at the body shop.
33. Remove audio equipment or anything of value from inside the cab. Temptation is a powerful thing.
34. Remove the glass. Some windshield and rear side glass is glued in and will need to be cut out. You can do it if you take your time or just have a mobile glass guy come out and do it for you.
35. Make sure your air suspension is easy to operate. Nothing pisses off a shop as much as a truck that leaks and has to constantly be worked on in ordered to be moved around the shop.
36. Make sure the tires hold air as well. The shop may not notice the flat tire and drive on it, and then you get into a pissing match about who’s going to replace it.
37. Clean the truck as much as you can in areas the shop might miss like inside fenderwells.
38. Charge your battery. The truck will be started and moved quite a bit, but not driven long enough for the alternator to recharge the battery.
39. When block-sanding, if you can’t find a block that fits well into an odd body line you can make one from a piece of wood or just about anything you have in the shop. Don’t be afraid to think outside the block.
40.When smoothing plastic for painting, don’t try and sand the plastic smooth with the sandpaper. Just do a light scuff and then put down a few layers of high-build primer and sand that smooth.
41. Another plastic prep tip is to make sure to use an adhesion promoter like Bulldog. The chemicals in these types of products will give your primer more bite and prevent the paint from peeling off the plastic part later on.
42.When shaving a door handle, it will help to get a junk door from the salvage yard so you can cut filler pieces from it. The steel will be the same thickness and have all of the proper body lines and curves. You can also get a completely different door handle and graft that in as well.
43. Line up all of the sheetmetal before you start bodyworking the truck. You don’t want to do a bunch of bodywork and then find out later that your perfectly smooth panels are going to be re-aligned after the parts are painted and re-installed, thus screwing up those perfect jambs and body lines.
44. You can drill small pilot holes where sheetmetal bolts together to make lining up during reassembly a snap. When you reinstall the part, all you need to do is use an awl or a piece of sturdy wire to push in the hole to set the proper alignment.
45. Tape all shims together when you remove them, and also mark where they came from to aid in reassembly.
46. Hopefully you have all of the glass out before you start bodyworking to prevent scratching the surface of your windows with the paper or burning it with the welder. If the glass is going to stay in the truck, make sure to double- or triple-mask the edges and cover large areas with a welding blanket or cardboard.
47. If the glass is out, mask the window opening shut. This will cut down on the amount of sanding dust entering the interior.
48.When MIG welding a small hole closed, you can use a piece of brass to back up the hole instead of using a patch panel. The weld won’t stick to the brass and this is much easier than cutting a small filler piece.
49. For shaving larger holes, make a small patch piece and weld a small tab on it. This will give you a small handle so you have something to hold onto while you do the first tack-welds.
50. When replacing pieces of sheetmetal like rocker panels, make sure to have the door in place and properly adjusted before welding the rocker panel in place.
51. Use glazing putty to fill small pin holes and light gouges for quicker results.
52.If you strip anything down to bare metal don’t let it sit outside. Rust can start showing up in one evening because of the moisture that’s present in the air. You are better off covering the metal with spray paint or duct tape and removing that when you are ready to work the area again.
53. If you use a chemical stripper to remove old paint, make sure to rinse the part and surrounding areas thoroughly before painting. That stuff can linger and hide in tight spaces and could come back to ruin all of your fresh paint.
54. Another bad thing to let sit out in the sun is masking tape. If you have to push your project outside for any substantial amount of time, you are better off removing the tape before the glue dries out and the tape becomes brittle thanks to Mr. Sun.
55. To get the best coverage out of your paint, you can tint the primer to a similar color. Primer is cheaper than paint, so cover as much area as you can with color-tinted primer first before painting if you are looking to save dough.
56. Speaking of cheap, if you’re building a mild custom look into using single-stage enamel paint instead of two-stage. It’s much cheaper than the cost of a two-stage basecoat/clearcoat product.
57. Use 36-grit paper to strip a panel to bare metal, 80-grit to knock down body filler, 180-grit to block primer, and wet-sand the primer with 400-grit before spraying the sealer.
58. An often overlooked area to detail is the small lip on the wheelwell openings. Make sure you get in there and sand it as well so the paint will adhere to it.
59. When you are finished spraying primer, make sure to clean the gun right then and there. The longer it sits, the more chance the primer will dry up in the small passages and turn a quick clean up into a scrubbing nightmare.
60. Read all of the instructions that come with your materials! Even if you have used a product before, you never know if the company made a small change in the formula that will require a different procedure for applying it.
61. Make sure all components are compatible. If you don’t know, don’t mix them. Call your supplier and make sure your sealer, primer and paint won’t react in a negative way.
62. Buy a wall thermometer and humidity gauge (hygrometer) because this will help you mix the paints properly to your booth temperature.
63. Also make sure the truck itself is at the same temp as the booth. If it has been sitting in the cold shop and you pull it in a heated booth you have to let the sheetmetal come up to temp before spraying.
64. Get a water trap in your air line. Nothing will screw up a paintjob faster than a bunch of water entering the gun from the air line.
65. If you are having a custom color mixed, it might be a good idea to get an extra quart added to the order just in case you need to touch up something later.
66. Spray all of the jambs first, then proceed with the outside of the truck. This will cut down on the chance of putting fingerprints in the fresh paint when you go to close the door.
67.You can’t be too clean before painting. Just when you think it’s clean enough, make one more cleaning pass before picking up your spray gun.
68. On your final coat of paint, go ahead and over-reduce the paint by one more part. This will help it lay flatter, but make sure to turn down the air just a bit.
69. A good way to spray flake is to use a gun with a 2.0 tip. The large tip allows the flake to come out without clogging. Add the flake to some clear, drop a small, brand-new nut in the paint-gun reservoir to act as an agitator, crank up your air psi, and spray away.
70. When spraying metallics on a disassembled truck, make sure all of the panels are orientated as if they were on the truck. That way, the metallic paint will lay down uniformly. This can also be applied to flakes.
71. If you are using huge or splinter flake then you will need a flake-buster gun. Follow the instructions on the flake-buster, and once applied, slip-on a nonpowdered rubber glove to gently push the flake down flat.
72. If you have never sprayed candies then don’t try it on your ride with your first paintjob. If you are going to try and spray candy paints for the first time, then cut the candy mixture a little more with an intercoat clear. This will help prevent blotches, but you’ll have to lay down more coats.
73. When spraying the candy, make sure to start at one end of the truck and walk the whole side as opposed to doing it in panels. This will help keep the coats uniform down the whole side of the truck.
74. When you are spraying clear, make sure your first coat is a very light coat. Let it flash off and then you can start laying on thicker coats from there.
75. If you are spraying clear over graphics that have tape lines like stripes, spray a light coat over the graphics first. Let it flash or dry, and then do another light coat over the entire truck. This will reduce the chance of creating runs along the tape lines where clear will build up the fastest.
76. If you do end up with a run or sag in the clear, just let it dry and sand it off later. Some seasoned painters can keep spraying until the run drips off the bottom of the truck but that is a skill learned in time.
77. Ground the truck. A piece of chain that drapes over the truck’s frame and down to the shop floor will cut down on the static charge the vehicle has and reduce the chance of dirt being drawn to it.
78. Don’t lay out any graphics until the truck is assembled and all of the sheetmetal is properly aligned.
79. For graphic lines that carry over a seam like a doorjamb, be sure to carry the line in at least 1/4 inch and then cap it with tape. This will look much better than a bunch of multicolor overspray blobs.
80. To go one step further, you could carry the graphic all of the way through the jambs. But, if you chose to do that, don’t forget the back of the cab and the tailgate jamb.
