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History What are the two bulges on the ends of my 81T flathead heads ?

Discussion in 'The Hokey Ass Message Board' started by 34 GAZ, Jan 26, 2019.

  1. I just bought this real nice pair of steel Ford 81T heads. LH & RH. Made in U.S.A. I believe from a 1938 truck engine. What are the big bulges on both ends ? Never seen that before:confused: . I suppose you could drill and tap for heater hoses but that is allready next to the radiator hose position. Then again they make it easy to remove the heads , a claw hammer, big chissel or small crowbar fit under them real easy o_O. Any ideas ? G.JPG H.JPG I.JPG
    Last edited: Jan 26, 2019
    Deuces likes this.
  2. And what is the purpose of the threaded outlet? Possibly marine use or industrial?

  3. I have not seen the cast bulges before. I would have guessed that the heads are aftermarket, but they are marked "Ford". Perhaps they were for some industrial or marine application.
  4. The bulges are probably for machining fixtures and I have no idea why the water outlets are threaded. I mean I know what I just don't know what the application is.
    LOU WELLS and BigO like this.

  5. williebill
    Joined: Mar 1, 2004
    Posts: 2,706


    " Call for Mr. Lancaster !"
  6. Deuces
    Joined: Nov 3, 2009
    Posts: 19,740

    from Michigan

    I'm thinking "chills" from the casting process that never got ground down.....
  7. No mate, they are semi hollow, still thick enough to allow drilling/tapping a thread.
    Deuces likes this.
  8. Flathead Dave
    Joined: Mar 21, 2014
    Posts: 3,228

    Flathead Dave
    from So. Cal.

    Might be horny little heads...
    Boden, Deuces, BigO and 1 other person like this.
  9. KoolKat-57
    Joined: Feb 22, 2010
    Posts: 3,027

    from Dublin, OH

    Maybe a Posting over on the Ford Barn site will get an answer.
    Just a thought.
    Deuces likes this.
  10. If you do post it there and get an answer please respond back here.
    Hnstray, Deuces and BigO like this.
  11. Maybe they're speed bumps. :D
    spurgeonforge, Deuces and BigO like this.
  12. firingorder1
    Joined: Dec 15, 2006
    Posts: 2,147


    Maybe they're glad to see you.
    XXL__, Deuces and BigO like this.
  13. Maybe they're glad to see you 4 times, ever think of that ? Hahaha
    Deuces likes this.
  14. Seriously, if you find a real answer please let us know. BigO
    Deuces likes this.
  15. 4dFord/SC
    Joined: Sep 12, 2004
    Posts: 837


    When they're good, they're good, but when they're bad, they're even better;)
    Deuces likes this.
  16. BJR
    Joined: Mar 11, 2005
    Posts: 6,804


