I know the faq lists piston to deck clearance aound .017 but I always thought it was more like .025-.030? I guess what I need to know is what is the distance between deck height and piston to deck clearance and which one I need to plug into a compression ratio calculator?

 

Both are one in the same from my understanding..

 

Most stock unaltered blocks are around .027(ish)


David

 

I have measured them every where from .022-.034

 

Piston to deck clearance is how far the flat part of the piston sits above or below the deck of the block. Deck height is just that, the deck height of the block, like 9.2, 9.8, 10.2, etc. When calculating compression you need piston to deck clearance and as most have stated above, stock is around 25-35 thousands in the hole.

 

The LT1's and SBC's are in the Hole..the LS1's are out of the hole.
Mine is about .006-.010 out of the hole.

 

that leads me to believe the faq is inaccurate then. always wondered about that.

 

deck height for sbc/lt1 is supposed to be 9.025
in stock form lt1 supposed to be +.020 or .020 in the hole
when piston is out of hole it is refered to as( -) for calculating scr

 

The few LT1s I have measured have been .022-.027