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Hot Rods Best breathing flathead 6

Discussion in 'The Hokey Ass Message Board' started by Dave G in Gansevoort, Sep 22, 2021.

  1. Dave G in Gansevoort
    Joined: Mar 28, 2019
    Posts: 1,201

    Dave G in Gansevoort
    Member
    from Upstate NY

    Strange ideas get in my head sometimes. Searched for this but I'm not really good with computers. Some of you may have figured that out by now from the updates on the whatever project thread. You can beat me arouse the ears figuratively if you want, I won't take it personally!

    So I had this thought about flathead 6s. If one was to be modified a little bit, what one would make a decent choice? I would think that if there's one with 12 ports, that are short and not sharper than 90 degrees, that would breathe the best. And as an engine is nothing more than an air pump, and the more air flow through an engine the more power can be made, then the one with the best ports should be able to make the best power.

    So I figured I'd ask for the collective wisdom of the hamb for thoughts on this subject. And like I said I can take it if snide comments need to be made...

    Thanks
     
    THE FRENCHTOWN FLYER likes this.
  2. studebakerjoe
    Joined: Jul 7, 2015
    Posts: 879

    studebakerjoe
    Member

    The Hudson has 12 ports and the valves are canted at an angle towards the cylinders. They also had fairly large valves.
     
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  3. dumprat
    Joined: Dec 27, 2006
    Posts: 3,224

    dumprat
    Member
    from b.c.

    A guy on here got 208hp out of a modified Plymouth 230 flathead six.
     
  4. jimmy six
    Joined: Mar 21, 2006
    Posts: 11,037

    jimmy six
    ALLIANCE MEMBER

    One with a supercharger will breathe well.;)
     

  5. Dave G in Gansevoort
    Joined: Mar 28, 2019
    Posts: 1,201

    Dave G in Gansevoort
    Member
    from Upstate NY

    So thinking back to the early 60's and Joe Messina at Lebanon Valley, the Hudson engines he raced seemed to run good. Hmmm, ok that's the 1st I'll have to check out.
     
  6. studebakerjoe
    Joined: Jul 7, 2015
    Posts: 879

    studebakerjoe
    Member

  7. lippy
    Joined: Sep 27, 2006
    Posts: 6,121

    lippy
    Member
    from Ks

    Chrysler flathead six's were pretty stout on alky with chevy pistons and the block and head milled. :D
     
  8. seb fontana
    Joined: Sep 1, 2005
    Posts: 7,444

    seb fontana
    Member
    from ct

    I read somewhere that Holman Moody built some Ford I6 for boat racing in the early 50's. Don't know HP.
     
  9. $um Fun
    Joined: Dec 13, 2008
    Posts: 617

    $um Fun
    Member
    from Nor Cal

    Holman and Moody was founded in 1957, it might of been Bill Stroppe that was running the Ford team before that on the West coast.
     
  10. Dave G in Gansevoort
    Joined: Mar 28, 2019
    Posts: 1,201

    Dave G in Gansevoort
    Member
    from Upstate NY

    I seem to remember reading in old HR magazines about inline 6s in smaller race boats. That's another area to research. Thanks for kicking the little gray cells into gear...
     
    THE FRENCHTOWN FLYER likes this.
  11. I remember a guy running a chrysler flat six in a circle track car at the old watertown ny fairgrounds speedway, in the early 1960's. The thing was an ok runner against the V8's. The owner put Bob Zeigler in the seat one night( Zeigler was a pretty fair shoe at the time). The damn Mopar lead every lap of that feature that night and won going away. Point being ,a darn good motor even spotting the field 20 cubes. Probably didn't hurt that Zeigler is the all time winningest guy to ever run there, but that little inline sure did sing that night.
     
  12. HAHAHAHAHAHAHAHHA (gasp) AHAHAA HAHAHAHAHAA (tears in eyes) HAHAHAHAHAHA ...
    oh, you are serious o_O

    Isn't that like asking who is the tallest small person o_O


    Kindly disregard the above and carry on ;):p
     
  13. Which flat six came first, Chrysler or Corvair??:rolleyes:
     
  14. Hnstray
    Joined: Aug 23, 2009
    Posts: 12,306

    Hnstray
    ALLIANCE MEMBER
    from Quincy, IL

    Neither….it was the Hall-Scott……;)

    Ray
     
  15. Truckedup
    Joined: Jul 25, 2006
    Posts: 4,430

    Truckedup
    Member

    Smokey Yunick got his start building Nascar Hudson Hornet flathead 6's in the early 1950's. Back then the cars and engines were actual production stock with a bit a cheating when possible...The 308 Hudson 6 with the special factory heavy duty parts and Yunick tuning made about 225 hp..
     
  16. The Hudson in my opinion is your best bet. I do not have any empirical data to support my opinion so it is just opinion.

    Other then the nostalgic value I think it is a total waste of time to build a flathead 6 by the way.
     
  17. Dave G in Gansevoort
    Joined: Mar 28, 2019
    Posts: 1,201

    Dave G in Gansevoort
    Member
    from Upstate NY

    Yes! That's the answer, now what's the question?
     
  18. Dave G in Gansevoort
    Joined: Mar 28, 2019
    Posts: 1,201

    Dave G in Gansevoort
    Member
    from Upstate NY

    Let's say that the effort would be to make something welcome at multiple venues. Same question, except open to ohv 6s.
     
  19. rusty rocket
    Joined: Oct 30, 2011
    Posts: 4,547

    rusty rocket
    Member

    E0AB42F4-B96D-4A8E-AC93-D47ABA8D054D.jpeg 48104CC8-CBB6-4E65-A023-7996166485B3.jpeg
    Hey hey hey there now!! I love my little flat six!
     
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  20. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,613

    Rusty O'Toole
    Member

    Hudson, for the reasons already given.
    A flathead can have as large and well shaped ports as an OHV from the carb to the intake valve seat, and from the exhaust valve seat out the headers.
    It can also have a wider valve chamber than the cylinder, meaning larger valves.
    The restriction is in the sharp turn from the valve area to the cylinder . And the narrowness of the transfer passage. The more open the head, the more room to breathe but the lower compression. This is the compromise that killed the flathead. When low octane gas limited compression to 7.5:1 or less the OHV had little or no performance advantage, and the flathead had several practical advantages like low cost, simplicity, silence, and it was immune to valve interference if you broke a valve spring in other words, the piston could not crash into the valve.
    Example - two American luxury cars got new V8s in 1949. The Cadillac, everyone remembers, and the Lincoln everyone forgets. One OHV, one flathead. Both about the same size, 331 cu in and 337 cu in. Both with 7.5:1 compression. Cadillac 160HP Lincoln 154HP. So a very slight advantage to Cadillac.
    But the Cadillac had to potential of up to 10:1 compression and 250HP which was realized a few years later. Lincoln dropped the flathead for a new OHV after only 3 years.
     
  21. J. A. Miller
    Joined: Dec 30, 2010
    Posts: 1,779

    J. A. Miller
    ALLIANCE MEMBER
    from Central NY

    302 GMC and 300 Fords
     
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  22. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,613

    Rusty O'Toole
    Member

    The real answer to a performance flathead is a centrifugal supercharger as used by Graham and Auburn prewar and Kaiser afterwards. It makes up for the breathing restriction and the lower compression. Graham's blown six made the same HP as their unblown straight eight, and Auburn's blown eight made the same HP as their V12. Kaiser's blown six made the same HP as competitors' OHV V8s. None of these had more than 4 or 5 pounds of boost.
     
    Dave G in Gansevoort likes this.

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