How-To : Piston Install

[Tennpenn83]

I will do my best to explain, but I do not have pictures of EVERYTHING. I will try to explain the step-by-step with some added pictures along the way. I do not have all the socket sizes memorized for the various parts of the motor, but I will assume that if you're going this far into your motor, you can figure out which socket will fit which bolt. Also, STRONGLY recommended to use Zip-Loc baggies marked with a Sharpie to hold various bolts coming off the engine in order to keep track of which bolts go where. Keep in mind that I am not a mechanic - I am an enthusiast who works on my own car. Do NOT take what I say as gospel, and remember that YOU are taking the risk working on YOUR car. These instructions that I am providing are the guidelines that I used, and they worked for me. You may have some different methods. Read the whole write-up before you begin any work on your car. If you do not feel comfortable doing any of the tasks in this write-up, then simply don't do it.

Again, I do not take responsibility for what YOU do to YOUR car.

Two books that are STRONGLY recommended that proved their worth are GM's ECOtec 2.0 LSJ POWER and GM's GM Sport Compact Performance Build Book (part number 88958646 which is available through GM). This first book is also available in an online Adobe version available here.



The LSJ can be fully assembled/disassembled with basic hand tools, 99% of them metric. The items needed specifically for replacing pistons are :

- Aftermarket Pistons (stock, Diamond, Wiseco, etc. in various compression ratios)
- New Piston Rings (stock, Total Seal, etc.)
- Piston Ring Spreader
- Piston Compressor
- Gasket Maker for re-installation of the Oil Pan
- Cometic Headgasket and aftermarket head studs (ARP, etc.) OR Head gasket kit from GM (Part #12595961 - comes with new stock headgasket, new stock head bolts, new intake manifold gasket, and exhaust manifold gasket)
- New Rod Cap bolts (x8 - GM Part #90537293)
- New Cam Gear Bolts (x2 - GM Part #90537451)
- New Crank Pulley Bolt (x1 - GM Part #11589123)
- Recommended but not required are Valve Cover (GM Part #90537687) and Timing Cover Gaskets (GM Part #24435052)

1. Park the car, put it up on ramps or jackstands. You can keep the driver's side on the ramp, but if you plan on setting timing the long way, put the passenger side on a jackstand, as you will have to take your wheel off, as well as a splash shield to get access to the timing cover. Unplug your fuel pump relay, start the car and let it run itself out of fuel. (This releases the fuel pressure from the fuel rail so you don't get a facefull of fuel.) Disconnect the battery.

2. Open the hood. (I took my hood completely off - with some help, of course. It is only 4 bolts and is extremely helpful to have the extra headroom.) Remove the belt from the supercharger by using a 15mm open end wrench on the tensioner. It's best to remove the belt from the engine bay instead of just leaving it aside.



3. Remove all electrical connections and sensors from the supercharger and throttle body assembly. Also remove the coolant temp sensor, the barometric sensor, and any and all vacuum lines.





4. Disconnect the air intake from the throttle body. The throttle body does not need to be taken off of the supercharger for this project, but it is a good idea to take it off and clean it up, since it's already off the car. Also, the air intake does not need to be removed.

Throttle body off, disconnected from air intake


5. Remove the supercharger by removing the 4 bolts that hold it to the intake manifold, and ensuring you have all sensors disconnected. Ensure that the 2 metal 'alignment tabs' remain in the upper left, and lower right holes of the intake manifold opening. These serve to correctly align the supercharger and hold it in place when you are bolting it back in.

Supercharger off.




6. Remove the fuel rail cover, and the 2 bolts holding the fuel rail down on the head. Taking care, pull out the fuel rail with fuel injectors attached. Ensure that the 4 plastic "seats" are on the ends of the fuel injectors, if not, remove them from the head and replace them on the tips of the fuel injectors. (*Note - it is not required to remove the fuel rail completely; it can be rotated and set to the drivers side of the engine bay. However, it is best to remove it as it can get in the way later on in the build. The fuel rail can be removed using 2 open end wrenches (21mm, 24mm) and pulling the 24mm against the 21 mm. The fuel rail end fitting can still be damaged in this procedure, so take care. Then remove the fuel rail from the feed line and unplug the injector harness. Set it aside.) Also remove the coolant breather line going from the left side of the engine to the overflow tank, and remove the coolant hose going from the head to the radiator.