81.If you are going to use an airbrush to create a design, keep a watchful eye on the tip. It can get partially clogged pretty quickly and screw up the atomization of the air and paint. A quick wipe with your finger tips should be sufficient to remove anything that might be on there.
82.You can save a little money in the pinstriping area by painting it yourself. Instead of learning how to use the brush, add the stripe during the graphics with one more taping step. After you get the graphic laid out, spray your pinstripe color along the edges of the design. Once dry, tape over it with 1/4-inch tape and proceed to paint the graphics color. When everything is dry you can peel away the tape to reveal the pinstriped graphic.
83. To duplicate a design on the other side of the vehicle make a pounce pattern. Use some masking paper to lie over your taped area and rub it with a crayon. The crayon will leave a dark line where it goes over the tape. Remove the paper and set it on a piece of cardboard. Then, with a pounce wheel (small spur-looking thing) punch holes along the dark lines. Place the pattern on the other side of the truck and pat the dotted line left by the pounce wheel with a sock filled with baby powder. You’ll end up with a dotted line of powder to follow with your tape.
84. When the paint/clear is dry use wet or dry paper to knock down the orange peel. 1,500-grit paper is fine for the initial cut, but then switch to 2,000-grit for the final sand.
85. If you are sanding a factory paintjob, grab some 3,000-grit paper and be very careful.
86. Soak all of your wet or dry paper in a bucket of clean water overnight to soften the papers’ backing. This will cut down on the chance the paper will gouge the surface of the body panels.
87. Have a bucket of water and a spray bottle ready when color-sanding. The bucket will be used to clean your paper, and the spray bottle filled with soap and water mixture will be used to lubricate the sanding process.
88. If you are color-sanding a truck that is already assembled, protect all of your chrome and trim pieces with tape to prevent scratching.
89. Use tape to protect body lines and seams. These areas will sand very fast and usually are the first places you will break through.
90. When choosing a buffer, make sure you find one with a variable speed adjustment, like the Dewalt 849 or the Makita 9227CY.
91. Don’t sand an area that you can’t get the buffer into unless you feel like polishing that area by hand.
92.Sand in a back-and-forth motion from the front to the back of the panel, not in circles. Check your progress often with a squeegee. Stop sanding when the surface is devoid of shiny dots.
93. The buffer is designed to be used flat, so fight the urge to tip the buffer on edge. This will just increase the chance of putting in swirls and/or burning the paint.
94. Keep a close eye on your fresh paint if it gets bird poop on it. Remove it quickly because the acids in the crap will have a field day on your unprotected finish.
95.Use rags, cardboard, or any other soft material to protect the paint while you rehang things like the doors or bumpers.
96. Don’t apply wax for at least a month to let the paint fully cure. During that time, you can use a quick-detailing product to keep it clean.
97. For a deep clean before you put wax on the truck, wash it with dish soap. This will remove any wax, dirt, or road grime that might have found its way on the paint.
98. Once the paint is cured and you are ready to wax, use a clay bar on the surface of the truck to remove any tiny contaminants stuck to the paint surface. This will prevent you from trapping a bunch of crud under your wax.
99. After clay, take your time and lay down a very good coat of wax.
100. Invest in a good set of microfiber towels. They don’t scratch paint nearly as bad as shop rags and take off wax with less effort.
101. The last tip we can pass on is to be proud of your work no matter how it came out. No one shoots a perfect paintjob the first time. Just make sure not to repeat any mistakes you might have made the first time.
LS Engine Final Assembly Tips
Step-By-Step Final Engine Assembly Procedures
Step 1: Ready to Begin Assembly
The most exciting time of the engine build is now upon you, as all of your shiny new or refurbished parts will come together to make what you’ve been dreaming of: a fresh LS engine!Don’t let the adrenaline get the better of you, though: follow the below steps carefully (and in order) to ensure you don’t make any mistakes.
Step 2: Install Screw-In Engine Block Plugs
Flip the engine block upside down on its stand. Install any and all block plugs of the screw-in type, including oil gallery and coolant plugs. You should have noted where they all came from during disassembly. All of these are safe to reuse if their sealing washers are in good condition, but be sure to use Teflon-based thread sealant on the threads and under the sealing washer (new plugs include sealant on them). Torque this style of plug to 44 ft-lbs, or 30 ft-lbs if one of these plugs is an engine block heater.
Step 3: Install Press-In Engine Block Plugs
Install a new front oil gallery plug into the front driver side of the engine block. Apply medium-strength threadlocker to its circumference, and tap it in place using a flathead punch or similar instrument. Its outer lip should be recessed about 0.01 inch when fully installed. At this time, also install the rear oil gallery plug (a.k.a. barbell restrictor; use of a new one is strongly recommended). This item can simply push into place by hand, and will protrude just slightly when installed properly. Use no sealant on this plug, just make sure its O-ring is intact and lightly lubricated with engine oil.
Step 4: Install Main Bearings
Wipe each bearing shell seating surface in the block or main cap, as well as the back side of each shell, before proceeding. The upper main bearing shells (grooved) must now be installed into the engine block and the lower main bearing shells (solid) into the main caps. Be sure to install the thrust bearing shells into the center block bulkhead (bottom of first photo) and #3 cap. If you established the need to make one or more of these bearing shells undersize or oversize during pre-assembly, ensure each is being installed in its correct location. Each shell has a tab that fits into a recess in the cap or block, preventing backward installation (finger pointing in second photo). Make sure each shell is fully seated with its edges flush with those of the block or main cap—crooked bearings could spell disaster! Also ensure that your main cap locating dowels are in place in the block at this time (only certain engines have these; for example, the LS7).
Step 5: Insert Crankshaft Into Block (Professional Mechanic Tip)
Give the seating surfaces of the block and main caps, as well as the bearings themselves, a final wipe. Lubricate the upper main bearing shells. Do not forget to lubricate the thrust faces of the #3 main bearing! Spread some lube on the crank’s main journals, too. Now, grasping the crankshaft by the snout and rear flange, slowly lower the crank into the block. Use care not to nick any of the crank journals. Just as the crank is about to rest on the bearings, it may get stuck; slight adjustments in angle of the crank will likely be needed to get it to seat, as it will only go in just the right way. If gentle wiggling does not coax the crank to seat, pull the crank slowly upward and start over; excessive jostling will damage the crank journals or bearings. It may help to rotate the crank slightly as you lay it in.
Step 6: Install Main Bearing Caps and Bolts
After lubricating the lower main bearing shells, lay the main bearing caps in place, being sure to install each numbered cap in the correct location. The “wings” at the edges of the caps all face toward the rear of the engine, with the exception of the #5 cap (you can see this in the accompanying cap numbering photo). The caps likely will not seat fully by hand, as remember they are a tight fit between the deep-skirt oil pan rails. Insert the M10 main cap bolts and start them by hand. To guide the caps down, alternate tightening the bolts side-to-side to ease each cap all the way into place (don’t do this on caps that use locating dowels—tap the cap in place with a rubber mallet). The longer, non-studded main bolts go toward the center of each cap, while the studded ones go toward the outside. Only snug these bolts for now, then install the side cap bolts loosely. If you are re-using your old side bolts, apply some RTV sealant under the heads to prevent oil leakage.
(1) Though GM recommends these M10 bolts be installed dry, some engine builders use a small amount of oil on the threads to help prevent any possibility of thread damage during tightening (you can put some under the heads of the bolts, too). This is only permissible because these bolts use the torque-plus-angle method; doing this would destroy a proper reading if relying on a torque spec only!
