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Technical Is this a 81A flathead

Discussion in 'The Hokey Ass Message Board' started by dutchrod, Jan 6, 2022.

  1. dutchrod
    Joined: Feb 5, 2009
    Posts: 406

    dutchrod
    Member

    Yesterday I bought this running flathead.
    The seller told it was a industrial engine, I see 81a-6050 on the heads and on the bell only a 8.
    I think I got a 1939 221cui flathead but want to be sure.

    Also I don't see where I can put the oil filter lines , on my 59AB one line goes from the rear of the engine to the filter and the other to the lower side of the engine.
    On this engine I see nothing on the side of the engine and only on the rear.

    Also this flywheel is damaged the they drilled and turned it for a small clutch , I want to replace it.
    I can get a French flathead over here flywheel but a don't know if that wil fit the crank and my new ford 59AB clutch that I have.

    Thanks for the help ,
    Dennis


    IMG_8090.jpeg IMG_8098.jpeg IMG_8097.jpeg IMG_8096.jpeg IMG_8093.jpeg IMG_8092.jpeg
     
  2. millersgarage
    Joined: Jun 23, 2009
    Posts: 2,139

    millersgarage
    Member

    never heard of an 81A designation. Looks like a basic flatty

    Wonder why the offset genrator?

    I have seen oil return lines in the pan, or dipstick boss
     
  3. alchemy
    Joined: Sep 27, 2002
    Posts: 17,926

    alchemy
    Member

    I can see the bulges on the sides of the pan rails, so that means there were the freeze plugs in the rails. Built like that from the first of the 24 studs to approx '40 or '41.

    If you look on the front of the block, right above the front cover, you can see the face of the block has a sharp corner as if you could rest a pencil there. This is known as the "pencil test", showing an early 24 stud block, but I forget which year that area changed.

    The 8 on the bellhousing isn't a common designation, and is probably just a random casting marker from that particular run.

    The 81 designation means the heads were designed in 1938. Maybe still produced, unchanged, into later years though.

    The dual belts makes the industrial heritage seem logical.
     
    Hamtown Al and Carter like this.
  4. Glenn Thoreson
    Joined: Aug 13, 2010
    Posts: 501

    Glenn Thoreson
    ALLIANCE MEMBER
    from SW Wyoming

    You can buy the pan fitting for the oil filter return tube from Macs, I think. Another alternative is to drill and tap a hole for 1/8" pipe thread in the intake manifold, between the rear most intake runner and the fuel pump stand. Install a flare fitting for a quarter inch tube and run a line from the oil filter. The return oil will go into the lifter valley and back to the pan. The reason for the offset generator could be because they didn't have the manifold mount bracket. (?) The 81-A on the head is a part number and I may be able to find a year and application for you. This could be a truck engine, maybe a WWll left over.
     

  5. Ralphies54
    Joined: Dec 18, 2009
    Posts: 758

    Ralphies54
    Member

    I know very little about flatheads, is that an aluminum block??
     
  6. Those heads belong on a 239 but not sure if they fit a 221 as well. May have to take a head off to confirm 221 or 239.
    If it's a 239, good score. May also be a relieved block as well>
     
    Last edited: Jan 7, 2022
    Hamtown Al likes this.
  7. dutchrod
    Joined: Feb 5, 2009
    Posts: 406

    dutchrod
    Member

    Thanks for all the feedback.
    the offset generator was put on later by the previous owner.
    I’m gonna pull the heads next week to be sure what i got.

    learning something new everytime !
    I have a french flatty in my roadster and a 59 ab in my 46 fordor.
    And now this one , they are all a bit different.
     
  8. Glenn Thoreson
    Joined: Aug 13, 2010
    Posts: 501

    Glenn Thoreson
    ALLIANCE MEMBER
    from SW Wyoming

    Thus sayeth the Green Bible: 81 A heads -- '38 -'42 passenger, commercial and 122" truck with domed pistons. Almost certainly 221 cu. in. (small journal) with factory sleeved cylinders. Too bad you're so far away. I have some engine parts for this one. I do have something that's not being produced and can be mailed, though. Head gaskets for the 221 with sleeves. The gaskets fit exactly on the top of the sleeves and prevent them from climbing up.Won't work for a bored engine. There are simple modifications to the cylinder heads you can do yourself to improve cooling. If you have the heads off and want to do them leave me a private message and I'll describe them for you. Don't pay too much attention to most numbers on these engines. Most don't mean anything but to those long gone factory workers. Some were never recorded and some mean nothing to anyone.
     
  9. clem
    Joined: Dec 20, 2006
    Posts: 3,632

    clem
    Member

    Is that a generator or one of those British dynamators ?
    Also, why no fan - or was it removed ?
     
  10. Fortunateson
    Joined: Apr 30, 2012
    Posts: 4,546

    Fortunateson
    Member

    X2 on whether or not the block is Aluminium...
     
  11. youngrodder1929
    Joined: May 28, 2006
    Posts: 430

    youngrodder1929
    Member
    from Vancouver

    81a is 221ci part number designation 99a is 239 ci
     
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  12. dutchrod
    Joined: Feb 5, 2009
    Posts: 406

    dutchrod
    Member

    Engine is not aluminum, just a strange color.
    I’m gonna clean the engine and paint it ford green.
     
  13. dutchrod
    Joined: Feb 5, 2009
    Posts: 406

    dutchrod
    Member

    The generator was later put on , i plan on normal style generator with fan.
     
    clem likes this.
  14. dutchrod
    Joined: Feb 5, 2009
    Posts: 406

    dutchrod
    Member

    Also there are two taps for coolant on each side of the engine just behind the waterpumps , first time i see this on a flathead.

    F413A122-691A-450D-AF41-7D787FC02A43.jpeg
     
  15. dutchrod
    Joined: Feb 5, 2009
    Posts: 406

    dutchrod
    Member

    Made a simple engine cradle today so i can pull the pan and check if i can save the flywheel or if it is junk.
    They drilled extra holes in it for a strange small clutch.
    Also it looks like it was on a lathe but not evenly turned, one side has a deep edge and the other side is flat.

    9F39A577-5789-4303-9FA6-900A4A6DE04C.jpeg 76512353-9BC8-4144-88CC-5D25CF88DDFE.jpeg 8002066C-F178-45CD-BB25-964B99B5F318.jpeg
     
  16. Beanscoot
    Joined: May 14, 2008
    Posts: 2,356

    Beanscoot
    Member

    The upper nut is upside down.

    [​IMG]
     
    rusty valley and Hamtown Al like this.
  17. flatjack
    Joined: Feb 13, 2007
    Posts: 948

    flatjack
    Member

    Oil filters were accessories on these engines and the oil was returned via a hollow bolt on the fuel pump stand.
     
  18. alchemy
    Joined: Sep 27, 2002
    Posts: 17,926

    alchemy
    Member

    The flywheels of that era (on passenger cars) had a big raised edge outside the clutch disk. It's common to cut it off to lighten them. Maybe this was done for the industrial application.
     
  19. clem
    Joined: Dec 20, 2006
    Posts: 3,632

    clem
    Member

    did Henry Ford ever build an aluminium block, - I never thought so - not in mass production anyway.
    So google turned up this……..may be of interest to some.
    Sorry if this appears to be a distraction to this thread, - happy to remove post if required.
    https://www.fordbarn.com/forum/showthread.php?t=95539
     
    Last edited: Jan 8, 2022

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