Coolant bleed line and temperature sensor


Fuel rail cover off


Removing fuel rail with the 2 open end wrenches (21mm, 24mm)


Fuel injectors removed and set aside


7. Drain as much coolant as possible from the intercooler system. Remove the hoses that connect to the intercooler endplate. Remove the IAT2 Sensor located on the left side of the manifold. Remove the 7 intake manifold bolts/nuts going from the outside in, but leave the studs in place for now. Remove the alternator. Using extensions and universal joints, remove the elusive 8th hidden bolt behind the intake manifold. Support the intake manifold from underneath and remove the 2 studs. The intake manifold can now be removed. P.S. This would be a GREAT time to do the dual-pass intercooler endplate.

Location of the 8th bolt underneath the Intake Manifold. It is just right of center behind the black wire loom.


Stock 4-pass endplate


Dual-pass endplate


Laminova core. 1 of 2 that needs to be taken out and repositioned.


Dual-pass endplate installed




8. Remove the valve cover breather hose. It connects from the valve cover all the way to the air intake. Remove the exhaust manifold/header. There are 10 studs and nuts that hold it on, as well as a heat shield. If you need a diagram of where the bolts are located, look at any aftermarket LSJ header pictures on various websites.

9. Remove the spark plug cover, coil packs, coil pack harness, and camshaft position sensor located on the exhaust cam, on the back side of the motor. Remove the grounds from the spark plug valley.

Spark plug cover and coil packs removed.


10. Remove the valve cover. There are several bolts located all around the valve cover. These do not need to be removed in any specific order. Remove the chain tensioner bolt from the back side of the head, located on the passenger side, underneath the exhaust ports. Remove the bolt on the front side of the head next to the belt tensioner with an allen key. There is a small bolt inside that needs to be removed. This bolt holds a chain guide. Remove the chain guide over top of the cam gears. Remove the cam gears to remove the timing chain. Use a 15/16 open end wrench and slot it on the intake cam. Using an 18mm box-end wrench or socket, loosen the cam gear bolt, but DO NOT remove it yet. Just slightly loosen it. Loosen the exhaust cam gear bolt, then remove both.

Valve cover removed.




(*Note - if you are good, and don't want to take off your timing cover to reset the timing from the crank up, you can mark the cams and the chain before you take off the cam gears. However, you have to keep the chain constantly held up, to keep it from falling off the crank. You can do this a variety of ways, but do NOT let it slip off the crank; you'll have to take off the timing cover and set it the long way if you do.)

Taking off the cam gears


Cam gears off

[Tennpenn83]

11. The head should be ready to come off. The head bolts need to be removed in a specific order to prevent the head from possibly warping. There is a diagram in the GM Sport Compact Performance Build Book that shows this order. This is where you will need a inverted #8 torx bit to remove 4 bolts on the passenger side of the engine. Remove them from the engine starting from the one closest to you and working towards the back of the motor. After you have removed the 4 torx bolts, there are 10 main head bolts. Remove them in this sequence : bottom left, top right, bottom right, top left. Move in one, then remove bottom left, top right, bottom right, top left. Remove the last two in the middle, bottom then top. (If that doesn't make sense to you, look it up in the build book or online here) The head should be ready to come off.

Taking off the 4 torx bits


Taking off the head bolts, in sequence




12. Remove the head, preferably with some help. You will notice a lot of coolant and possibly oil come out and make a mess everywhere. Remove the head gasket, and ensure the two alignment tabs remain in the block (just like the ones in the intake manifold to align the supercharger). Right now would be an opportune time to get a port/polish done on the head, and possibly install higher rate valvesprings. It is best to at least get the head checked for deformation/warping, and to possibly get it milled.

Head being removed.








Head removed, showing pistons and leftover coolant.




Head gasket being removed.