(2) If not using GM bolts, follow the lubrication instructions provided by the manufacturer.
Step 7: Tighten Inner Main Bearing Cap Bolts (Torque Fasteners)
Torque all M10 inner main bolts (numbered 1-10 in the accompanying diagram), in the sequence shown, to 15 ft-lbs. Before proceeding further, you must use a rubber mallet to hit the crank rearward, then forward, with a rubber mallet. This aligns the thrust bearing surfaces and it is important to note that final thrust of the crank must be in the forward direction! Then use your torque angle gauge to twist these inner main bolts in sequence an additional 80 degrees. (See “Utilizing Fastener Stretch” on page 118 for reasons why this “torque plus angle” methodology is used by GM.)
Step 8: Tighten Outer Main Bearing Cap Bolts and Side Bolts (Torque Fasteners)
Now, torque all M10 outer main bolts (numbered 11-20 in the first picture), in sequence, to 15 ft-lbs. Once this is done, use your torque angle gauge to add an additional 51 degrees of twist to each outer main bolt, again in sequence. With all M10 main bearing bolts now tight, the main cap side bolts can be addressed. Torque each to 18 ft-lbs; there is no required sequence for these bolts save to say that you should tighten one side bolt and then the other before moving to the next cap. There is also no angle to add to the side bolts.
Step 9: Assemble Pistons to Connecting Rods
Unless you are using a press-fit piston pin (in which case your machine shop will already have put together your piston/rod assemblies for you), now is the time to assemble your pistons to your connecting rods. Read “Piston and Connecting Rod Orientation Rules” on page 113 before proceeding. Piston pin retaining clips vary in style; some are c-clips that install with snap ring pliers or similar tools, while others are spiral-type and must be stretched open to ease installation (shown in hand, such a spiral-type lock must then be worked into one side of the piston pin bore by simultaneously rotating and pushing it into its groove). Once you have a clip in one side, lightly lubricate the piston pin as well as the friction surfaces in the piston and rod with clean engine oil. Slide the pin through the bores in the piston and rod until it hits the clip on the far side of the piston. Then install the other clip atop the pin. Make sure these pin retaining clips are fully seated—they’ll normally click when they’re all the way in (a flathead screwdriver comes in handy for this)! Repeat for all pistons and rods, remembering to install any piston “notched” for reluctor ring clearance onto your #8 connecting rod (see Chapter 5)! At this point, we suggest marking the face of each piston with magic marker to correspond with any number previously scribed onto the rod.
Step 10: Determine Piston Ring Clocking
Most piston or piston ring manufacturers will provide specific guidelines as to ring “clocking,” or placement of the end gaps about the piston’s perimeter. If no clocking recommendations have been specified, you should follow the ring clocking diagram shown here during the below steps of piston ring installation (compression rings can easily be repositioned once installed on the piston, while oil rings are a little more tricky to slide against one another). The most important thing to note is that the oil control rails must be placed about 1-inch to either side of the expander end gap. Most modern ring packages don’t require precise clocking other than this, but you should still space the end gaps of the top and 2nd rings approximately 180 degrees apart.
Step 11: Install Oil Ring Support (Performance Tip)
Some high-performance LS pistons with a short compression height have an oil ring groove that intersects the piston pin bore (see the Appendix). Such pistons require installation of an oil ring support, which sits beneath the oil rings and provides the necessary structure in the area of the piston pin. An oil ring support must be installed before any piston rings, and this is most easily done using ring expander pliers. Oil ring supports will often have a dimple (pointing) that must face down in the area of the piston pin bore. This dimple prevents the support from rotating out of place while the engine is running—you do not want the gap in the support entering this area!
Step 12: Install Oil Rings
It is easiest to install rings if your piston is standing upright (so that you have two hands to work with); your rod vise lying flat on the surface of a table works well for this purpose. Beginning with the #1 piston, lightly lubricate the surfaces of all rings with clean engine oil. Install your oil ring expander into the bottom ring groove, which is the wavy-looking ring (it may have a piece of thin wire connecting its ends, like this one). Note that some ends of expanders simply butt together, while others lock in place. Then install one oil ring control rail below the expander and another oil ring rail above the expander. Oil ring control rails are easily installed by hand using a light twist (set one end in and hold it with your thumb), and ring expander pliers are not required. Note that if your piston has a small opening beneath the oil ring groove (near left thumb in second photo), you should move the rail endgaps past this area, i.e., further apart than just the 2:30 and 3:30 positions shown in step 10.
Step 13: Install Compression Rings (Special Tool)
Proceed to lightly lubricate and install your compression rings one at a time, being sure you are using the appropriate compression ring pair for the #1 piston (they should have been marked after ring fitting). Start with the 2nd ring, which sits in the lower of the two compression ring grooves and normally has a duller finish. Be sure to install the correct side facing up: this will be noted on the instructions included with your rings and is normally indicated by a small dot or a beveled/grooved inner or outer edge (which may face either up or down depending on your ring set). Use ring expander pliers to expand the ring just enough so that it slips around the piston; too much can damage the ring. If you do not have ring expander pliers, you can use your thumbs to push the end gap apart. Now install the top ring, again making sure to follow the ring manufacturer’s instructions on any bevel or dot placement. Once in their grooves, the compression rings should stick out a bit; this is normal and will help the rings put tension on the cylinder walls. Repeat steps 11-13 (as applicable) for pistons #2 through #8.
Step 14: Install Crank Turning Tool (Professional Mechanic Tip)
As with pre-assembly, a lot of crankshaft turning is required during final assembly. For this reason, it helps to install your crankshaft turning tool (if you have one) onto the crank snout at this point. Depending on the style of your tool, you may have to install your oil pump drive gear (which may be part of your crank sprocket) onto the crank snout before putting the crank turning tool on—see step 27. Again, if you do not have a crank turning tool, we recommend simply installing your old crank bolt and using a 24mm wrench to turn it.
Step 15: Install Connecting Rod Bearings (Critical Inspection)
If your rod caps are currently installed tightly to your rods, remove them in accordance with “Proper Connecting Rod Cap Removal” on page 96. Start with the piston/rod assembly for cylinder #1 (remember, each is unique!). After ensuring the bearing shells and their seating surfaces on the rods are clean, install the lower connecting rod bearing shell into the rod cap and the upper shell into the top portion of the rod. As with main bearings, each bearing shell will have a tab that will fit into a recess in the rod or cap, and the shells must be fully seated with their edges flush with those of the rod or cap. Also note that rod bearing shells are not always the same, and your rod bearings may have a top and a bottom half. This is especially true when using chamfered rod bearings to match high-performance filleted cranks. If this is the case, check the back of the bearing shells, which are often stamped with a “U” or “L,” indicating upper and lower shells. As a double-check, watch that the chamfer in the edge of such a bearing will face the filleted edge of the crank journal (i.e., the chamfer must face the front of the engine on odd-numbered cylinders and the rear of the engine on even-numbered cylinders). Lubricate the bearing shells with assembly lube.
Step 16: Turn Engine on Stand and Turn Crank to BDC (Professional Mechanic Tip)
Turn the engine on its stand so that the cylinder deck surface is as horizontal as possible. Give the appropriate cylinder wall one final cleaning, and lightly lubricate it with clean engine oil using a lint-free towel or assembly wipe. Then turn the crankshaft so that the rod journal for the cylinder you are working on is at its furthest point below that bore (bottom dead center). This will give the most room to guide the rod onto it. Also lubricate the crank rod journal with assembly lube.
