Head gaskets

G

Geo. H

Senior Member
A friend has the heads off of two Model A engines. One of the heads is a stock Model A head, the other is the optional 5.2 compression ratio police head with the block letter "B."

He has purchased the new silicone style gaskets, and he notes the the instructions say to use a Model B style gasket rather than the Model A style gasket if you have a high compression head such as a police head or a Snyder's head. Do any of you know why they would suggest this? I don't understand why it would be better to use a Model B gasket when neither the block nor the head is a Model B. Thanks for your help and experience.
 
I used that gasket on my Snyder 5.5 and it leaked initially as I torqued it to the 55# they recommend. I then read a thread here and (Tom Wesenberg?) said to torque to 60-65#. So I went to 60# after a couple of retorques and no more leakage. Oh,...and we machined the head flat. The only difference between the A and B is two little holes in between 2 and 3. Other than that you can use the silicone A gasket.

Mike
 
Re: High Compression Head Gaskets

Hi Geo.,

For what it is worth, this is what was experienced:

Acquired a 1932 B engine with an A vintage Police head, (marked with a raised B on it), that was successfully used in a boat for 17 years from 1932 until about 1949. When I removed the Police head, it had the old time copper Model A head gasket installed with non-hardening Permatex No. 2 gasket sealant.

Next used this Police head on both the Modle B engine & a Model A engine in the 1950's & 1960's with standard copper gaskets with Permatex No. 2, using numerical bolt tightening sequence, while never exceeding torque of 55 ft.lbs.

Recently acquired a 1930 Briggs Town Sedan with a vintage Police head on an A engine. It had a standard copper A gasket; however, reassembled it with the modern silicone gasket sold by today's Model A vendors with no head gasket sealant -- again torqued in recommended bolt sequence to 55 ft.lbs. -- no leaks.

Hope this helps.

H. L. Chauvin
 
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