13. Remove the oilpan by taking out all of the bolts (there's quite a few, and some hidden/hard to reach). Make sure to get all of them. Using a prybar, pry on the oilpan at various points until it comes off. You will now have access to the crank and rods, which are accessed through the main girdle.

Oil pan off.


Oil pan off, showing main girdle, and the crank and rods behind.




14. Rotate the crank (clockwise) by using a ratcheting wrench or socket (22mm IIRC) on the crank pulley bolt. Rotate until the #2 and #3 pistons are at TDC. Unbolt the #1 rod cap bolts and, being extremely careful not to nick the crank, push up on the bottom of the piston with a long extension or screwdriver until it comes out. Take out the piston assembly. Check the rod bearings, and the crank journals. If there is any sign of abnormal wear, you will need new rod bearings. If your crank journals have abnormal wear, you have much more work to do. After the piston assembly is removed, check the sleeves for abnormal scratches or wear. The sleeves should be honed out to remove the glaze that will accumulate on the sides. Use extreme caution in doing this, as any debris could fall on the crank journals and could cause extra wear once the assembly is re-installed. (*Note : if you are attempting to hold up the chain and not let it fall off the crank, keep this in mind as you rotate the crank to remove the pistons.)

Rotate crank by using a wrench on the crank pulley bolt, located on the crank pulley at the top of the picture. This picture also show the main girdle.


15. Take the piston assembly and remove the wrist pin circlips on either side of the wrist pin, and remove the wrist pin itself. The pistons will be separate at this point. If you are using the wrist pins provided by Diamond, you will need to hone out the small end of the rods to .907" (stock is .906"). The stock wrist pins are pretty stout, so it's your call if you would like to replace them. Install the new piston by doing the following, in order. With the piston by itself, install one of the 2 wrist pin circlips. Slide the wrist pin through one open side of the piston, then through the rod end, then through the other side of the piston. Then, lastly, reinstall the other wrist pin circlip. It is important to make sure the rod is oriented the same direction with the new piston as it was with the old.

16. Using your new pistons, it is time to put on the new rings. The Total Seal rings are a file-to-fit, and, depending on your application, the ring gap will vary. Again, it's your call. Also, be sure to check the rings, to see if there is a "top side" that needs installed top facing up, per each ring. Total Seal provides a detailed list of instructions that will help you decide what gap, and will show you which rings need to be facing up. Put your new rings on in this order from bottom up using your piston ring spreader : thin oil ring, accordion ring, thin oil ring, oil separation ring, top ring.

Using a piston ring spreader to remove the old rings. This step is not required if you are using aftermarket pistons AND rings.


It should look like this when finished.


Stock Piston vs Diamond Forged Piston


17. Using a piston ring compressor, tighten the compressor as tight as you can go, apply a light coat of oil on the piston skirt and line up the piston to drop back in. Apply some Torco assembly lube to the rod bearings. Ensure the valve reliefs on the pistons are pointed the right way - the Intake valves will be bigger and will be towards the front of the engine. Also, there should be a marking on the aftermarket pistons to show which side goes towards the front (on the Diamond Pistons, it's an F, located in between the intake and exhaust valve reliefs - this "F" should go towards the left). CAREFULLY line up the new piston and gently tap it into the cylinder using a rubber mallet or a hammer with a rubber handle (tap using the rubber handle so as not to damage the piston). Hopefully, you will have a friend down below who can "catch" the rod end as it's coming down and line it up with the crank. Then, using new rod cap bolts, re-install the rod caps. If you are using stock replacement bolts, torque them to 18 ft/lb plus 100 degrees. If you are using aftermarket bolts (ARP or A1), apply the thread lubricant to the threads, torque them to 35, break them loose, torque to 35 again, break them loose again, then torque them a final time to 65.

18. Repeat for the other 3 pistons.

Forged pistons installed. (also installed are the ARP head studs - minus the bolts)


19. Use some gasket maker, and re-install the oilpan.

*NOTE* I should also note that, if you are doing this with the motor in the car, the ARP headstuds should be installed AFTER the head is replaced on the block, NOT as shown in the picture above. The head will not clear the cowl/firewall with the headstuds already installed, sticking up.

