Well, we finally got our rebuild kit in, and they sent the wrong pistons in. so it got us thinking about whether to send them back and get the flat-tops or to keep the dished ones and see what we can do with them.

here is my question. I dont know if anyone has done this, but here goes:

If we keep the dished pistons, shave the head to raise our CR, and increase the duration of the cam to whatever the dished pistons let us do, would that be better than having a high lift/lower duration with the flat top pistons?

can we get the CR up (if we use the dished pistons) far enough to negate the CR loss of a dished setup by shaving the head, or getting a thinner head gasket?

note: we will be getting the head refinished anyway, so it wont cost us more to shave the head. also, we will port the valves 1mm at this time as well.

 

If it were that simple, my grandma could design engines.

Click: Engine Design Utility

Remember... if you shave the head more than ~0.080", you must use shims.

 

im playing around with this, but all i can seem to get is cr with a stock head. i dont know how to get the combustion chamber CC after shaving it .080 on an n42 head.

 

Change the deck height in the Block section.

 

darnit. guess im sending these back. well it was a good idea in theory! Thanks again Nismopick!

 

alright! the people at RPMMachine.com are great! for just the cost of shipping, they are sending me out itm flat top pistons, .020 over.

for all of you who are looking to rebuild your engine, the parts that they use are from "safety auto parts", and upon examination, they seem to be on the up and up. however, they have their information backwards as far as dished vs. flat top. they are under the assumption that the earlier n/a z cars had flat top pistons, and the 80-83 na's have dished pistons.

if you plan on ordering their rebuild kit, ($301+shipping) be sure you get the right pistons.

does anyone have a good resource on hand for a step-by-step rebuild of the 1982 l28e?

 

XenonS130 - S130 Reference

 

fair enough, fair enough. you must have that link saved somewhere lol. i hadnt looked there to see if it covered rebuilding. derp.

 

ITM are probably one of the best bang for the buck piston's out there for the L series