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-   -   bbc question (https://www.racingjunk.com/forums/showthread.php?t=24157)

taps 05-06-2009 07:25 AM

bbc question
 
what is minimum piston to head clearance on steel rod bbc?

TS1955 05-06-2009 08:07 AM

I typically run "zero" deck clearance and a Felpro #1027 head gasket which has a compressed thickness of .039. So my piston to head clearance is .039. Hope this helps. I'm sure others do it differently.

TS1955

curtisreed 05-06-2009 09:46 AM

Watch your piston rock depending on how "big" your BBC is. RPM will also play into it some. Just some things to think about in the equation.

Curtis

ARUSSELL 05-06-2009 01:28 PM

We recommend a min of .040 between the piston and the head.

russ67chevelle 06-17-2009 10:00 PM

my motor builder said once upon a time they set up thier pistons .005 thousandths in the hole

curtisreed 06-18-2009 03:52 AM


Originally Posted by russ67chevelle
my motor builder said once upon a time they set up thier pistons .005 thousandths in the hole

russ,
That doesn't tell you what the p to h clearance is. You could still have .060".

Curtis

dparker 06-18-2009 05:01 AM

Plus the gasket....

desoto30 06-18-2009 01:24 PM

I think russ67 meant .005" = a "std" style gasket say 0.039" compressed & you'll generally be ok. X2 As doorracer says depending how "big" & rpm. I don't understand the last post.

dparker 06-18-2009 06:32 PM

I dont see what would be hard to understand. .005 in the hole plus the gasket .039 would give you .044 clearance, between the flat part of the piston and the head. Which is where most pistons hit. Especially if because of the piston rocking in the cylinder.

Tod74 06-18-2009 06:35 PM

Mine hit on the dome right by the intake valve...Motor was already together so I had to grind on a brand new set of heads. :(


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