Milled Head?

J

jeepguy1948

Well-known member
Is the “Snyders High Compression Head” simply a stock head that’s been milled or are the compression chambers different (or anything else different for that matter).
 
jeepguy1948 said:
Is the “Snyders High Compression Head” simply a stock head that’s been milled or are the compression chambers different (or anything else different for that matter).
Click to expand...

A quick look by me determines that it is its own entity - and not merely a milled LC head.

You may see it differently. You can compare the combustion chamber shape somewhat by looking at Vince Falter's page which has been captured by archive.com (below)

https://web.archive.org/web/20250516072056/https://www.fordgarage.com/pages/headcompressionratio.htm

Note also that Snyder's offers TWO heads, one of which is currently "discontinued" or "out of stock." Not to say that either of these could not be found from other suppliers. Stock with any seller tends to be "hit or miss."

Joe K
 
Snyder's high compression heads are new made in USA heads. You can't really mill enough off of a stock head to gain any appreciable increase in compression because the chamber is so huge.
 
The only reason to mill a head is to clean up the surface, and then just a light cut, just enough to clean it up. You also have to recut the piston clearance pockets. As Flathead said, for a Model A you cannot cut enough to make any difference. But I did have a cut "low head" on my Model T. It was cut about 7/8 inch and was into the water jacket in places. The head gasket sealed off the places that were cut through. It made a big difference in the performance of my T.
 
The Master Cylinder mentioned combustion chamber shape. This is just as important as the compression ratio. The shape has to be designed to easily allow the intake air/fuel to flow through the valves and down into the cylinder. It also has to be designed to take advantage of the squish area between the piston and the head to maximize the turbulence during combustion. The old Harley Davidson racing flat heads are a good example of a well designed combustion chamber.
 
Thanks for the info Guyz. I won’t be trying that myself but instead am going to use a Brierley head. I already have a Brierley head on another car and am quite happy with it but would have tried the “cheap route” on this motor had it been beneficial.
 
The cylinder head sits upon a compressible thick gasket. In addition, the head has some flexibility to it. I do not understand why it is necessary to mill a cylinder head. I have never done so and I have not had any negative consequences. The only problem I have encountered is the classic head gasket burnout between cylinders 3 & 4 which has nothing to do with the flatness of the head.
 
The 94 YO old timer in our club indicated that the head could be milled a fair bit, the water pump flange is the limiting factor. I would have to agree that the combustion chamber is huge so not a lot of benefit cutting the head as well as the actual shape of the chamber is important as well.
 
Years ago when I installed my Snyder's High Compression Head. I took note of this.


The chamber shape was a more definite hart shape compared to the early 1928 Head.


I installed a spark plug in the Heads and flipped them upside down and level.


Using a syringe I filled the combustion chambers of the heads to the overflowing point on both.


The early 1928 stock head held 216cc of liquid.


The Snyder's 5.5-1 Head held 144cc of liquid.


That was quite awhile ago but I would think it would still be the same.
 
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I remember hearing/reading somewhere that the early heads were a little higher compression than the later ones. Not enough to be noted however. Dont know if that is true.
 
Full Race, No, it was 7/8. I had to use short head bolts.

Added: The Model T heads do not have the squish area like a Model A. They just have a big combustion chamber above the pistons. So you don't have to worry about the head crashing with the pistons.
 

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