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EXTREME - Flathead Ford help needed

Discussion in 'The Hokey Ass Message Board' started by jrblack30, Mar 15, 2008.

  1. I followed up on a tip of a ex sprint car guy stuff was being liquidated. The guy ran sprints from mid 50's till the mid 70's. I went there today and looked over the mountain of stuff that was in the middle of the floor, looking for those on or two pieces that screamed take me home. And I was intriqued by these rods and pistons. A little history first this guy ran flathead ford V8 for a while, switched to flathear ford I6, went to Stude then to Hemis. Now I know a fair bit about flathead ford stuff and don't perclaim to know it all, but these have me very confused.

    First exihibit a JE forged piston, 0.050 over stock on a 21A rod. No problem
    [​IMG]
    Next is where I get lost, on the left is the same as above, but what the hell is that on the right? It is also on a 21A rod, it carries a 3 9/16" bore piston with a HUGE dome.
    [​IMG]
    Close up of piston: Oh and they they are JE pistons also.
    [​IMG]
    of rods:
    [​IMG]
    And then there is this which is also on ford rods: I think this is a I6 rod and piston.
    [​IMG]


    The only thing that I can figuire is that the unknown is for an overhead conversion on a flathead block, buy how can you get that pistons in a flathead block. and what overhead conversion. I don't think they are for Ardun neads.
     
  2. Andy
    Joined: Nov 17, 2002
    Posts: 4,771

    Andy
    Member

    4 cylinder converted to V8 rods?
     
  3. I dont think so, beside there was 4 sets of 8. 3 sets were used and one set of 8 is new as shown.
     
  4. BTT with some better pictures of piston diameter.

    [​IMG]
    [​IMG]
     

  5. Flatdog
    Joined: Jan 31, 2003
    Posts: 1,285

    Flatdog
    Member Emeritus

    I have heard of guys in the old days useing ford full floating rod bearing to solve rod bearing failing problems.
     
  6. In what? The guy also ran alot of Stude motors. Whay would you use a Ford beam and be stuck with the problems with the rod bolts? not to mention a weaker beam than the OEM stude beams.
     
  7. From 56 and up the Stude motor rana 3 9/16 bore but only a 3 1/4 or 3 5/8 stroke. If they used these pistons and rods in the Stude motor I would expect to find the pin location in a different location. Based on the Stude stroke of the crank.
     
  8. Flatdog
    Joined: Jan 31, 2003
    Posts: 1,285

    Flatdog
    Member Emeritus

    Thouse ford rod bolts were not a fault.
     
  9. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    Yes, it is from some early OHV V8 converted. I know early Chevy V8's and Studes were converted, both to Ford rods and to Ford bearings on adaptations of other rods. Pourpose was to get a rod capable of surviving high RPM.
    Early V8 fixed bearing rods failed the basic way many fixed bearing rods fail, according to no less than Smolkey Yunick...rod stretch at point of highest stress (which is normally top of exhaust stroke, NOT power stroke!!) at high RPM ovals the hole, drawing both the bearing insert and the edges of the cap and rod parting line INWARD. Oil gets scraped away and/or bearing halves crawl on top of each other and BANG. Later rods took two paths to viability...they relieved the bearings at parting line so there was some space there, and of course they strengthened the rods there. Early OHV racers first used proven floater tech, nearly immune to that mode of failure, and then stout aluminum rods, less flexible through sheer bulk of metal.
    Ford rods could survive high RPM because the bearing design removed the loads of approaching failure from the rod pretty much...rod had to survive only power stroke loads, something like 1/4 of upward load at high RPM, and of course be strong enough to keep the piston at home at upward strokes WITHOUT the massive lower end load of bearing flex.
    Ford forged-in-place bolt failures are usually a result of overtightening somewhere in the rod's history...why racers insisted on new bearings, because most mechanics in those days tightened by feel.
     
  10. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    PS...I think there is an early tech article in HRM on floater conversion, followed by letters, but I think it was on converting 265 Chevy rods to Ford floater bearings. Early Chevies forced a lot of development suddenly...they were the first OHV's with breathing for high revs, and so brought up lots of problems the early Olds hadn't faced since it didn't get good heads for the first few years.
     
  11. Thanks Bruce,

    From what I have been able to research so far it looks like this is for a Stude conversion. As I said earlier this guy had alot of Stude gear mixed in this stuff. the Stude bore is 3 9/16, the Stude rod is 1/4 in shorter, these pistons have an 1/8 shorter in pin location to piston flat, now add a Stude crank that is 1/8 destroked gring and there you go. Now I have yet to measure up the crank journals and rod end thickness to see if it would work but it sounds as if this was the combo that this sprint car builder was running.

    I am going to have to check this out some more. but it looks like this guy put together a very high compression destroked Stude motor with full floating bearing courtesy of the Ford rods. Looking at the dome on these and having a 3 1/2 or so stroke these motors must have screemed.
     
  12. Dale Fairfax
    Joined: Jan 10, 2006
    Posts: 2,585

    Dale Fairfax
    Member Emeritus

    If your conclusion is correct (and it appears logical) that old guy was doing some really hi tech thinking. He definitely wasn't following the herd.



     
  13. I believe this is definitely a case where he bored a flathead block past the cylinder bore to 3 13/16, then sleeved it back with heavy 1/8" sleeves (welded to the block - top and bottom), then he cut up two Jimmy 6 heads so they could fit on the flathead (welded the crap out of them as well). It was a way to make the flatheads compete against the big 6 Jimmys - bastards that they were. It was a rare and old trick . . . used to do it myself. :D








    Ahhhhhhhhhhhhh . . . just funning yah! Can't say I ever saw a piston like that on a 21A rod. Though I do like those rods - have quite a few sets and have been stocking up on CAD silver bearings recently for a few stroker flatheads - traditional style.
     
  14. Yeah it is for sure an interesting set up this guy was running.
     
  15. Yeah, I have never seen anything like it before either. I have shown three other Flathead builders and one old timer Strint car builder and they havn't seen it before either.

    You like those rods. He has like 20 sets in a big box waiting to be worked up. I may take a few sets but there is now way in hell I could use 20 sets. Maybe if I built a screaming motor once every year, maybe......
     
  16. Bruce Lancaster
    Joined: Oct 9, 2001
    Posts: 21,682

    Bruce Lancaster
    Member Emeritus

    There are lots of people who would help using up your spares! Especially if new...as I said, the bolts can be a danger point if some gorilla overtightened them to the stretch point back in '49, then someone cleaned up the stretch with a die so they look and feel good...
     
  17. Hi: If he has any NEW ones . . . . I'd love to buy a couple sets of 21A rods.
     

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