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Flathead Ford block?

Discussion in 'The Hokey Ass Message Board' started by GENERATORSHOVEL, Nov 8, 2008.

  1. GENERATORSHOVEL
    Joined: Dec 12, 2004
    Posts: 27

    GENERATORSHOVEL
    Member

    I have a 46-48 block at the machine shop. I had it hot tanked and checked for cracks. There is a couple small cracks from studs to water jackets, and one very small incomplete crack from a cylinder heading towards the valve seat. The block has 8 sleeves in it. The shop said that it was probably sleeved because of the crack. The shop says that it is a good block and the small crack doesn't matter because of the sleeve. Should I use this block? Does anyone that has built flatheads disagree with the Machine Shop that I am using? Thanks.
     
  2. I think those cracks your talking about are very common and should not hold you back from using the block.
     
  3. Ole don
    Joined: Dec 16, 2005
    Posts: 2,915

    Ole don
    Member

    If you can, show a picture of the cylinder crack on Fordbarn. Those guys have the experience you seek.
     
  4. GENERATORSHOVEL
    Joined: Dec 12, 2004
    Posts: 27

    GENERATORSHOVEL
    Member

    Thanks for the info.
     

  5. power58
    Joined: Sep 7, 2008
    Posts: 432

    power58
    Member

    Every Flathead rebuild / Hot Rodding book I have read says the cracks you describe are expected. Most Experts leave the small cracks alone. I would be very surprized that the block was sleeved for the cracks as it would be ceeper/easier to fix the cracks.
     
  6. Oilcan Harry
    Joined: Mar 3, 2001
    Posts: 906

    Oilcan Harry
    Member
    from INDY

    My block has a repaired crack that ran from a valve and down a cylinder. It is a mass remanufactured engine and all 8 cylinders are sleeved. It was simpler to just sleeve all 8 than pick and fart with different size bores, pistons, and rings. If sleeved correctly [and most pro shops did] there is no reason not to use it. Very common.
     
  7. Assman!
    Joined: May 8, 2007
    Posts: 78

    Assman!
    Member
    from no where

    Your block may have been sleeved from the factory. It was that way on 41/42 blocks for sure. You can ask why but it is fact. Lots of guys used to remove the sleeves and hone to get the extra cubic inches.

    Cracks from the water jacket to the head stud hole are fine. Use thread sealant on the studs when rebuilding and forget about it. As for the crack headed torward the valve seat, you should have the crack drilled and pinned to prevent further creep.

    Daran
    Early Ford V8 Club
    42 Ford Convertible
    42 Ford Coupe
    36 Ford 5W with 8RT Flattie
     
  8. Ol Deuce
    Joined: May 30, 2007
    Posts: 1,188

    Ol Deuce
    Member
    from Mt. U.S.A.

    Assman; what is a 8RT flattie?????? is that a '36 block with LB???????
     
  9. Flat Ernie
    Joined: Jun 5, 2002
    Posts: 8,406

    Flat Ernie
    Tech Editor

    8RT is an 8BA-style truck engine with low-compression heads

    What's the bore of the sleeves? As mentioned, some 221 blocks were sleeved from the factory.

    Cracks - studs to water jacket = no problem. Cylinders to valves = problem. If sleeved correctly, might be OK - depends on the crack. Virtually all cylinder cracks can be repaired by one method or another...
     
  10. Not2low
    Joined: Sep 5, 2007
    Posts: 83

    Not2low
    Member
    from Eaton,Ohio

    I am starting my first flathead rebuild also and found a wealth of info in here by using the search function.Some cracks are normal and will not require repair.Some flatheads were sleeved from the factory and some people prefer the sleeved blocks.You can search and read for hours in here about flatheads.Bruce Lanchaster is a flathead GOD.Look for any post he has written.Good luck with your build.
     
  11. Not2low
    Joined: Sep 5, 2007
    Posts: 83

    Not2low
    Member
    from Eaton,Ohio

    Flat Ernie is another Flathead expert,look for his post also.
     