Step 17: Adjust and Prepare Ring Compressor (Special Tool)
No matter what type of ring compressor you are using, lightly lubricate its inside surface with engine oil. If you have a tapered-sleeve ring compressor, set it roughly atop the bore. Adjustable sleeve-style ring compressors need to be adjusted until the cylinder liner can no longer be seen around its inner circumference. (Many machine shops make a slight chamfer in the top of the bores to ease ring installation, and you can see this in the first photo). As for band-style adjustable ring compressors, they should be wrapped snugly (not tightly) around the piston at this time, leaving the piston skirt exposed. Note: Use of band-style “oil filter wrench” compressors that do not lock to a set position is not recommended and can result in ring breakage!
Step 18: Install Piston/Rod Assembly into Ring Compressor
After verifying ring clocking, lightly lubricate the skirt of the correct number piston/rod assembly and insert it into your sleeve-style ring compressor (or simply insert the piston skirt into the bore if using a band-style compressor). Start pushing the piston very lightly downward by hand. Further minor adjustments to adjustable-style ring compressors may be needed so that the piston can slide through it while still holding the rings firmly. When using a sleeve-style compressor, you will probably need to use your fingers and press each compression ring into its groove, to allow it to enter the tapered section of the sleeve (shown in left photo).
Step 19: Avoid Rod Interference Problems (Important!)
Once the piston skirt has entered the top of the bore and all rings are being compressed, look underneath to ensure the connecting rod is roughly centered and not about to contact any part of the crank or block (or another rod, if one has already been installed onto the journal). Shown is a rod hitting a crank counter weight, a common occurrence. Twist the piston as necessary to get the rod at a 90 degree angle to the crank centerline, and you may also need to slide the rod to center it along the piston pin. Failure to correct these problems can destroy the rod or other components!
Step 20: Install Piston into Bore
Hold the ring compressor against the deck surface and begin tapping downward on the top of the piston with the rubber butt end of a hammer. If the piston stops at any point, do not force it! The ring compressor may be improperly adjusted and a ring may be hanging up on the bore lip. Some moderately forceful taps may be needed to get the piston to move, but anything more than this should be a red flag—in which case you’ll need to stop, pull the piston out, and make any necessary adjustments before trying again. Once you are certain the piston is going into the bore properly, reach underneath and begin guiding the end of the rod with one hand while continuing hammer taps with the other (you may remove the ring compressor at this point if you wish).
Step 21: Guide Rod Onto Journal and Install Rod Cap
As the piston moves down, some further slight twisting of the rod may be needed to help guide it past the crankshaft counterweight (and other rod, as applicable). As the rod nears the crank journal, use extreme care, as any part of the rod touching the journal surface could cause a scratch. Hold your hand around the journal with your index finger and thumb, keeping the rod bolt holes centered on either side of the journal (shown, be prepared to get a little lube on your hand). Once the rod is seated onto the journal, install the rod cap (remember to do so in the correct orientation). On aftermarket rods that use locating dowels, it is recommended that you tap the cap in place using a rubber mallet (in lieu of drawing it down with the bolts) to seat the cap. Either way, install and tighten the bolts until snug. Repeat steps 15-21 until you have installed piston/rod assemblies into all cylinders.
Step 22: Tighten Connecting Rod Bolts (Torque Fasteners)
Note: The procedures described in this step apply to engines using GM connecting rods and rod bolts only. If using aftermarket rods or bolts, follow the tightening procedure specified by the manufacturer, and read “Utilizing Fastener Stretch” below for more information. Flip the engine on its stand so that the oil pan rails are facing up. Starting with the #1 connecting rod, turn the crank so that both rod bolts are easy to access (the crank will be substantially more difficult to turn now that pistons and rings have been installed!). Torque each bolt initially to 15 ft-lbs. Then install your torque angle gauge and give each bolt an additional 75 degrees of twist. Mark on or near the bolt so you know you’ve tightened it, then ensure the rod can slide back and forth on the crank journal (if not, the rod bearings may be crooked). Repeat for each connecting rod until you have secured all sixteen rod bolts.
Early-style GM rod bolts must only be twisted 60 degrees (instead of 75). The most foolproof way to determine whether your bolts are of this type is to look at the area between the bolt head and the threads: if the bolt has a thick shank with a series of shallow, vestigial threads starting just below the head, it is an early-style bolt. Later-style bolts all had a narrower shank interrupted by a larger-diameter sleeve somewhere between the bolt head and threads (exact location varied). The photo compares an earlier (left) and later-style (right) bolt removed from a rod, but you can have a look now just by loosening the bolts and pulling them out enough to look at the shank. Early- and later-style bolts should never be mixed on the same rod!
Step 23: Install Crankshaft Position Sensor
Being sure to use some oil on its O-ring (replace if damaged), install the crank sensor into the passenger side rear of the block. Torque its retaining bolt to 18 ft-lbs. Make sure you are using the correct sensor for your engine and computer: black sensors are for 24X reluctor rings, while lighter colored sensors are for 58X rings.
Step 24: Short-Block Final Assembly Complete
The assembly of the short-block (or “bottom end”) is now complete! Take a well-deserved break, but be sure to cover up your engine while you’re gone to prevent contamination from airborne dust, bugs, and other unwelcome substances. Then, move on to the next step.
Step 25: Install Camshaft (Professional Mechanic Tip)
With the engine right-side-up on its stand, lubricate all cam bearings in the block that you can reach. Before continuing, be sure your hands are very clean, as it will be impossible to avoid contact with the camshaft’s journal and lobe surfaces during installation. The front of the camshaft is recognized by its bolt hole(s) and sprocket locating pin. Lubricate the two rearmost cam bearing journals (and the lobes between them) with engine oil, then insert the cam until it can rest these journals on the front two cam bearings in the block. (Please note that there is no need for moly-based “cam break-in lube” on LS camshafts thanks to their rollerized design!) The fact that Gen III/IV small-blocks use five equally-spaced, equally-sized cam bearing journals allows insertion of the cam segment-by-segment like this, meaning you can lube the journals and lobes as you go along, making the process a bit cleaner. When well on its way in (and little remains exposed to grab onto), an LS cam’s hollow construction lends itself nicely to the use of one or more long 3/8-inch extensions inserted into its central bore for added leverage (longer bolt(s) of the appropriate size and thread pitch can also be used, this is the only option for most single-bolt cams). Continue to insert the cam slowly and carefully (lest you mar the lobes or cam bearings), noting that more and more upward pressure will be required as the cam gets deeper into the block. When it is nearly all the way in, you can even insert a long 3/8-inch extension into the rear of the cam to help guide it the last few inches. Once the cam is in, remove the extension(s) or bolt(s), but be careful—the slight backward tilt of most engine stands means the cam may want to slide its way out the back of the block!
Step 26: Install Camshaft Retainer Plate
Lightly lube the built-in gasket at the back of the cam retainer plate (check once more that it’s in good condition). After wiping the corresponding surface on the front of the block, lubricate the thrust surface of the cam (its outside edge, which is inset slightly) and set the cam retainer in place. Use care not to accidentally push on the cam or it will slip backward and fall onto its lobes. Install the four cam retainer bolts and torque to 18 ft-lbs. If your cam retainer bolts are of a TORX-head design, the specification is 11 ft-lbs.
