I think you'd be happier with standard gap rings anyway. I can't understand how gapless rings deal with piston expansion and tip when the engine wears.

I did some digging and found an article that states what I was thinking too:

http://racingsecrets.com/article_racing-10.html

 

yep, i think i will too. heres the new ones

if i set quench at .040, can i be sure that P2V clearance is good?

 

You can't be sure unless you rotate the engine around and check p2v at the overlap. There's no other way to be aboslutely sure. Were it my engine, I'd spend the extra hour or two degreeing the cam and checking the clearance with a dial indicator.

 

my old .030 pistons were already clayed. the .040 pistons which are the same model just need to be put on the lathe and turned down .100 because thats what was done to the .030's.

 

What pistons did you end up using?

 

my old pistons were KB356 +30, the new ones are KB356 +40. same compression height and everything, so just need to take em down .100 just like the 30s, right?

do you use gapless or conventionals?

 

just talked to my machinist.

he said reclaying wouldnt be necessary, we'll just take .100 off the new set as well, since they are the same piston.

he said they originally planned to set quench at .040, but after doing some research and consulting other machinists, came to the conclusion that .060 would do better with that particular build. any objections?

 

What is your final compression ratio, and cylinder pressure? Those are not the same calculation,btw.

I know this is a bit OT, but festrictor plate engines can run way high compression ratios, but the plate inhibits the amount of air that gets into each cylinder, so the actual cylinder pressure is much lower.

I am by no means an expert, but I do try to read up thoroughly before I attempt anything that has been done a million times with sucess, and I would cosider each build of a non factory standard sized engine a unique build unto its own. Better to know everything up front, then find out when you turn the key.

If a. 060 quench is suggested by your builder, he's built one before, and it ran right , id take his advice over mine, but I'd also pick his brain (or the guy who suggested it as to why, just so I would know and could research the answer myself.

 

will taking .100 of the piston crown reduce volume? current piston volume is -23.5cc which yields 10:1 compression with a .050 gasket. i am going for right at 10:1, but dont know if piston volume will change after they have been lathed. how do you calculate psi?

restrictor plate??

 

Are those slugs forged ? How much were they if you dont mind ? I wanted to go forged so i could spray but the wallet said otherwise. Got any new pics of the progress ?