Piston Clearance
Thread Starter
Safety Car
Joined: May 1999
Posts: 3,651
Likes: 5
From: Atlantis
Cruise-In I Veteran
Piston Clearance
Hey guys,
Getting ready to rebuild my engine.
Will my domed pistons work eith the 113 D port heads?
I've got .125 domes.
I haven't removed the heads yet. Some heads have a protusion at the spark plug hole that will intefere with the domed pistons. Thus you can only run flat tops.
My heads are on a '91 Vette.
Will my pistoneys clear? Will I have to modify the combustion chamber to clear the dome pistons?
Nuttin but questions.
Getting ready to rebuild my engine.
Will my domed pistons work eith the 113 D port heads?
I've got .125 domes.
I haven't removed the heads yet. Some heads have a protusion at the spark plug hole that will intefere with the domed pistons. Thus you can only run flat tops.
My heads are on a '91 Vette.
Will my pistoneys clear? Will I have to modify the combustion chamber to clear the dome pistons?
Nuttin but questions.
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 4
From: Houston TX
Re: Piston Clearance (VetNutJim)
Your clearance depends on valve lift, cam timing, size of the valve reliefs and valves, how much the heads have been milled, how much the block has been decked, head gasket thickness, etc, etc, etc. Basically, the only REAL way to know is to install the pistons and heads and measure your piston to valve clearance then. Sorry I couldn't be more help, but there are too many parts who's measurements are too hard to stack up and get to within a few thousandths accuracy.
Thread Starter
Safety Car
Joined: May 1999
Posts: 3,651
Likes: 5
From: Atlantis
Cruise-In I Veteran
Re: Piston Clearance (CorvetteZ51Racer)
Thanks for the input.
I'm not too concerned about the valve to piston clearance at this time.
It's the piston to head clearance at that protusion in the head combustion chamber that is bothering me.
Deck height is .030 and the head gasket will be .035.
The piston dome is .125 on one set of pistons I have.
I've got another set with .250 dome.
With the .125 dome pistons with the deck height and the gasket height, the dome protudes .060 into the chamber PAST the block deck into the combustion chamber.
My question is this: Do the 113 heads have the protusion located in the imediate vecinity of the spark plug hole that "some" of these late model heads have.
I haven't selected the camshaft so am not concerned about the valve/piston clearance right now. I'll control that with camshaft and rocker arm ratio and maybe even flycutting the valve reliefs in the pistons.
Maybe this will make the question clearer and eliminate all those "variables":
Is anyone running pop-up pistons with the 1990 or 1991 GM Aluminum Corvette Heads?
Is there any additional clearancing that will have to be done either to the head combustion chamber or the piston dome.
Anybody??
I'm not too concerned about the valve to piston clearance at this time.
It's the piston to head clearance at that protusion in the head combustion chamber that is bothering me.
Deck height is .030 and the head gasket will be .035.
The piston dome is .125 on one set of pistons I have.
I've got another set with .250 dome.
With the .125 dome pistons with the deck height and the gasket height, the dome protudes .060 into the chamber PAST the block deck into the combustion chamber.
My question is this: Do the 113 heads have the protusion located in the imediate vecinity of the spark plug hole that "some" of these late model heads have.
I haven't selected the camshaft so am not concerned about the valve/piston clearance right now. I'll control that with camshaft and rocker arm ratio and maybe even flycutting the valve reliefs in the pistons.
Maybe this will make the question clearer and eliminate all those "variables":
Is anyone running pop-up pistons with the 1990 or 1991 GM Aluminum Corvette Heads?
Is there any additional clearancing that will have to be done either to the head combustion chamber or the piston dome.
Anybody??