Step 27: Install Crankshaft Key and Sprocket (Special Tool, Professional Mechanic Tip)
Install your crank key into the crankshaft snout’s keyway using a rubber mallet. Be sure that it goes in squarely or it will be difficult to slide the crankshaft sprocket and/or oil pump drive gear over it. You may have installed your timing set’s crank sprocket onto the crank snout during pre-assembly, but if not, do so now. Spray some lubricant such as WD-40 onto the snout to help this process. Some aftermarket sprockets will simply slide over the snout and only require a few light hammer taps to seat fully on the crank. Factory-style sprockets should be started with light hammer hits, but will need to be pressed on the rest of the way using a crank gear installing sleeve (possibly combined with a harmonic balancer installer tool). The alternative to buying a sleeve is to simply use your old crank sprocket (shown)! This method will also require your old crank bolt and is easier and cheaper than buying a special sleeve. Press the sprocket on until it firmly seats against the crank, then remove your old sprocket, it should just come off by hand.
(1) Some cranks (expecially aftermarket ones) use a second key located further outward on the snout (to properly index aftermarket harmonic dampers and prevent any chance of it spinning on the snout). If using such components, install the second key at this time as well.
(2) If using an adjustable timing set, be sure to install the crank sprocket using the correct keyway you determined during pre-assembly.
(3) Do not use hard hammer hits to install the crank sprocket, this can cause severe engine component damage!
Step 28: Install Camshaft Sprocket and Timing Chain
Turn the crankshaft until the alignment mark on its sprocket is at the 12:00 position. Spin the camshaft by hand until the cam locating pin is facing to the right (roughly 3:00), making sure not to push the cam backward at all. This pin placement will help get the cam sprocket locating mark roughly where it needs to be. Lubricate the thrust surface at the back of the cam sprocket and soak the timing chain in oil. Once this is done, take your cam sprocket and hang your timing chain on it. Reach behind the engine with one hand to hold the cam from moving backward (this also allows you to turn the cam slightly if needed). Put the cam sprocket in place while simultaneously wrapping the timing chain around the crank sprocket. You may have to take the cam sprocket and chain on and off of the engine a few times until you get the marks on the cam and crank sprockets to line up vertically (they should be at 6:00 and 12:00, respectively). Start the cam bolt(s) by hand (some aftermarket timing chains afford very little slack, making this difficult); torque to 18-26 ft-lbs (cams with three small retaining bolts) or 66 ft-lbs plus 40 degrees (cams with one large retaining bolt).
(1) Be sure to use the correct sprocket markings determined during pre-assembly if using an aftermarket adjustable timing set.
(2) Engines equipped with VVT have the cam phaser mounted to the front of the cam sprocket, and the assembly is secured to the camshaft by an actuator solenoid valve in lieu of a bolt. It must be tightened to 48 ft-lbs plus 90 degrees.
(3) The timing chain tensioner (on engines so equipped) may need to be installed before the chain and cam sprocket. In this case, the tensioner will need to be temporarily deactivated using a pin or similar instrument while the chain and sprocket are put in place.(4) Engines equipped with a timing chain dampener (which sits in the area between the cam and crank sprockets) should install it at this time, torquing its bolts to 18 ft-lbs.
Step 29: Install Oil Pump
If your crank sprocket does not have the oil pump drive gear built-in, slide this item onto your crank snout now. Wipe the mating surfaces on the front of the block and back of the oil pump, then set the pump in place over the crank snout. You may have to twist the oil pump’s gear teeth so that they align with the teeth on the crank sprocket (or separate oil pump drive gear). No gaskets or other sealants should be used between the pump and block surfaces. Torque spec on these bolts is 18 ft-lbs. Once the oil pump has been installed, flip the engine over on its stand.
(1) If you are using an aftermarket double-roller timing chain, be sure to place any supplied spacers between the pump and block (and use any longer bolts supplied). Most aftermarket oil pumps do not require spacers as they are designed with the thickness of a double-roller chain in mind.
(2) While most pumps self-align properly to the block, LS7 oil pumps must be held flush or no more than 0.04-in. above the oil pan rails at the bottom of the block—no protrusion below the rails is acceptable! A straight edge or the GM J 41480 can be helpful in determining this—this is the same tool used to align the front and rear covers to the block (see steps 33-34). The procedure is similar for the LS9.
Step 30: Oil Deflector Tray Modification (Performance Tip)
Note: this step applies to high-performance applications only. For stock rebuilds, skip to the next step. When using a crankshaft with a larger-than-stock stroke, modifications to your oil deflector tray may be required to obtain adequate rotating clearance. To check for contact between your rotating assembly and the tray, set it loosely in place atop the main bolts and rotate the crank, watching and listening for any interference. Most commonly, this occurs between the tray and the heads of the rod bolts. To correct for this, mark the tray at all points of interference, then take it off of the engine and use a hammer and chisel to bend the tray in these areas. Do not close off any gaps in the tray completely—this will create oil flow problems. Reinstall the tray and ensure you have adequate clearance, noting that some extra space will be necessary to account for crank stretch at high RPM!As an alternative to modifying the oil deflector tray, you may also install a set of aftermarket tray spacers (see “SLP Performance Parts” on page 122), but be aware of the following: because the oil pump pickup tube mounts atop the tray on most engines, some modifications (i.e. slight bending of its bracket) may be required in order to correct for decreased clearance between the pickup tube’s screened inlet and the floor of the oil pan. This is easy to check with clay later during oil pan installation. A final note on oil deflector tray modification is that if you are using aftermarket main studs, they may require some of the holes in the tray to be enlarged slightly, which is easy enough to do with a drill or die grinder.
Step 31: Install Oil Deflector Tray and Pump Pickup Tube
Lay the oil deflector tray atop the main bolts, noting correct orientation (most are marked “REAR” at the back). It is a good idea to shoot some oil into the oil pump inlet at this point for initial lubrication. Install a new O-ring onto the end of the oil pump pickup tube. Coat the O-ring and the oil pump inlet opening with oil, then push the pickup tube into the oil pump. Ensure the tube is all the way in before inserting and tightening the retaining bolt, or else you may damage the O-ring or push it out of position. The retaining bolt gets 106 inch-lbs of torque, while the eight stock deflector tray nuts (one of which also secures the pickup tube bracket) receive 18 ft-lbs. If using aftermarket main studs and tray nuts (as shown here), use the torque specifications provided by the manufacturer.
(1) There are at least two different styles of pickup tube used on LS engines. Some tubes neck down near the end before bumping up to a flange. These tubes require a thicker O-ring, which is normally green in color. Other pickup tubes do not neck down and require a thinner (usually blue or black) O-ring; it is this type that is shown in the photos. An incorrect O-ring can cause loss of oil pressure and severe engine damage, so be sure you are using the correct type!
(2) If your oil pump has been spaced forward for use of an aftermarket double-roller timing chain, slight bending of the pickup tube bracket will be required for proper fitment.
(3) On dry sump engines (such as the LS7), the pickup tube is part of the oil pan, so only the deflector tray is installed at this time.
