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401 Buick cracked block: What to do??

Discussion in 'The Hokey Ass Message Board' started by 49coupe, Jul 7, 2008.

  1. 49coupe
    Joined: Nov 4, 2005
    Posts: 565


    You always get a project that fights you all the way. Well after my waterpump, balancing and transmission issues we hit the granddaddy stumbling block. I got a call from the guy who's rebuilding my 401 and he says they left water in it. The result: a 6" crack at the back of the motor. BTW, its a complete, clean, original low mile motor...F*&k...

    He says it's going to cost $500-600 minimum to fix it at a machine shop. He's recommending getting another block.

    I'm just wondering what your experiences have been with fixing cracked blocks since 401's are not easy and cheap to find anymore. (Unless someone in Ontario, Michigan or NY has one for sale....:rolleyes:)
  2. 1/2done
    Joined: Oct 29, 2006
    Posts: 618

    from Ohio

    Sounds to me like it shouldn't cost you shit. They're the ones with the $600.00 problem.
    kidcampbell71 and MO54Frank like this.
    Joined: May 1, 2006
    Posts: 345


  4. Pothole 31A
    Joined: Dec 15, 2007
    Posts: 318

    Pothole 31A

    I agree with 1/2done it was not your fault that it happend. They is the key word if they messed it up its on them. I paid for a belt for my lawn mower they gave me the wrong one then wanted to charge me again for the right one. I said if you would have given me the right one in the first place i would not be here so give me what i had originally paid for.... and i got it.

  5. 49coupe
    Joined: Nov 4, 2005
    Posts: 565


    Sorry guys, I'm so pissed I can't type. I meant to say that they said someone (not me) left water in the block. I just brought him the motor on the weekend, so he didn't crack it.
  6. Mr48chev
    Joined: Dec 28, 2007
    Posts: 28,358


    I'd hunt another block. File that one under shit happens and go on. You might spend a couple of hundred on another block but you would have the peace of mind of having a block that wasn't patched.
    bill gruendeman and dirt t like this.
  7. Babyearl
    Joined: May 23, 2008
    Posts: 610


    Bummer deal,, not knowing just exactly where it is cracked, it can be repaired with the tapered threaded plug route or welded. I would use the tapered plug fix myself. I don't think it should cost much more than a couple hundred,, but I'm so out of touch I could be all wrong. If you decide to weld it, that could end up a never ending crack.
  8. Wild Turkey
    Joined: Oct 17, 2005
    Posts: 902

    Wild Turkey

    Take it to a real welder and let him look at it. Listen to how he thinks it could be welded, and pay attention to what he says about pre and post heat, etc.

    If he doesn't talk about heating the block before welding, ask him why and go from there.

    My dad welded a hole in a Stovebolt and it ran for many more miles. It can be done, but the welder has to know what he's doing.

    If it's in a low-stress area I'd go for the welding, but I haven't seen the block and am no way an expert.

    Good luck!
  9. AHotRod
    Joined: Jul 27, 2001
    Posts: 11,261


    Start looking for another block

  10. Lock-N-Stitch works extremely well, but it's very labor intensive. I'd bet the bulk of the $600 is labor. It's not a repair for the inexperienced. If your not careful, you can destroy an otherwise repairable block.
  11. Robert gilbert
    Joined: Dec 28, 2007
    Posts: 927

    Robert gilbert
    from boston

    my freind has one in boston its a 61 401 nailhead and tranny pm me if your interested i think he wants $700 for the hole thing . I will take it apart and ship or ship the whole thing .
  12. RichFox
    Joined: Dec 3, 2006
    Posts: 9,989


    If it's a crack in the outer water jacket I would think about brazing it togeather. I'm going to try it on my Dodge Bros four. brazed cast iron before and it seems to work OK.
  13. Revhead
    Joined: Mar 19, 2001
    Posts: 3,027

    from Dallas, TX

    Our 364 was cracked on the ouside water jacked between freeze plugs. We opted to find another nailhead and came across a running, somewhat rebuilt, 425 for $500.