  12. Welcome to the world of Ford Flat Heads.
     
  13. Flat Ernie
    Joined: Jun 5, 2002
    Posts: 8,406

    Flat Ernie
    Tech Editor

    I'm far from an expert...Bruce, on the other hand, is a walking early Ford encyclopedia! There are several very knoweldgable folks on here...
     
  14. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    The one heading for a valve seat...it's gonna get there eventually, if it hasn't already! Your block should have all 16 hard seats...the one at the crack is going to come loose when the crack arrives, and crack may develop on down into deep recesses beyond fixing.
    My guess is they sleeved a cracked bore, and the crack then continued to propagate.
    Seriously scrutinize it with lots of light, cleaner, and wire brush. Wherever it ends...you want it drilled and pinned by a shop that does pin type repairs, can't think of name of the common brand. Killing it now shouldn't cost much, especially in comparison to fixing it after it goes on across the port into places a mouse couldn't reach.
     
  15. Assman!
    Joined: May 8, 2007
    Posts: 78

    Assman!
    Member
    from no where

    Ol Deuce,
    An 8RT is the designation for a 49-53 Ford Truck motor. For a car it would be 8BA. The specific detail about the "8RT" arrangement in my case is that it is a truck motor so it has the truck water pumps that allow me to install the 8BA style block into a '36 Ford. I could have used the same truck water pumps on an 8BA or an 8RT for the install. The blocks are actually the same if you are starting with a bare block, however the 8RT comes from the factory with an extra compression ring in the pistons, which some may see as a benefit. You also need the truck (8RT) oil pan for this install, along with the adapter plate that comes factory on the back of the 8RT block (starter plate, bolt-on bellhousing, among other names) to mate the 8RT or 8BA to a '36 Ford transmission. The list goes on, but that is the whole 8RT blurb description. Thanks for asking.




     
  16. Vergil
    Joined: Dec 10, 2005
    Posts: 785

    Vergil
    Member

    Lock-n-Stitch has a great product. http://www.locknstitch.com/ The machine shop I take the flatheads to use it. Got their catalog & CD (lock-n-stitch) and was well worth watching the repairs made.

    Vergil
     
  17. Retro Jim
    Joined: May 27, 2007
    Posts: 3,859

    Retro Jim
    Member

    My flathead was sleeved from the factory and came in a flatbead that was used on an apple farm . It is the orginal engine and was never rebuilt or replaced . The owners bought it new . So I am going to use mine with sleeves and I know of many people that have small cracks in theirs too . Almost all flatheads have cracks !!! USE IT !!!!!!
     
  18. blown49
    Joined: Jul 25, 2004
    Posts: 2,212

    blown49
    Member Emeritus

    Follow Bruce Lancaster's advice and repair the crack creeping toward the valve seat.....it'll only get worse as he said. The other cracks were common enough they had part numbers.
     
  19. lonewolf
    Joined: Sep 2, 2006
    Posts: 381

    lonewolf
    Member

    almost all flathead blocks are cracked so much so that ford put part numbers on them in 49 to 53
     
  20. Flatman
    Joined: Dec 20, 2005
    Posts: 1,975

    Flatman
    Member

    Hahahaha... A remark I would have expected from Bruce!:D

    Follow the advice about repairing the crack now, save yourself trouble down the road.

    Flatman
     
  21. There could be any number of reasons why they used sleaves in all 8 cylinders. Listen to Bruce and others when they recommended that you pin/stop the crack heading toward the valve seat. Chances are . . . it is already there and the hard seats make it look like it stopped.

    What worries me is that your machine shop doesn't seem to think they have an issue -- which tells me that they have probably NOT built many flatheads.

    Fix it now and you'll prevent a very expensive future problem. Ask lots of questions about how experienced your machine shop is with these sorts of problems and how many they've fixed before? If they are new to the problem and flatheads in general - take the block to somebody who knows what they're doing, has the tools for doing the work, etc.. Also, you should have the block pressure tested once it is fixed -- to insure that it is correct.
     
  22. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    Original sleeves are totally different from repair sleeves! Ford put very thin steel sleeves into many engines roughly 1939--41 to allow rebuilding by just popping in a new set with a simple hand press. Repair sleeves are thick iron. I don't believe that any original type sleeves were used after WWII.
     

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