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Technical 4-Banger Police Head Question

Discussion in 'Traditional Hot Rods' started by dicer2000, Nov 23, 2016.

  1. dicer2000
    Joined: May 25, 2016
    Posts: 69


    My grandpa's Model A has a police head (he thinks). It is on his Model B engine. We're hoping someone can give us more information on it.
    Such as, who made it (was it original Ford equipment)?
    Does it give higher compression?
    Was it only available at high altitudes?
    What kind of horse power does it add?

    Thanks for any insight you can give.

    Attached Files:

  2. tubman
    Joined: May 16, 2007
    Posts: 4,412


    I know nothing about this, but I have to ask : are there any markings or other physical indications that it is not a stock head? Is there anything other than grandpa's proclamation?
    1927graham likes this.
  3. 32phil
    Joined: Nov 24, 2007
    Posts: 44

    from New York

    Looks like a B block (like you said) and a stock(I think ) Model A head. I'm not sure what the big letter B means.
    It may be a hi po head of some kind.
    Try going on the Ford Barn and posting your question in the Model A section ....
    Those guys know EVERYTHING about Models As.
    loudbang likes this.
  4. dicer2000
    Joined: May 25, 2016
    Posts: 69


    "Not necessarily" he says. However, there is a small triangle that he believes helps to identify it. Obviously, there is also the "B" and a "5" stamped in the head. He got it from Martin Auto Salvage in Greeley, CO out of a police car.
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  5. The big letter "B" was used to identify it as a high compression head produced by Ford. The head was originally sold to police departments but later released to the general public. You can find more at:

    Charlie Stephens
    Last edited: Nov 23, 2016
  6. dicer2000
    Joined: May 25, 2016
    Posts: 69


    Charlie, I should have guessed that you would answer my "A" question. I think you answer all my questions! The funny thing is that my Grandpa's last name is Stephens (Ken) from Lamar, CO. Do you have any relations from that part of the country?
  7. dwollam
    Joined: Oct 22, 2012
    Posts: 794


    Yep, B engine with Model A high compression "police head" with the correct B lettering. Model B engines had a "C" cast on the head. Makes for plenty of confusion. B engine has different water pump than A. "B" high compression head uses Model A water pump. Cloudy enough yet?
  8. dicer2000
    Joined: May 25, 2016
    Posts: 69


    Thanks everyone. Great info!
  9. 5280A2
    Joined: Sep 8, 2014
    Posts: 111


    Compression ratio is 5.2:1 compared to 4.2:1 for the stock A head.
  10. Truck64
    Joined: Oct 18, 2015
    Posts: 3,699

    from Ioway

    ^^^ You'll never catch me Coppers!! Muhuhaaha!
    dicer2000 likes this.
  11. Fred A
    Joined: May 3, 2005
    Posts: 273

    Fred A
    from Encino, CA
    1. Upholstery

    Seem to many that the one point increase is a small improvement, but as often happens, it is the design of the chamber that is in the vein of the model B design but twice the compression increase of the model B. It is easy to see where the confusion between the 1932 introduced Model B, marked with a big C, and the 1930 intro of the "police" head, marked with a big B. I like the "police" head because it works well for my use of the manual advance of the Model A distributor. That manual control can confuse a driver without an understanding of spark advance. Many heads have been made and even currently available new with much higher compression making riding the spark manually, more difficult, risking destructive pinging. Estimating an increase in power is a product of a much more complex and likely optimistic guess. For the last 50 years I have used the "police" heads as a first choice for a modest but manageable improvement but also favor Model B cam and carburetor as a streetable minimum while a downdraft V8 carb is the next real improvement making the bargain Chandler Groves 94 right for me. Good Luck: Fred A
    dicer2000 likes this.

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