Ok so here's the deal. I didn't want to take any chances so I sold the SRP pistons I had (to many horror stories)... which were 4.030. But since I had the block worked for the the bore sizes varied from 4.029 - 4.032(3). Now I am going to purchase some diamond pistons (-24cc) but I see a set of the .030 and one that is .040 which should I get. I not know if it would be a risk getting the 4.030 pistons because I do not know how bad there piston sizes vary. WHAT SHOULD I DO?

 

anyone?

 

If youre bore clearance only varies a few thousands then a .030 over piston will work. If the pistons measure inconsistant mix and match your set to go with your tighter or looser bores.

 

Quality pistons will vary no more than .001 (or less) across a set of eight. My CP pistons are virtually indistinguishable from one another when measured 3/4" from the tip of the skirt. You won't know until you measure the Diamond pistons at the skirt and factor in the recommended piston-to-wall clearance. You might wish to contact Diamond and ask them if their +.030 piston will work in a +.032 bore.

 

check the bore with a tq plate on it.


normally you don't finsh the bore until you have the pistons in your hand....

 

they were finished to srp pistons. I will contact diamond to see what they think. I really don't want to go bigger. But will it i have too.

 

Realize also that the piston will expand when it gets hot. See what the clearance window there is.