LT1-LT4 Modifications 1993-97 Gen II Small Block V8

LT1 Piston to deck clearance vs. deck height?

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Old 09-17-2007, 12:24 PM
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Default LT1 Piston to deck clearance vs. deck height?

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?
Old 09-17-2007, 12:58 PM
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Both are one in the same from my understanding..
Old 09-17-2007, 12:58 PM
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Most stock unaltered blocks are around .027(ish)


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Old 09-17-2007, 01:15 PM
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I have measured them every where from .022-.034
Old 09-17-2007, 03:40 PM
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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.
Old 09-17-2007, 03:44 PM
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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.
Old 09-17-2007, 04:04 PM
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Originally Posted by ulakovic22
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.
that leads me to believe the faq is inaccurate then. always wondered about that.
Old 09-17-2007, 04:34 PM
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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
Old 09-17-2007, 05:38 PM
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The few LT1s I have measured have been .022-.027



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