Step 32: Install Crankshaft Oil Seals into Front/Rear Covers
The crankshaft’s front and rear oil seals should not be reused, and must be removed from the engine covers and discarded. A hammer and flathead screwdriver can be used for this, though care must be taken not to score the aluminum surfaces of the covers. GM recommends waiting until the covers are on the engine to install new seals, but this requires special J-tools (which are invariably expensive or hard to get a hold of). The front seal is fairly easily tapped into place about its edges with a rubber mallet; do this slowly and gently or the seal will be destroyed. While the same can be done with the rear seal, you can also use this tool made by now-defunct Wheel to Wheel Power-train (which tightens to squeeze the seal into place, second photo) to make the job more fail-safe. A thin film of oil applied to the engine cover surfaces will help the seals press into place. However, the seals themselves are designed to be installed dry—do not lubricate their inner rubber surfaces! If you are afraid of botching this step, know that new front and rear covers are available from GMPP with seals pre-installed (see “GM Performance Parts” on page 125 for more information).
step 33: Install Rear Cover (Special Tool Used, Precision Measurement)
Before installing the rear cover, make sure the rear oil gallery plug (barbell restrictor) is still in place at the driver side rear of the block (see step 3)! Set a new gasket in place on the rear cover, using the first couple of threads of each rear cover bolt to hold it there. Wipe off, but do not lubricate, the crankshaft’s rear flange. You must be very careful when sliding the rear cover onto the block, as it is easy for the lips of the rear crank seal to become misaligned while doing this, resulting in an oil leak (updates to GM’s seal design have made this much more foolproof, though). The aforementioned Wheel to Wheel Powertrain tool’s aluminum “donut” helps ease an earlier-style seal’s transition onto the crank. Once all rear cover bolts are started by hand, you have a choice. The first option is to use a GM cover alignment tool (J 41480) to align the rear cover’s cover-to-pan sealing surface with the block’s oil pan rails before torquing the rear cover bolts to 18 ft-lbs. As an alternative, you may visually align the cover-to-pan sealing surface with the pan rails, tighten the bolts, and then verify no more than a 0.020-inch drop between the pan rails and rear cover using a straight edge and feeler gauge (any protrusion of the cover beyond the pan rails is unacceptable). This latter method will usually provide acceptable results since contact between the rear seal and crank flange helps roughly align the cover to the block.
Step 34: Install Front Cover (Special Tool, Precision Measurement)
The front cover goes on next, being sure to use a new gasket behind it. This cover is most easily aligned using the same alignment tool used for the rear cover, along with an additional J 41476 tool to help align the cover side-to-side.(This latter tool was not used in the previous step since the rear seal had already been installed and was basically serving the same purpose). Install the J 41476 hand-tight using your old crank bolt before installing the J 41480. If you do not have access to these two tools, it is strongly recommended that you wait until after you install the harmonic damper (step 59) to tighten the front cover bolts. This will help align the cover side-to-side and will of course require the oil pan to be installed after the harmonic damper as well. Either way, the front cover bolts get 18 ft-lbs of torque, and you must also verify no more than a 0.020-inch drop between the pain rails and the cover-to-pan sealing surface.
(1) Some aftermarket oil pumps require grinding to the inside surfaces of the front cover for proper fitment. Be sure to clean all shavings from the cover and seal after doing this.
(2) The LS7 does not use the J 41476, but rather its own specialized set of cover alignment tools, which require that the front crank seal not be installed until afterward. Absent access to these tools, it is recommended that you take the route of installing the harmonic damper first to help align the LS7’s front cover. The LS9 installation is similar.
(3) Engines equipped with VVT have provisions for actuating the cam phaser mounted to the front cover (you should have noted their layout during disassembly), so be sure to install these components now as well.
Step 35: Prepare to Install Oil Pan
Oil pan design varies substantially by engine and application, however all are installed using the same methodology. First, make sure any and all internal baffles, the oil filter adapter, the oil filter bypass valve, and like items that you may have removed during cleaning are in place and tight. Then set your new pan gasket atop the oil pan, using as many bolts as you can to hold it (it is not necessary to actually rivet the gasket to the pan, though you can if you wish). Now, apply a 1/4-inch bead of RTV silicone at each of the four meeting points of the block and front and rear covers. You will note that the front and rear cover gaskets protrude toward the pan gasket slightly at each of these points, but this RTV is for extra insurance.
Step 36: Install Oil Pan (Precision Measurement)
Now set the oil pan in place on the engine block. Depending on the baffle design of your pan, it may not drop straight down, but rather require some wiggling and/or angling to install. A properly installed pan will sit flush on the engine block; if it does not, your pickup tube may be hung up in the oil pan baffle(s), so lift up and try again. Once you are confident the pan has seated correctly, tighten the bolts only snug and use a straight edge to measure the pan’s location with respect to the rear of the engine block. Because the oil pan forms a structural part of the driveline (heck, even some of the bellhousing bolts attach to it), this dimension is critical: the pan cannot protrude beyond the back of the engine block, and may only be set forward 0.010-inch on most engines. On some engines, a maximum of just 0.004-inch is considered acceptable! After making any necessary adjustments to get the pan location correct, tighten all the short oil pan bolts to 18 ft-lbs. and the two long pan-to-rear-cover bolts to 106 in-lbs (most engines; pan and bolt style may vary). After verifying pan alignment is still acceptable, replace any and all sensors you previously removed from the oil pan (for example, the oil level sensor and oil temperature sensor, these vary by application).
Step 37: Install Camshaft Position Sensor
Turn the engine right-side-up on its stand. On Gen III engines, the cam sensor slides into the top rear of the block, and its retaining bolt is tightened to 18 ft-lbs. On Gen IV engines, the sensor is installed into the front cover, and its bolt gets 106 in-lbs. (the sensor on VVT-equipped engines is similar but not identical). With either style, be sure to use some oil on the O-ring. Many Gen IV engines also have a wiring harness extension and bracket (leading to the bottom of the cover) that you may wish to install now.
Step 38: Install Valve Lifters and Guide Trays
The best way to install the lifters into the engine is to first insert them into the lifter guide tray. Apply some engine oil to the grasping areas of the tray, then slide the lifters in. Because the tray grabs onto the flat areas on either side of the lifter, the lifters will only go in one of two ways, with either being acceptable (orientation of the lifter’s oil hole on the side does not matter). Then spread oil on all surfaces of each lifter—roller tip included—and push the tray into place in the engine. Each lifter should slide easily into its bore. On some engines, the shape of the tray dictates that it can only be installed in one orientation, but on others this does not matter. Tighten the lifter guide’s retaining bolt to 89-106 in-lbs—do not overtighten and crack the tray! Repeat for the other three trays until you have installed all 16 lifters.
(1) It is recommended that you not soak hydraulic lifters in oil before installation, as this can interfere with proper rocker tightening (stock rebuilds) or with valve lash adjustment (high-performance rebuilds using adjustable rocker arms).
(2) On AFM-equipped engines, the lifters for cylinders 1, 4, 6, and 7 look slightly different, mainly in that they have built-in springs that allow them to follow their cam lobe profiles while deactivated. Be sure to install them into their correct locations. The areas that the guide tray grabs onto are also of a different shape on these cylinders.
Step 39: Press in Cylinder Head Locating Dowel Pins
There are two dowel pins for each deck surface of the block, one at the front and one at the rear. It’s best to not reuse your old dowels, so install new ones now. Each must be pressed into its hole as completely as possible, and light hammer taps may be needed to do this.
Step 40: Lay Head Gasket on Block
Wipe the deck surfaces of the block clean one last time before proceeding. Tilt the engine in its stand so that one deck surface is horizontal. Take a head gasket and place it on the block, noting any markings on the gasket such as “FRONT” or “THIS SIDE UP.” Some gaskets are unmarked; to determine their orientation, note that because the rear portion of many LS blocks has more coolant passages between the block and heads, these must match any corresponding holes in the head gasket. Also, you may have to press down on the lower corners of the gasket to seat it onto the dowel pins.