    Don't those bulges go over the water passages that need to be plugged when running newer heads on the older blocks, or the other way around?
    stillrunners likes this.
  17. Not a bad thought BJR, i guess i should compare a few head gaskets i have upstairs in the attic.
    Deuces and Atwater Mike like this.
  18. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    C81T is Canadian and quite consistent with early WWII use. Ford Canada wasa a BIG supplier of Ford trucksm Bren carriers, engines for fire fighting pumps, and MANY etceteras for England and the whole commonwealth. in '42-3 or around there this head would, I think, have gone out of production as the 1942 type 221's and 239's from Canada replaced the earlier series in all applications.
    This one looks to have had some sort of odd, possibly armor application...
  19. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    I can't tell if outlet is threaded or simply has grooves to give better grip to the hose and clamp. Whatever, someone did not want to see the hose popping off! The bulges look like something to allow coupling engines. I have ssn those on the 1937 21 studs that England used right through the war...Ford Canada was a MUCH bigger supplier to England that Ford England was.
    Trucks and such used perfectly normal flatheads, Bren Carriers got more mods for an engine that had to run full blast inside an armored box...I don't have full documentation on those.
    Many British apps had full flow filters and/or coolers using blocks with 3 ports at rear.
    Less normal uses were plentiful...flatheads supplied the electrical power for huge spotlights mounted on B-24s to illuminate the final attack of surfaced U boats at night, for instance, and moved all sorts of pumps and generators used during the blitz.
    The early war Matilda I tank used 2 flatheads, maybe with couple water systems?? Not any info on those in my basement. Anyway, wartime flateads supplied power for all sorts of wartime contraptions. I doubt those heads were made for civilian use.
  20. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    Also...C81 is a Canadian number, but I just saw the Ford USA casting at bottom! I think head was for sure made for Canadian use...Ford USA definitely diverted engines North any time Ford Canada got behind. That need for interchangeability is why our engines from mid-war until the end of the flathead have the little flat boss at back making 3-port machining easier. Canada went to full-flow outlet back there during the war, and presumably requested the mod on USA blocks to keep everything interchangeable. Ford Canada in turn modified some of its parts to interchange with Ford England model 77's
  21. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    General correction...Matilda I tank used ONE model 77E Ford V8, mot two. The Matilda II, which has nothing much in common with the I, used TWO much larger bus engines.
    SOMETHING english used two 77's...some were spotted in the 1970s when tons of WWII British Ford stuff was pouring into Joblot Automotive and I was a starving student able to buy nothing!
  22. I have a C81A head with the same configuration. Came off a '39 Mercury 99 "keystone" block. I assumed the bulges were to whack on with a brass hammer when you need to get the head off! Coolant outlet is the same as well. Assumed it is for better grip/sealing of the hose.
  23. PS. The block referenced in my previous post was Canadian built.
  24. texasred
    Joined: Dec 3, 2008
    Posts: 1,091

    from Houston

    They got wood sitting next to a sbc
  25. Bruce, thanks a million for your answers . Sometimes you hear of people building a project around a part they had laying around. Well i don,t think i will be building a WWII tank :D:eek::rolleyes:o_O around these heads.
    Deuces likes this.
  26. Interesting Glen. I found these heads at a small club swapmeet last week. Whats more interesting is i had just started cleaning up my 99A Mercury ( keystone ) engine that i bought a good 5 or 6 years earlier . That engine had mismatched and not correct heads. ( see my recent thread on the 99A ) Seems my 99A is Canadian as it has that 1 external hole in the lower right corner next to the waterpump. ( between the pump and the end of the crankshaft )
    Deuces and warhorseracing like this.
  27. s55mercury66
    Joined: Jul 6, 2009
    Posts: 3,980

    from SW Wyoming

    Could they merely be attachment points? They look like a pretty handy place to lift from, with a sling on each side, or one at the front, and one at the rear.
    Deuces likes this.
  28. Budget36
    Joined: Nov 29, 2014
    Posts: 5,838


    Them heads aren't that heavy...not like ya pulling up a BBC or Hemi head. Has to be a reason tho, some government spec for?????
    Deuces likes this.
  29. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    The bulges are at an angle to axis of engine, so maybe not useful for adding stuff to drive...and have nothing to do with normal cooling system at all...I think they have to be provisions for sending hot water somewhere, perhaps to a heating system or to hook up two engines into a single cooling system. Tanks needed heaters in northern Europe.
    And remember, flatheads powered all sorts of military stuff, and most of that is pretty much undocumented!
    Moriarity, Deuces and kidcampbell71 like this.
  30. Why not?:rolleyes: Have you ever been in an armored tracked vehicle?:confused: Everyone will move out of your way on public roads:oops: and some will even be envious.:eek: Those heads would have more heater attachment points and you could put multiple heaters in the tank. I have been in an M3A3 Bradley in -40 F before wind chill and we froze our a$$eS off with the Diesel powered heater. Hot water heat would have been welcomed.
    Deuces likes this.

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