Identifying a high compression head

oriondal

oriondal

Junior Member
I’ve seen high compression heads described as looking original. Is there an easy visual way to tell the various compression ratios and original heads apart on an installed engine?
 
oriondal said:
I’ve seen high compression heads described as looking original. Is there an easy visual way to tell the various compression ratios and original heads apart on an installed engine?
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Usually no, unless there is a manufacters mark on top of the head, which older heads had. But new ones look exactly like an original.
 
oriondal said:
I’ve seen high compression heads described as looking original. Is there an easy visual way to tell the various compression ratios and original heads apart on an installed engine?
Click to expand...

Yes kinda, but the word easy might be easier for some over others. The original head should have the delta foundry mark cast on the water pump mount, and the Brumfield had the BF logo and other markings. If you have studied the shape of the original heads enough, you can also discern the slight difference of the top of the BF. The Snyder heads have a small circle cast that has what looks like centering punch marks on the top. Now for some of us who have use sneaky tactics to camouflage an aftermarket H/C head to appear as an original head, all bets are off then. ;)
 
Probably the best way is to look at the combustion chamber - and compare it to an original Model A chamber. Different makers of HC heads have different chambers and one can get a sense of who made it from the hidden side.

My X-ray vision isn't what it used to be.

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I think my X-ray glasses are in the same box with the Sham-Wow wipers.


Joe K
 
One thing I noticed is my 5.5 head from Snyder's is the H/C head physically smaller than an original.There was a thread that mentioned this a little while back. You do have to look close tho. Notice head gasket.

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All of the Snyder high compression heads I have seen have two round casting marks about the size of a dime. The photo in post #6 shows them, one on each side of a lug nut. The location varies with the different lots.

Tom Endy
 
The original police head had a heart shaped combustion chamber and a compression ratio of 5.2 . The Brumfield 5.9 compression head also has a heart shaped combustion chamber . Combustion chambers can vary in shapes and sizes with different heads . Most of the higher compression heads that I have seen use the heart shaped chamber .
 
As Dodge said, do a compression test. It cannot tell the difference between two heads with the same compression ratio from two different manufactures but it at lease tell the difference between a stock head and a 5.5 or 6.1 head.
 
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