Step 41: Inspect Cylinder Head for Gasket Incompatibility Recess (Critical Inspection)
Some early Gen III heads have a recessed area along the edge of the deck surface, just below the number 3 or 6 exhaust port (the head shown does not have the recess, but it would be exactly in the area pointed at). If your head has a recess, you cannot use GM’s newer-style MLS head gaskets, but must rather use a GM graphite-layered steel core gasket. See Chapter 4 for a comparison photo of these two types of gaskets. In the case of aftermarket gaskets, consult with the manufacturer for head compatibility information. If your heads are not currently assembled, follow “Cylinder Head Assembly” Workbench Tip before proceeding to step 42.
Step 42: Install Cylinder Head and Bolts
Make sure that the deck surface of the head is completely clean. Grasp a head along its sides (holding fingers inside the intake ports works well) and set it in place atop the head gasket. Ensure that it locates properly on the dowel pins. There are fifteen head bolts: ten that are large in diameter (M11 thread on most engines) and five small in diameter (M8 thread). Insert them at this time and turn them until they are just barely snug against the head.
(1) If you have a 2003 or earlier block, two of the M11 bolts are shorter than the rest, and these must be installed at either end of the top row of M11 bolts (locations #9 and #10 in the diagram shown in the next step; there is one shown being inserted in the photo to the left). On 2004 and later blocks, all M11 bolts are of the same length.
(2) While you must always install new M11 bolts, your old M8 bolts can be reused so long as you apply medium-strength threadlocker to the first several threads.
Step 43: Tighten M11 Head Bolts (Torque Fasteners)
Refer to the accompanying image for bolt numbering. The M11 bolts must be tightened in three steps. These bolts require a substantial amount of force to twist, so you may wish to have an assistant help you hold the engine stand from rolling around while you’re doing this!
FIRST STAGE: Using a torque wrench, tighten the M11 bolts numbered 1 through 10 in sequence to 22 ft-lbs.
SECOND STAGE: Now use a torque angle gauge to add 90 degrees of twist to these same bolts, again in sequence.
FINAL STAGE: The specifications to use in this stage depend on the style of head bolts that your block uses.
2004 and later blocks with all-same-length M11 bolts: add an additional 70 degrees of twist to the bolts in sequence.
2003 and earlier blocks with long/short M11 bolts: add an additional 90 degrees of twist to the bolts numbered 1-8 in sequence. Then add 50 degrees of twist to the shorter M11 bolts in locations 9 and 10.
(1) For engines using M12 head bolts (such as the LS9), refer to your GM service manual.
(2) If using aftermarket head bolts or studs, refer to the installation instructions and tightening specifications of the manufacturer. However, the above tightening sequence should always be used.
Step 44: Tighten M8 Head Bolts (Torque Fasteners)
Once all M11 bolts are secured, use a torque wrench to tighten the M8 bolts numbered 11 through 15 in sequence to 22 ft-lbs. There is no angle to add to these bolts. With all head bolts fully tight, repeat steps 40-44 for the other cylinder head.
Step 45: Mask Off Intake Ports (Professional Mechanic Tip)
As the valves are about to become operational, you do not want stray bolts or other items accidentally entering the cylinders, requiring head removal. Avoid any chance of this by masking off the opening of each port—especially those of the intakes—with tape. Once applied, you may want to punch a small hole into each piece so that the engine can “breathe” as rockers are being installed and the crank is turned over (this latter concern doesn’t apply so long as you have not yet installed spark plugs).
Step 46: Install Pushrods
Lubricate the lower tips of all sixteen pushrods with engine oil, then slide each into place through its passage in the cylinder head. Press down on each one as it is inserted to make sure the tip is centered onto the lifter plunger, and also to push the lifter down onto the cam. For the moment, do not lubricate the upper tips of the pushrods.
Step 47: Prepare to Install Rocker Arms (Important!)
On engines using stock or small-duration aftermarket camshafts, it’s possible to install and tighten the rocker arm bolts eight at a time at just two different positions of crankshaft rotation. However, since long-duration cams can cause some lobes to command lift at these positions, we’re going to go through a procedure that will work regardless of camshaft used. First things first, though: thanks to the rollerized design of factory LS rockers, we suggest submersing them in engine oil to help lube the internal bearings. After this, you must lubricate each tip with engine oil and liberally lubricate the pushrod cup (a specialized assembly lubricant is strongly preferred over oil for this area because of the amount of friction that will occur here at startup). Also lube the area that will contact the underside of the rocker bolt head with oil to assist in proper tightening, and use your oiling can to squirt plenty of oil between the valve spring coils onto the valvestems. Then, for cylinder heads where the rocker pivot supports are not a machined part of the head (this is the case with most LS heads), lay the rocker stands in place on each head; some aftermarket stands get bolted in place. Please note: because our method of rocker installation does not involve installing all rockers simultaneously, the factory stands must have at least 2 rocker bolts inserted into each of them at all times (spaced as far apart as possible) in order to prevent the stands from shifting out of place—the built-in factory alignment tabs alone will not stop this from happening!
Step 48: Install Rocker Arms (Professional Mechanic Tip)
Note: this step applies if using stock-style rocker arms only. If using aftermarket adjustable rocker arms, skip to step 49. The rocker installation process will require some attention—along with an assistant—because of the tendency of the lifter guide trays to hold the lifters off of the cam once they are raised, which masks lifter movement. However, when done correctly, the results will be properly tightened rocker mounting bolts on any application! 1. Start off by having your assistant use your old crank bolt to turn the crankshaft clockwise (most crank turning tools can no longer be used thanks to the front cover being in the way). 2. Hold downward tension on the pushrods for cylinder #1. This prevents the lifter guide trays from holding the lifters up artificially. Wait until the exhaust pushrod just begins to move upward (the exhaust is the one on the right when looking from the side of the engine). 3. At this point, lube the pushrod tip and install the intake rocker arm (make sure the pushrod enters its cup on the underside of the rocker properly) and torque its mounting bolt to 22 ft-lbs. 4. Continuing to hold tension on the exhaust pushrod, have your assistant turn the crank until your newly installed intake rocker rotates the intake valve open and then almost completely closed. Now install the exhaust rocker arm, torquing its mounting bolt to the same 22 ft-lbs. 5. Repeat this step for every cylinder until all sixteen rockers have been installed.
(1) Gen IV-style heads use rockers with offset tips for the intake valves. If you have this type of head, remember to install these rockers in the correct locations. (Recall, though, not all Gen IV engines use “Gen IV-style” heads, see our “LS Cylinder Head Evolution” Workbench Tip in Chapter 4 for more information.)
(2) If using an aftermarket cylinder head where the intake rocker mounting bolt intersects the intake port, it is not a bad idea to apply some RTV sealant to its threads.
(3) If you’re getting confused about which lifter is on the base circle of the cam at any given point, it helps to verify by viewing the lifters through the cast-in “gaps” at the front and rear of the valley. See above, picture 6. Unfortunately, this is only possible for cylinders 1, 2, 7, and 8 since these lifters are the only ones visible through these gaps. The alternative is to wait until after rocker installation to install the engine covers; this way, the cam sprocket will be visible during this step to help you sort things out.
Step 49: Installing Aftermarket Adjustable Rocker Systems (Performance Tip)
Note: this step applies to high-performance applications only. For stock rebuilds, skip to the next step. When using aftermarket adjustable rocker arms, the installation procedure is often very similar to that discussed in step 48, and you should always follow the instructions provided by the manufacturer when using such a system. However, here are a few helpful hints to guide you if you’re using a shaft-mount rocker system (this is not the only style of system available for LS engines, but they are by far the best). With installing an adjustable shaft rocker system, the main thing to keep in mind is to back the lash adjusters off all the way (i.e., as high as possible) so that they do not interfere with the process of tightening the mounting bolts. Also when installing and tightening their mounting bolts, since most shaft rockers are joined together as one pair for each cylinder, both lifters must simultaneously be on the base circle of the cam lobes (rotate the crank until a bit after the intake lifter returns to its lowest point). Once a rocker pair is installed, each rocker is then individually adjusted as follows: the lash adjuster is turned until it just contacts the tip of the pushrod (“zero lash”), then a specified number of turns (usually 1.5 to 2) are added to achieve the proper lifter preload. The lash adjuster is then locked in place via a nut.
