Piston rock, quench and head gasket measurement

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khuebner250

khuebner250

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What's proper procedure for figuring out head gasket thickness in regards to quench? I've seen everything from. 032-.065 is acceptable. I have a stroker 360(414) with forged mahle pistons and forged steel rods.
I see people taking the piston protrusion and recession numbers and using the median. But I also see people say to use the highest out of bore number since that is the tallest it will be?
Here is a pic of the numbers I got using a deck bridge. This is highest and lowest while rocking pistons. I'm thinking a .045-.gasket thickness will equal out to .034-.035 quench on my tightest cylinders.
What's the consensus.

IMG_20190507_182259457.jpg
 
You have dished pistons. Don't waste your money. You can't get decent quench.
 
On your dish piston measure the outer ring portion (tallest portion) and select head gasket based on piston to head clearance. .040 is what I use.
 
khuebner250 said:
So, hypothetically, if my pistons are .015 out of the bore I can just put .035 head gaskets on it? Piston to head clearance is no big deal?
Click to expand...
Yes, it's a big deal. Granted, as already has been mentioned you aren't going to get ideal quench with a full dish piston. Piston to head contact can occur with as little as .028" total clearance. Piston rock along with thermal expansion can take that clearance away more than you think. Just make sure you stay within the middle of the numbers you posted above. When you start pushing the lower limit of it, ugly things can happen quickly if you misread measurements or get distracted.
 
You said an .045 gasket, and 4.03 bore pistons with the piston protruding a max of .011" at "max rock". I think you are fine with those numbers. If the pistons come out more, or a thinner gasket is used, you might not be... If you have .030 after taking into account the rock (which shouldn't be more than .010" on a 4.03 bore and modern piston material) you are fine. Least in my experience.
 
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