20. Reinstall the headgasket, the head, and head bolts/studs. Tighten the bolts/studs in the reverse sequence that you removed them. If you are using stock head bolts, torque them to 22 lb/ft plus 155 degrees. If you are using aftermarket studs, install the studs hand tight, then install the nuts in 3 step increasing intervals. Following the proper sequence, torque them to 35 lb/ft. Then make another round, torquing to 60 lb/ft. Then, make a final round to 85 lb/ft.

21. (If you were able to keep the chain from falling off the crank, skip this step) Ensure the passenger side is supported be a jackstand, not a ramp. Take the wheel off, then remove the splash shield, to gain access to the timing cover. Remove the timing cover by doing the following : support the engine from underneath (i.e. a 2x4 on a jack underneath the oilpan), remove the passenger side motor mount, idler pulley, tensioner, crank pulley, and all the bolts that hold on the timing cover (there are many). Remove the cover. *IMPORTANT* To set the timing, rotate the crank so that the mark on the crank sprocket is at roughly the 5 o'clock position. Line up the purple colored link on the timing chain with this mark. Line up the intake cam gear with the diamond pointing towards the 2 o'clock position (looking in from the passenger side). Place the blue colored link on the timing chain with this diamond. Line up the exhaust cam with the triangle pointing towards the 10 o'clock position. Place the red colored chain link over this mark.

[Tennpenn83]

22. Tighten the NEW cam gear bolts to 65 lb/ft. Replace the timing cover (replace gasket if you want) and re-install the idler pulley, tensioner, and crank pulley - with a new bolt for the crank pulley. Replace the motor mount as well.

23. Replace the small chain guide bolt and tighten to 89 in/lb, and replace the cover bolt and tighten with an allen key. Pre-load the tensioner by placing a flathead screwdriver in the slot at the end and twisting (a vise or vise grips may be required). It will "set" and stay compressed. Place it in the hole and ensure it lines up with the slot on the tensioner chain guide. Tighten it 1/4 turn past hand tight. Using a long extension or screwdriver, "bump" the tensioner from inside the head until it snaps into place. You will know when it releases. It is quite loud, and the chain will have no slack.

24. To ensure you have the timing set correctly, or in case you are just paranoid as I am, SLOWLY rotate the crank. If you feel any sort of resistance or contact at all of the valves with the tops of the pistons, STOP!! You have done something incorrectly, and need to start over with re-assembly.

25. At this point, it's just putting everything back together in the reverse order you took it off. Make sure the electrical connections and sensors are all plugged in, and that all vacuum lines are attached. Use conventional motor oil to fill up the first time. After everything is back together, with your fluids topped off and your battery connected again, cross your fingers and start her up. Let her warm up to operating temp, and check your fluids again.

26. Breaking in the rings is vitally important to keeping the motor happy. Do NOT just go out there running 20 psi through brand new rings. Do NOT go take a 3 hour cruise on the freeway.
Everyone has their own ideas on how to break in new pistons/rings. This is my personal opinion on how I did it. DO the following :
- vary your rpms, a lot. If you keep your rpms at 3k rpms during the break in period, then your rings will probably not be happy when you try to take it to 7k. Go to every rpm, and do not stay at any one rpm for very long. Drop to idle, go to 5k, etc...
- Limit your boost. On an N/A motor, you could just break it in on a dyno and not worry too much. On a boosted motor, you have to be a bit more careful. Watch your boost gauge. Try to keep it in vacuum only for the first 500 or so miles. During the second 500 miles, keep control of your right foot and slowly introduce boost.
- At 500, and 1000 miles after the install, change your oil. Keep an eye on your fluids during the whole break in period. Also, look closely at the oil to ensure there are not any metal shavings.
- I would recommend getting a compression test done at your 1000 mile oil change, to ensure the rings are seating properly.

I am sure there are things that I forgot. I will do my best to review this thread for errors. I will also try to include more pictures and references. If there is anything that I am completely wrong about, please let me know. If you are about to start a project such as this, I hope that I will have been of some help to you. Best of luck to you, and most of all, have fun!