Step 50: Install Valve Covers
With all rockers installed and adjusted (as applicable), we can button up the top of the cylinder heads with the valve covers. Most LS cylinder heads use four centrally located bolts to hold the valve cover in place. These bolts must be torqued to 106 in-lbs in an inner-to-outer sequence. New valve cover gaskets are mandatory, though the grommets under each of the bolts are OK to reuse.
Step 51: Install Valley Cover or LOMA
Set the valley cover (or LOMA on AFM-equipped engines) atop the block with a new gasket in place. Some aftermarket intake manifolds require substitution of the stock valley cover bolts, as their heads are too tall to afford adequate clearance from the floor of the intake. Either way, torque these bolts to 18 ft-lbs.
Step 52: Install Oil Pressure Sensor
On Gen III engines, install the oil pressure sensor at the upper rear of the block (next to the cam sensor, shown); tighten to 15 ft-lbs. On Gen IV engines, the oil pressure sensor installs into the rear of the valley cover and receives 26 ft-lbs of torque. Be sure to reuse the sealing washer under the sensor (as applicable) and use some Teflon-based sealant on the threads (new sensors normally already have sealant applied).
Step 53: Knock Sensor Installation
If your engine is a Gen III, the knock sensors mount into the top of block, in the valley cover area. Carefully lower each sensor into place and torque to 15 ft-lbs. If your engine is a Gen IV, the knock sensors install low on either side of block (not shown); the retaining bolt of each gets 15-18 ft-lbs.
Step 54: Installing Knock Sensor Wiring Harness
Note: This step applies to Gen III engines only. For Gen IV engines, continue to the next step. Because the intake manifold is about to obstruct access to the top of the valley cover, the piece of wiring harness that connects to the knock sensors on Gen III engines must now be plugged in. Run the wiring to the rear of the engine, and make sure the seals seat properly in the valley cover as well.
Step 55: Install Coolant Air Bleed Pipes
The last items to be installed before the intake manifold are the coolant air bleed pipes (or blockoff caps, if originally equipped at the rear—never install blockoff caps between the fronts of the cylinder heads!). As discussed when they were removed during disassembly, exact style of these pipes varies by engine; however, all are installed with bolts tightened to 106 in-lbs, making sure a gasket or O-ring is used in between.
Step 56: Install Intake Manifold (Torque Fasteners)
Before setting the intake manifold in place, install new intake port seals (car intakes, shown) or clip new carrier-style gaskets (truck intakes) in place. The intake port seals may want to creep out of their grooves, so ensure they are seated correctly before proceeding. Remove the masking tape from your intake ports and wipe the sealing surface of the heads, then place the manifold on the engine. Start its ten bolts by hand (use some threadlocker on their threads). You will need to make sure any brackets that attach to the intake manifold (and were removed during disassembly) are returned to the same place before doing this, as some are held by the intake bolts. Torque the bolts, in the sequence shown, a first pass to 44 in-lbs and a second pass to 89 in-lbs. (Note: For factory-supercharged engines such as the LS9 and LSA, refer to your GM service manual for installation instructions.)
Step 57: Install Fuel Rails, Throttle Body and Intake Manifold Accoutrements
Exact style of fuel rails and injectors varies by application, but they should be installed now using threadlocker on the bolts. Fuel injector O-ring seals should be lightly lubricated with engine oil to ease insertion, and again, if reusing your injectors, use of new seals is mandatory! Throttle bodies are installed via either 3 or 4 bolts, and a new seal should be used for this, too. Now is also a good time to install the MAP sensor, any PCV system hoses, brackets, throttle body sensor(s), and any other items originally removed during disassembly. The detailed notes and photos you took regarding these items will pay off big time here!
Step 58: Install Flywheel or Flexplate (Torque Fasteners, Special Tool)
Line up the “extra” hole in the flywheel or flexplate with that in the back of the crankshaft (if applicable). Apply threadlocker to the threads of the six bolts and install them. Torque to 15 ft-lbs using the sequence shown in the accompanying diagram, then repeat this sequence for additional stages of 37 and, finally, 74 ft-lbs. A flywheel holding tool is suggested for this step, though you can also have an assistant insert a pry bar into the flywheel/flexplate’s teeth (as may have been done during disassembly). Note that some ultra-high-performance engines such as the LSA and LS9 use an 8- or 9-bolt crankshaft flange; in this case, refer to your GM service manual.
Step 59: Install Harmonic Damper (Professional Machanic Tip, Special Tool)
Because of the high bolt torques needed for proper harmonic damper (“balancer”) installation, it is strongly recommended that you now install a flywheel holding tool to keep the crankshaft from turning over. There are two methods that can be used to press an LS damper onto the crank snout. The first involves using a harmonic balancer installation tool, which is fairly self-explanatory (not shown). But back in Chapter 2, we also mentioned that an alternate method is available, and here it is: acquire an M16 x 2.0 x 120mm bolt along with at least a few washers. Use this longer bolt (with the washers underneath to help it spin) to pull the damper onto the crank snout, switching to your old crank bolt if the longer one bottoms out. Watch to ensure the crank seal in the front cover stays intact during this process (do not lubricate the seal or the corresponding surface on the damper). With either method, once the balancer is on the crank as far as it will go, install your old crank bolt and torque to 240 ft-lbs. Remove it and ensure the crank snout is recessed no more than about 0.175-inch from the innermost ridge of the balancer. Only then may you install your new crank bolt, torquing to 37 ft-lbs plus 140 degrees of twist.
(1) Never attempt to press on the damper using just your old crank bolt! You will destroy the first few threads in the crank snout.(2) Some engines use a special locking washer between the front of the crank snout and the balancer (you should have noted this during engine disassembly). Be sure to install it during this step, as applicable.
(3) Because of the different length crank snouts used in some Gen IV engines (for example, LS4 and LS7), a different length bolt may be needed than that listed.
(4) While most factory cranks and dampers are not keyed to one another, many aftermarket ones are. In this case, you will need to align the keyway in the damper with the key in the crank for proper installation.
Step 60: Final Engine Assembly Complete
At this point, final engine assembly is roughly complete. We’ve installed every key engine component, and basically everything that’s left is better considered an accessory! Your stage of desired completion at this time may vary; you’ll need to think back to engine removal and disassembly to decide “how much further to go” while the engine is still on its stand, since further component installations may hinder your ability to easily install the engine into the vehicle and/or onto the vehicle’s removable subframe. Some of the items you may wish to bolt up now, but which we will not go through in detail, include:
- Starter motor
- Engine mount brackets
- Spark plugs
- Ignition coils and brackets
- Water pump
- Other accessory brackets
- Exhaust manifolds (use threadlocker on these bolts)
- Oil filter
- AIR system
- Dipstick tube
- Clutch pilot bearing/bushing
Most of these items are pretty self-explanatory to reinstall: just reverse the steps you went through during disassembly (see the Appendix for some helpful torque specifications). That said, move on to Chapter 9 for hints on installing, tuning, and breaking-in your newly-rebuilt LS!
Written by Chris Werner and Posted with Permission of CarTechBooks