So I hit a jackpot in my opinion. After patiently waiting to purchase a motor for my 89 iroc, I came across a zz4 for sale, or so the guy thought. It turned out to be a BRAND NEW ZZ3 that had been sitting, sealed up tight for quite sometime. After taking the heads and intake off, I was able to confirm by the gm pink rods, and the p/n on the crank. This motor appears to have all forged internals, so I think I found myself quite a nice little motor. Anyway, my question is, does anyone know the pn appropriate for the flywheel which cam with the ZZ3? Is it the same as the zz4 flywheel? I read that these 1 piece rms cranks were balanced and as such require a counter balanced flywheel to achieve proper function. I would appreciate any help you guys can give me. Also, information on the ZZ3 is hard to find, and sketchy at best. Do you guys know where I can get the rundown parts list that the ZZ3 is comprised of? I would particularly like more information on the pistons used, I believe them to be forged as well. The cam seems to be roughlt the same as the ZZ4, with it's 208/221 pattern. Also, wondering what head gaskets to go with my AFR180's. AFR recommends the felpro 1003 for all aluminum heads smaller than 200 cc. Would this be a wise choice? Anyway, thanks in advance fellas, any help would be appreciated.

The 1987 and up small blocks with 1 piece rear seals all use the same flywheel, don't they?

I thought the ZZ3 uses the same flywheel as your IROC...

forged cranks use a balanced flywheel, not the thin type used on A4 irocs. I know that much, just looking for the right PN.

I'm confused you're looking for a flywheel but you have an auto.. are you converting to stick? Or did you mean a flexplate?

Flywheel, flexplate yeah same ****. They are all called flywheels.

It's a one piece rear main seal motor and it uses an 86 and up flywheel. If you do a 6 speed swap, you can use an LT1 flywheel.

I currently have a splayed main cap motor in my 1992 Z-28 with a ZZ3 steel crank in it, lunati rods, etc. I had it balanced with a GM 16 lb flywheel for a one piece rear main engine and then swapped a T56 in and switched to the LT1 flywheel. All you need is a stock flywheel/flexplate or equivalent for an '86 and up car and you'll be fine.

Poppycock.

Get this "balanced" stuff out of your head. You're just confusing yourself, and it isn't helping anyone else, either. The engine is considered internally balanced, but because the counterweight that is outside of the rear main bearing of every 2-piece rear main seal SBC can't be put outside of the round surface needed for the one-piece rear main seal, they put a little weight on the FLEXPLATE to replace the counterweight that used to be built into the crank.

Manual transmissions use a flywheel. Automatic transmissions have a plate that connects the crankshaft to the torque converter that incorporates a ring gear for the starter, called a "flexplate" by convention. It is not, by any stretch of definition, a "flywheel" - the heavy torque converter takes over that job for an automatic-equipped engine.

And, the flexplate a ZZ3 uses will be the same one every '86-up Gen I SBC uses.

The ZZ4 used PM rods and a metric oil pan drain plug. Some late ZZ3's had PM rods. The bolt spacing for the cam retainer plate also changed during the ZZ3 run. "Pink" rods aren't all that special (said knowing that mine has pink rods), PM are just as good or better. No ZZx engine is "all forged", as the pistons are hypers.

The ZZ3 and ZZ4 cams are identical.

Five7kid nailed it and he's 100% correct.

five7kid, if you can get me a part number/description of the pistons used in the ZZ3, then I'll believe it.

Go here:

http://www.crateenginedepot.com/pdfs/SB_zzengine.pdf

Scroll to page #4 (per the numbers on the pages, not the PDF)

PN 10181390, Piston, STD - W/Pin (Hypereutectic is cast aluminum with a high silicone content)

Look what boxes are checked beside it (the list is at the top). ZZ1, ZZ2 and ZZ3, they show the ZZ4 with PN 10159436 and list it as simply cast.


Go to google, put in:

10181390

Click the first link and you'll wind up here:

http://www.crateenginedepot.com/stor...0-P998C15.aspx

Another link will take you here:

http://www.gmpartsdirect.com/perform...CATID=856.html

Half way down the page, you'll find that part number (10181390) and it says:

High Performance Piston
This piston is for the 5.7L high output engine assembly; second design with ZZ1, 2, 3 I.D. Hypereutectic (high silicon) aluminum. This 350 standard or high-limit, pressed pin, high performance piston has a 9.8:1 compression ratio with 58cc head chamber volume (ID#10105168 or 10172749).

Or just click here:

http://www.gmpartsdirect.com/perform...CATID=856.html


Any other questions?

Thanks guys. Just what I was looking for.