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Technical French Flathead cylinder heads

Discussion in 'Traditional Hot Rods' started by panheadguy, Apr 3, 2021.

  1. panheadguy
    Joined: Jan 8, 2005
    Posts: 1,031

    panheadguy
    Member
    from S.E. WI

    I have a set on my engine marked FMA. Cast into the top surface. Has anyone ever compared the performance characteristics of this head to other Ford cast iron heads?
    Like combustion chamber volume ?
    Better or worse than EAB or plain 59AB heads?
    Thanks
     
  2. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,912

    dirty old man
    ALLIANCE MEMBER

    Dunno, but I'll bump you back to the top.
     
  3. DBA711F5-8A80-40D7-B8AE-BCB5CABDF08A.jpeg I don’t know that the French heads would be any better or worse for flow or horsepower—-few heads made by ANY manufacturer are better or worse. There is NO such object made YET that will change a poor “breather” into a performance “breather” on a flathead v8.The realpower in Henry’s v8 is made thru cams,strokers, block porting and relieving, windage trays,bigger valves,etc NOT thru the heads. Many studies have shown Weiand,Edelbrock, Sharp,etc are among the best flowing heads flowed, yet, there is only 3-5 h.p. Difference in these gr8 products and ANY of Henry Ford cast iron!!! Why is this??? It’s because NOTHING that is designed is going to improve the flathead’s poor airflow designs by any gr8 margins!!! The main reason the flathead v8 did as well as it did is because it’s competition was mainly 6 and 4 cylinders. I think it is a challenge to have some “strong” flatmotors versus a stocker—-I have continuously studied them for 60 years and have learned a lot. Flatheads Forever!
     
    loudbang likes this.
  4. Beanscoot
    Joined: May 14, 2008
    Posts: 2,110

    Beanscoot
    Member

    It's easy to make the flathead heads flow well - just put a supercharger on them!
     

  5. Flat Roy
    Joined: Nov 23, 2007
    Posts: 486

    Flat Roy
    Member

    2X what Beanscoot said!!!
     
  6. panheadguy
    Joined: Jan 8, 2005
    Posts: 1,031

    panheadguy
    Member
    from S.E. WI

    I'm building another flat motor right now for my roadster but will leave the Frenchy in for now. That motor will be less stock. I have done very little to the Frenchy other than throw dual 94's on it and drive. Kinda fun when people ask what the FMA stands for?
     
  7. Bill Kuran
    Joined: Nov 25, 2020
    Posts: 2

    Bill Kuran
    Member

    To make it flow twice as well add two superchargers!

    Because I have such a person relationship with my engine, I don't like to say that it is a poor breather. If my kid was born with small lungs I wouldn't say they are a poor breather, instead I would focus on them doing the most with what they have and providing any assistance possible.

    To your question: I think it is difficult to measure the performance difference between heads. Things like compression ratio, chamber shape, chamber volume, spark plug placement, quench area, quench height, transfer area, turbulence, flow velocity, surface temperature, etc. all influence performance. Most of those factors influence the other factors, making if very hard to understand the interactions. Then there is the challenge of trying to detect a small performance (torque) change and being able to, with confidence, attribute it to a specific change/modification.
    One of my favorite videos:

    Engine - Left Side.jpg
     
    Beanscoot likes this.
  8. panheadguy
    Joined: Jan 8, 2005
    Posts: 1,031

    panheadguy
    Member
    from S.E. WI

    Awesome video and engine! Never too much boost? Reminds me of a quote from SLR "It's a misguided devotion to mechanical mayhem"
     

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