head specs

E

Egov

Junior Member
Hey everyone! Just got my 1930 aa running and noticed a little head gasket leak. Figured I'd pull it and have it milled a little for higher compression. My machinest told me to get all the specs and measurements for the head(he's done big flatheads but never a model a) just to make sure its stock and hasn't been cut before. Does any one know where I can find these specs?
Bert's model a is about 25 minutes from my place but ya know the more information the better!!

Also has any one done the t5 ****** swap into a aa yet and if so what kit did you use and was it pretty basic to do or a pain?

Sorry bout repeating the t5 stuff, new to the model a world at 24 years old lol
 
Little higher compression is right. You are FAR better off with a commercial HC head as there is more to it then shaving the head, the combustion chamber is a different shape in true HC heads.
 
You can't take enough off to make a difference. Go for a Snyder head your money
will be well spent.
 
I agree, shaving the stock head is like a spit in the ocean. You are lucky that Bert's is so close to you. My friend and I picked up high compression heads from Bert's when we stopped there some years back. These are the Snyder's 5.5 heads.
 
Although the head is a couple of inches thick the thickness between the head surface and the water passage is not very much and milling enough to increase the compression will probably result in cracks. When I find a head that has been milled very much I pass on it. You can tell how much a head has been milled by looking at the depth of the recess to clear the piston. Another problem you might encounter is the piston hitting the milled head, be sure to check to see if your piston comes above the surface of the block (from the block being surfaced over the years) and that there is enough clearance. My suggestion is as others have said, buy a high compression reproduction cast iron head and don't even mess with the stock head. Note that the head in the photo is an A 6050B head (Police head) but the area of concern is the same.

Charlie Stephens
 

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On a stock A Model engine you need 0.030 + all your clearances
i e con rod bearing gap + main bearing gap + piston rock
aim for 0.040 cold piston to head clearance
head gasket manufacturer will supply compressed thickness
 
I have used heads like the one Charlie shows and have never had a problem with clearance. I have an 8:1 head that is flat with no counterbore used with a copper gasket and it does not hit.
As far as cutting the stock head to increase compression, I have one that has been cut .125 and it didn't increase the ratio but about .02.
 
I would just re-torque the head first to 55 Ft lbs. and see if it fixes the leak. The combustion chamber is shaped so differently from a stock head to the high compression type that shaving doesn't get you much for what you pay to have it done.
For the T5 question, use the search feature and go advanced. Then enter your criteria and check the Model A section and you will most likely find all the answers to your A related questions.
 
Thanks for your input everyone! Gonna have to break open the piggy bank for a new head but think it'll be worth it in the long run!
 
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