[WickedSS]

Funny, this thread pops up the say before we do this We can update or take any missing pics tomorrow

[Tennpenn83]

lol... this is one of the threads that i made on rlf, actually made it as a sticky if you can believe it.

through my ninja skills, i got it back. i should copyright it

[elite_Cyborg]

Where the cylinders honed any?

[ndbalt07]

pretty nice. I'm doing this but I took my motor out so I could hone the cylinders. Did you hone them at all?

[Tennpenn83]

yes. there are also a few other things that i forgot to mention, such as setting piston ring gap (determined by the user/motor/application), milling the head or block, checking tolerances. i will see if i can revise it down the road.

[billabong9687]

btw, one thing that should be added, there is a 13mm bolt that threads into the bottom of the block near the front cover by the crossover tube. That would have saved us from soaking up coolant from all the cylinders

[billabong9687]

pretty nice. I'm doing this but I took my motor out so I could hone the cylinders. Did you hone them at all?

You can hone with the motor and crank still in the car

and jordan, when sesting these rings you don't want to drop boost, you want to get heat into the rings to help them see what they will when done.
I think the reason your rings went the first time was lack of heat and driving lightly

end thread jack/

[Tennpenn83]

you might be right on that one josh, i put the rings through a lot more boost the second time. they seem to have held just fine for almost a year now.

and i really wish i would have known about that coolant drain plug before the first time.. lmao

[cmiller8006]

You can hone with the motor and crank still in the car

and jordan, when sesting these rings you don't want to drop boost, you want to get heat into the rings to help them see what they will when done.
I think the reason your rings went the first time was lack of heat and driving lightly

end thread jack/

Only problem with that is you are removing small amounts of metal and stone and that can get in the bearing clearances. The only proper way to me to do it is to remove the motor and then make sure it is cleaned very well afterwords.

[cmiller8006]

A couple other things I noticed when I did my motor, you really need to mic everything. My new rods were a bit to tight and needed to be opened up on the big end a bit. Here is a great type of ring compressor to. The cheap ones work well but these simply allow you to push the piston in to the block.

[qwikredline]

cmiller good points. I always look for a good cross hatch in the bores, and measuring everything is important, which is why, more and more I let the pro's do that part of the machine work> As you say, doing it out of the car where you have control of cleanliness is just so critical to a successful engine build, and if there is any taper in the bores, a machine (Sunnen ) hone is best centered off the crank centerline.

Hey thread jack did u run meth when u did those "fastest stock LNF" quarter mile runs?

[cmiller8006]

cmiller good points. I always look for a good cross hatch in the bores, and measuring everything is important, which is why, more and more I let the pro's do that part of the machine work> As you say, doing it out of the car where you have control of cleanliness is just so critical to a successful engine build, and if there is any taper in the bores, a machine (Sunnen ) hone is best centered off the crank centerline.

Hey thread jack did u run meth when u did those "fastest stock LNF" quarter mile runs?

I did, I ran the meth for about three months total. And sorry to the op for the thread jack lol.

[qwikredline]

to finish thread jack, Tennpenn is a good guy lol .Meth on a di LNF good/bad/indifferent/

[StevesBlack06]

the only thing i see wrong with this is the leftover coolant. the problem being, the coolant will get down into the thread pockets for the head studs and it could make them to seem as if they are bottomed out when really they have just compressed all the coolant in the bottom. over time the coolant could work its way out or evaporate and could be a potential cause of a head gasket failure or lifting/warping the head. its not a for sure thing but i believe this is what happened to my buddies first build. its a long shot but its possible

[cmiller8006]

One more thing. I didnt see if you said to retorque the headstuds at the 500 mile service. It does not say you have to but I spoke with ARP and they say it is a good idea. I am not critiqing you either just so you know lol. Just trying to make it easier for the next person.

[StevesBlack06]

i always retq. and 9 times outta 10 some of them have loosened up a touch

[billabong9687]

On the coolant in the thread hols, we cleaned those out with shop towels and brake kleen, when I talked to arp, they told me the re tq'ing was for the old white pack of lube sent with bolts, with the new blue pack its not as necessar
y......but I do anyway