I pulled my engine over the weekend to prep it for the D1SC Procharger thats about to be slapped on it. The motor was a 55,000 mile ZZ4 crate motor. While I have it out I was going to take it to a machine shop and get forged pistons and lower the compression ratio. I was wanting some suggestions as to what machine work I should have done to it since im just wanting to replace the pistons. I'm going to reuse the ZZ4 aluminum heads until I have enough $$ to get some AFR's, but as far as block work is concerned, im looking for suggestions. If the cylinders are ok, i'm probably going to leave them alone to save $$. Crank is forged so what should I do to it and the rods? Thanks in advance.

 

If the motor is apart and cleaned up everything can be checked. If budget is tight just fix what needs fixin. If the decks arent warped no cutting needed.If the rods and pistons are out and the crank spins easy, no align hone needed. mag the block for piece of mind, hone for the new rings and trust the machinest. Hopefully he is honest and doesn't talk you into rebuilding just for the sake of doing it.
Also, balancing the crank to account for the new pistons is cheap insurance.

 

i'd only get what it needed, no point spending money on needless machine work. get it cleaned, measured and inspected and see what it needs then do it.

 

Have 'em check the rods big end for roundness. Chevys like to go out of round over time/abuse. If they need to be trued up you might as well upgrade to better rod bolts while you're at it- the only thing I almost always do to a bottom end no matter what.

Everything else only on an as-needed basis depending on what he finds that is/isn't in spec.

 

If you change the rod bolts it's a good idea to have the rods resized.
Change the bolts to some good ARP's and have the rods resized.
Have the crank miked and polished.
Have you thought about upgrading the rods to some good h-beam ones?
Put in a new set of cam bearings and replace the frost plugs with the brass ones.
Have the cylinders honed for the type rings you plan on running.
Just a glaze breaking hone is all you want. No need to take away good metal.

Rip off a couple of gud'uns.... it's gud for ya!!!

Actually......
I don't know poop about this stuff but I did stay at a Holiday Inn Express last night.
So if someone tells you this is about the most stupid advice they've ever heard.... they're right!!! WooHoo!!! WoHOO!!!

 

I got the motor torn down and everything looks perfect, I decided not to take it to a machine shop, I'm just going to hone the cylinders for the new piston rings, and get the rods resized and ARP rod bolts. Right now i'm having trouble deciding on the right compression I want, cause I'm so limited because I have a standard 4" bore. Right now its looking like 8.6:1 w/ 58cc head. Unless I get a custom piston made. If I had the block 0-decked, the same piston would net a 8.9:1 compression...

 

running dished pistons i take it?do you need to do any work to the heads to getem to seal with the procharger?Sounds like its going to be nasty

 

Well, I found a different set of pistons that will net me 8.7.1:1 with the 58cc heads, they are D-cup forged Sealed Power. I don't think I'll have any problems with the heads sealing, but later on when I upgrade the heads ($$ permitting) I might have them o-grooved for those fel-pro head gaskets with the o-ring built into them, or just o-ring the block, but that's way off from now. I'm thinking I'll just start out at close to 12psi and eventually get 15psi and leave it at that.

 

see if sealed power offers them in a 0.005 overbore over what youve got now. reason i say this is becuase you can hone to tight clearances if your machinist pays attention to what hes doing. plus youl need new rings anyway. also get file fit rings. it the pistons are a bit loose. get them glass beaded and the rehone to fit them in the bores.


old school trick. yeah lowering the compression ratio to the neighborhood of 8.7:1 is a great idea. and the speed pro d cup dish with a 58cc chamber should work well. make sure to check deck height and gasket thickness along with true head cc.