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Trash or fixable?

Discussion in 'The Hokey Ass Message Board' started by jefscoupe, Aug 21, 2013.

  1. jefscoupe
    Joined: Apr 19, 2006
    Posts: 294

    jefscoupe
    Member

    It could probably be welded, or does if need to be?
    [​IMG]

    Just to be clear, I'm talking about the gouge at the edge of the journal.
    It's a 4" stroke Merc crank and I've already been through h and high water.
    I plan on a fairly warmed up street motor.
    Suggestions?
     
  2. Wildbill29tudor
    Joined: Apr 16, 2013
    Posts: 460

    Wildbill29tudor
    Member

    Im sure it has thrown it out of balance, but I would have a machine shop check it out. Is it cast or forged? If its cast it's probably junk now, I know forged cranks can be welded on


    Posted using the Full Custom H.A.M.B. App!
     
  3. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    My gut reaction is yes, it needs to be repaired, could cause low oil pressure on that journal pair.

    FWIW, a cast Scat crank is around $700. I could see that damage being a fairly expensive fix...
     
  4. stimpy
    Joined: Apr 16, 2006
    Posts: 3,547

    stimpy

    Cast can be material added by plasma spray welding or immersion welding , its expensive and your going to have to have it straightened and stress relieving after the welding is done . it will hold up to a stock build but if your going to push it , it will fail . so cost will be a issue . look for a industrial crank or machine company that does it .
     
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  5. nexxussian
    Joined: Mar 14, 2007
    Posts: 3,231

    nexxussian
    Member

    As much as I love to save old iron, that picture screams "doorstop" to me. :(

    As others have mentioned the Scat cranks aren't all that expensive, so while it's worth it to have a crank shop look at it, be prepared for it to be cheaper to replace than fix. :(

    For clarity, I expect if one journal looks like that, the others will likely need work. :(
     
  6. Jay Tyrrell
    Joined: Dec 9, 2007
    Posts: 1,631

    Jay Tyrrell
    Member

    That sir is risky. I would source another one. How hard are they to come by? I have seen where repairs were made and all is good until you start seeing those Christmas sparkles in the oil when you change it. Think about the dollars that you are planning on throwing at the motor rebuild. It would all be a waste if the crank starts flaking.
    Jay
     
  7. big M
    Joined: Mar 22, 2010
    Posts: 709

    big M
    Member

    I've got a notion that it will be more cost effective to replace it, and use that one for a mailbox post.

    ---John
     
  8. Not a authority on this type of problem but if were me I would be looking for a replacement,,I would be horrible to build the engine and have the repair let go and rear it's ugly head. HRP
     
  9. 1964countrysedan
    Joined: Apr 14, 2011
    Posts: 1,131

    1964countrysedan
    Member
    from Texas

    I don't know the rarity or the value, but if it is forged you can maybe have it repaired for just under a grand, assuming you find a sure enough qualified shop. I personally would not use it but then again I have been getting paid the past few months to ensure crankshafts are safe at 20,000+ feet, so I might be a little picky.
     
  10. kwoodyh
    Joined: Apr 11, 2006
    Posts: 642

    kwoodyh
    Member

    Weld it up, turn it down and run with it!
     
  11. I've seen merc cranks go for 2-400.
     
  12. jefscoupe
    Joined: Apr 19, 2006
    Posts: 294

    jefscoupe
    Member

    Well I bought this Merc engine for 200 bucks and I was hoping to at least save the crank. Little else was much use. It threw a rod, busted the cam into 4 pieces and knocked a hole in the block. Didn't know until I got inside of it.
    How do you tell if it's cast or forged? Same as you would a SBC? I thought all Merc cranks were forged.
    But I'm still learning about flatheads. I have a Ford engine that's in good shape...so far.
     
  13. cmyhtrod
    Joined: Nov 29, 2008
    Posts: 360

    cmyhtrod
    Member
    from ct

    With my luck?

    I'd junk it
     
  14. Nailhead dodge roadster
    Joined: Jun 28, 2004
    Posts: 707

    Nailhead dodge roadster
    Member
    from Cheney Wa

    Can be fixed by a competent machine shop....if its something you want to build an engine around, now would be a good time to have it fixed and offset ground. a 4in bore and a 4-1/8 stroke crank would give you a sweet 296 Flatty.
     
    Last edited: Aug 21, 2013
  15. Do you have a hammer?
    Hit it, if it rings it is forged, a dull sound, it is cast.
    Follow the casting line, if it is straight, its cast, it it turns
    at the weights and journals then it is forged.
    while your welding the side of the journal, you might as well do the journal as it looks like it needs a .030 to .040 cut to clean. Which takes off any surface hardening....
    I would say between $800 to 1k to weld, machine and balance.....
     
  16. I think I'd buy me three or four more $200 motors first. They can't all be junk inside.
     
  17. jesse1980
    Joined: Aug 25, 2010
    Posts: 1,356

    jesse1980
    Member

    Depends on what kind of crank it is. If its like a 350 Chevy crank scrap it, their a dime a dozen. If its something really hard to find, try to fix it.
     
  18. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    This is exactly what I was thinking. With the Scat cranks going for $700, I would really think about that. Is the cast steel Scat crank "better" than a repaired forged steel stocker? Debatable. Is it going to be cheaper than repairing this crank? In all likelyhood, Yes.
     
  19. jefscoupe
    Joined: Apr 19, 2006
    Posts: 294

    jefscoupe
    Member

    Sorry, this is a 52 Merc flathead crank. Stock journals.
    That one throw is the only one hurt.
    And $200 flatheads are not easy to find. For me anyway.
     
