Register now to get rid of these ads!

  1. Hey Fellas, excuse the spam... But, we've got some new swag in the store! In fact, we've got a real rarity - H.A.M.B. Drags Merch!!! Hats, shirts, key fobs, the works... To check it out, just head on over to our store. CLICK HERE!
    Dismiss Notice

Flatheads 101: 21 Vs. 24-Stud

Discussion in 'The Hokey Ass Message Board' started by Ryan, Oct 25, 2007.

  1. Ryan
    Joined: Jan 2, 1995
    Posts: 16,969

    from Austin, TX
    Staff Member

  2. THANKS RYAN!! as a new comer to the flathead scene i still have many questions! and that was one of them-thats why i love the HAMB
  3. Magneto349
    Joined: Oct 22, 2007
    Posts: 35


    Sweet! Another thing to put in my flathead notebook! Thank You!
  4. Retroharley
    Joined: Jan 3, 2007
    Posts: 123


    I never knew that. Thanks for sharing. Now I'm going to always clance at the center studs when I see a flathead engine.
    Register now to get rid of these ads!

  5. skajaquada
    Joined: Sep 14, 2004
    Posts: 1,642

    from SLC Utard

    i always thought it was the waterneck location that gave them away...?
  6. srosa707
    Joined: Jun 5, 2005
    Posts: 1,551

    from Sacramento

    Thanks for clarifying.
  7. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 20,767

    Bruce Lancaster

    They came both ways on 21's...
    Probable reason for change: 21 had a stud directly below centers of bores, and boring to 3 3/16 left only a scary amount of iron between stud and bore.
    I think they changed the tooling in preparation for the intro of the bigger bore engines to keep tooling as common as possible between 221 and 239.
    Joined: Nov 13, 2002
    Posts: 923


    Hey Ryan that is just great info.Just two days ago I was looking at a flat head and counting the studs.It will be easy now Thanks!
  9. pasadenahotrod
    Joined: Feb 13, 2007
    Posts: 11,757

    from Texas

    32-36 21s had water pumps in the heads.
    37-38 21s had water pumps in front of block like 38-53 24s.

    That stud line is a great tip to identify the stud count. Thansk for the tip.
  10. continentaljohn
    Joined: Jul 24, 2002
    Posts: 3,480


    21 stud/bolt hard to find speed parts and very expensive (Arm &Leg ) Were the 24 stud/bolt speed goodies are abundant and in a reasonable price range. The 24's also offer a much wider range of speed accessories.
  11. SlamCouver
    Joined: Jun 26, 2006
    Posts: 2,002

    from Brazil, IL

    Awesome bit of info, if you remember other tricks let us know! i require tricks and tips.
  12. Lil' Lance
    Joined: Nov 3, 2006
    Posts: 99

    Lil' Lance

    thats a good way to look to tell the difference. i always before just looked at the bottom of the head. 2 bolts below the bore=24stud, 1 bolt below bore=21 stud. but cool hey either way works!
  13. 36Brua
    Joined: Jul 31, 2007
    Posts: 88


    Does it hold true a 21 stud head has 5 studs across bottom of head vs 8 on a 24 stud? xYz
  14. Rand Man
    Joined: Aug 23, 2004
    Posts: 2,929

    Rand Man

    . . . waterneck location that gave them away...?

    No the 59A series (center) and the later 8BA series (front water neck) both have 24 studs (or bolt holes).
    Joined: May 13, 2002
    Posts: 3,258


    That's how I tell at a glance.
    and the 5 are wide spaced,can spot it across the parking lot.
  16. Very interesting.

    Just wanted to throw in another interesting flattie into the mix. This is an aircooled prototype that is in Speedy Bill's museum (that place is worthy of its own feature sometime).

    Thanks for the info Ryan.

    Attached Files:

  17. synthsis
    Joined: Mar 29, 2006
    Posts: 1,899


    just more info for me to absorb. thanks for the write-up!
  18. 1950ChevySuburban
    Joined: Dec 20, 2006
    Posts: 6,210

    Member Emeritus
    from Tucson AZ

    I like that little trivia stuff!
  19. Old Roadster
    Joined: Jul 2, 2006
    Posts: 613

    Old Roadster

    Good Stuff.......
  20. Cyclone Kevin
    Joined: Apr 15, 2002
    Posts: 3,104

    Cyclone Kevin
    Alliance Vendor

    If there was a market that could support this type of 21 stud venture, I'd continue with it. Tooling alone is close to $11.5 K up front.
    Then you still gotta get the casting done,and machine em up. Are HAMBers game to buy if I were to take this chance.
    They'd be in the same price range as the Flatty Caddy's.
    If you need em. Let see what we can make?
  21. Noland
    Joined: Oct 16, 2007
    Posts: 1,237



    I always wondered
  22. continentaljohn
    Joined: Jul 24, 2002
    Posts: 3,480


    Kevin, I don't even see many in the cars anymore. Most seem to have been replace with modern iron. I would like to put one together in the future. Keep us in mind for some goodies...
  23. Have you noticed the date on this thread?

Share This Page

Register now to get rid of these ads!


Copyright © 1995-2013 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.