Stock 12v Piston Protrusion

S

seeker1056

gear head
Joined
Aug 3, 2006
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Ok so I read like 50 different threads on what stock piston protrusion can/should be on a 12v.

every one of them devolved into opinions, or went totally off topic, rather than giving the actual specs.

I am not interested in piston to head clearance discussions, or valve to piston clearances, or head gasket thickness band aids etc which is the other digressions those threads went to.

My factory shop manual doesn't cover this.

The closest I could come to, from those various threads, was maybe .019 - .027 protrusion as acceptable?

Is this correct - or does someone have the actual specs for this?

thanks in advance
Ken
 
From page 9 - 175 of the 1996 factory service manual: 0.024-0.028 in.
From page 9 - 284 of the 2001 factory service manual: 0.024-0.028 in.
 
My 12v is a '91 IC motor w 200k. When I mic'd mine I got .19-.27 and everything in between the first couple times. That was taking measurements from the front of the piston. Differences between them had me a lil worried so did both sides of each piston several times duplicating the process as closely as possible and .23-.27 was as close as I cold get 'em to each other.


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FWIW if using the downloaded 1995 service manual, pages 9-174 and 175 are missing. These, by the book(which he asked for) numbers are taken over the wrist pin.
 
yes - mine is a 96 motor, and the specs akadiesel gave are what I am looking for
thanks very much
mine range from .021-.024 if I am measuring correctly with my dial indicator
 
They are by no means the only measurements that will yield a good build. It all depends on why its diff and your end goal.
 
it was because we had the block decked, and the pistons were custom machined before I got them at .010 of the top
Just needed to know where to start checking
thanks
got my answer
 
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