  20. porknbeaner
    Joined: Sep 12, 2003
    Posts: 41,063

    porknbeaner
    Member

    Lets start with two obvious observations here. Number one is that the Merc crank is a steel crank and number two there is no way in hell that a flatty can be built to to put enough pressure on the lower end to make repairing the crank an iffy situation if you take it to a pro.

    here is how the repair will be done, the entire journal will be welded up and re-cut. just like building a stroker crank used to be done prior to 1-800 hot rod.

    Now here is something that no one has ouched on, is the crank just chipped or is it broken @ that journal, if it is cracked either part or all the way through it is a repair that is not going to happen.

    Before we decide by looking at a photo if the repair can be made the crank needs to be maganafluxed and then an estimate to make the repair needs to be made by the shop that will be doing the work. Then calling for a price on a replacement crank can be made and a legit informed decision can be made.
     
  21. Dale Fairfax
    Joined: Jan 10, 2006
    Posts: 2,586

    Dale Fairfax
    Member Emeritus

    Forged steel crankshafts in Flathead Fords were phased out in 1935. Cast cranks were intro'd in 1933 and were used simultaneously with the steel cranks thru 1935. After '35 they were all cast. Did you ever see that big chip out of the side of a counterweight? That's where a riser was knock off with a big hammer. Forged cranks are made in a flat configuration, TRIMMED in a die, then twisted while at forging temperature.

    Having said all that, it's obvious that cast cranks can be and have been welded. Where do you suppose all those extreme strokers of the early '50s came from? They were welded and reground.

    Suggest everybody flip over to the Ford Barn where this poster raised the same question. Check out Walt DuPont's response.
     
  22. I'm with Porknbeaner on this one. Definitely have the crank magnafluxed before you do anything else. It looks to these old eyes like it spun a bearing on that journal.
     
  23. jefscoupe
    Joined: Apr 19, 2006
    Posts: 294

    jefscoupe
    Member

    Yes, I'm on the Ford Barn too. It looked like it spun the #1 rod bearing then threw the rod cap (from the looks of them, it stacked the inserts). The crank then came around and caught the rod.
    I think that's what knocked the piece off the side of that journal.

    [​IMG]

    [​IMG]

    These are also posted in my build post linked below. (pg 5 post #99) I figured I'd get quicker response time with a new post on this. And I did.

    I am amazed at how many on the HAMB would write this crank off so quickly.
    That could be my fault for not specifying this to be a flathead crank in the beginning. Though I did say it was a Merc 4" stroke crank.
    If it was a SBC crank? Sure, no question. I could find one of those easily and for cheap.
    I believe the journal could be turned (ground) and cleaned up. Might take max to do it though. And yes I would get it checked out by a pro. Just thought I'd run it by a few folks and see what y'all thought first.
    If HP was all I was looking for, I'd put a SBC in it and be done. But that's not what I want.
    I think I'll back burner the engine build for a while and see what turns up.
    I've got plenty of other stuff to do before it needs an engine. I can go ahead and get the mounts made...again.
    Thanks for all the input.
     
  24. If it's a rare Bugatti or other European exotic, sure.......give it a fix.
    If it's an old common vintage American crank, shove into the dumpster!
     
  25. rpu28
    Joined: Jan 17, 2006
    Posts: 105

    rpu28
    Member
    from Austin

    Looks like it's easily salvageable, especially given that the weldment is not in a high-stress area. It's not like you're trying to weld that connecting rod back together.

    Clean the area where you're going to add metal, and you might drill or grind in a few negative edges to cage the weldment. TIG weld with nickel rod a little at a time (it flows well and is more flexible than cast iron) and peen the weldment with a low-radius pick (i.e. not sharp, but not fat) immediately. Then have the whole crank Magnafluxed before turning it.
     
  26. jefscoupe
    Joined: Apr 19, 2006
    Posts: 294

    jefscoupe
    Member

    Oh yeah, I pass by these cranks just lying on the side of the road everyday...People asking me all the time: Hey! You want an old Mercury flathead crankshaft? You can have all of them, just get them out of my yard.
    Oh, and you can have that old Bug back there too. Bug-aty or some such foreign car. Silly thing looks like it's riveted together down the middle. :D
     
  27. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    Whether or not its fixable isn't really the question, theres no doubt it can be repaired. The question is, is it cost-effective? If you are so dedicated to being period correct that you dont want to use a modern crank (and I "get" that, I really do) just be prepared for the fact that 1) your local engine rebuilder hack shop is not gonna do this, and 2) when you DO find someone to do it, that $700 scat crank is suddenly gonna look like a deal.

    P&B also made a valid point, theres an EXCELLENT possibility that this crank is cracked. I didnt mention it because I just take it for granted that any internal engine part that has suffered impact damage should be crack checked before further use. And as someone else has mentioned, that journal is also fragged.
     
  28. sunbeam
    Joined: Oct 22, 2010
    Posts: 4,287

    sunbeam
    Member

    I bet you can get it fixed for 1/2 the price of a SCAT crank. If you buy a Chinese crank check it close and have it balanced is a must.
     
  29. falcongeorge
    Joined: Aug 26, 2010
    Posts: 18,341

    falcongeorge
    Member
    from BC

    I agree with this part, the first part, well, not so much. I recently looked into welding a rod journal.$$ and this repair is more labour intensive...
     
  30. mustang6147
    Joined: Feb 26, 2010
    Posts: 1,847

    mustang6147
    Member
    from Kent, Ohio

    I would say, this is a question for a machine shop. I know they weld axles, and my opinion is if it will hold an axle, I would think it could be fixed.

    I think availability and cost will also factor in.....

    You may look on the thread here about the crusher.... SInce there are cars going to the crusher out west, you may find one there..... Just a thought
     

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