    I also recently saw this
  14. Shifty Shifterton
    Joined: Oct 1, 2006
    Posts: 4,964

    Shifty Shifterton

    Even with the current cost of 401s, that's a replace rather than repair. This is coming from a foundryman. Block sees a lot of stress, moves around a lot more than you probably think, and will knock the bottom out of your wallet if it fails after rebuild.

    Ahotrod's comment is right on. It probably can be fixed and might even go the distance. But should ya......
  15. Tsquared
    Joined: Feb 5, 2005
    Posts: 522

    from Pratt, Ks.

    I`ll second that!!!
  16. Shifty Shifterton
    Joined: Oct 1, 2006
    Posts: 4,964

    Shifty Shifterton

    Oh yeah, here's the other thing. When it cracks one place it moves in other places if there's any gap in the crack. Now in addition to the risk of a hidden crack elsewhere, you have the issue of dimensional movement of machined surfaces.

    If I had a dollar for every casting my employers have sold at a loss because of snowballing weld repair, I might actually have enough money to buy some of their assets at the liquidation auction.
  17. Joe G
    Joined: Apr 2, 2008
    Posts: 83

    Joe G
    from Minnesota

    I just picked up a good 401 core for $400. Got it from my favorite junkyard, French Lake Auto Parts in Annandale, MN.

    Unfortunately, shipping one to Toronto from here would probably cost another $400. Call around, you should be able to find a good block for less money than it would cost to repair yours.

    Good Luck!
    kidcampbell71 likes this.
  18. Jeff Norwell
    Joined: Aug 20, 2003
    Posts: 13,176

    Jeff Norwell
    Staff Member

    If your from the Toronto area.... look up Gary Weldon...... he may help ya out.....a VERY big nailhead guru.......
    I would look for another block.....
    kidcampbell71 likes this.
  19. Mooosman
    Joined: Sep 3, 2006
    Posts: 115


    Find a machine/welding shop that works with large diesel blocks/industrial equipment. The large Cat/Cummins/Detroit blocks are hugely expensive to replace, so these shops are very good at repairing almost ANY kind of damage. I have seen them fix windowed blocks with a hole the size of a softball in the side of the block.

    They will be able to weld it up so nice you'll really have to look to see where the crack was. If done properly, it will be just as strong as the original iron.

  20. oilslinger53
    Joined: Apr 17, 2007
    Posts: 2,500

    from covina CA

    i read once on a tube od J B weld that a farmer in minnesota once used it to repair a cracked engine block on his tractor:rolleyes:
  21. Parts48
    Joined: Mar 28, 2008
    Posts: 1,356

    from Tucson, Az
    1. Hot Rod Veterans

  22. ottoman
    Joined: May 4, 2008
    Posts: 292

    from Wisconsin

    I good lock stich repair is as good as new... but not cheap. It depends on were the crack is... is it easy to get at? A 6 inch repair is going to cost $300.
    I wouldnt throw it away but I would first look for a cheaper used block. As the supply of 401's shrink the repair cost will make more sense.
  23. RacerRick
    Joined: May 16, 2005
    Posts: 2,753


    If its an external waterjacket, I would irontite it (lockstitch) and not worry about it. Seen many done. If its internal, the end of the crack can't be found, or ends at the deck or mains, just get another block.

    Also, a lot of shops will price a repair really high if they don't want to do it. I would call around to other shops also. Try Wright Engines in thornhill (905-881-4939) Bill Wright is an old guy who has been doing this forever and practically lives in his shop. His shop alone is worth the trip. Stuff piled to the rafters - neat shit everywher you look.

    He also has at least one nailhead sitting on the shelf (although I think its a 264).

    I have seen him fix stuff that I thought was ready for the scrap bin. He's also semi retired so he sets his own hours - about 5pm until 2 or 3 in the morning.
  24. 49coupe
    Joined: Nov 4, 2005
    Posts: 565


    Thanks for the input and suggestions. I'm going to try and find another 401 block first and explore the repair at another shop.

    I generally like trying to save stuff if possible, but I don't want to spend a lot of $$ fixing something that won't be as good as new.
  25. 49coupe
    Joined: Nov 4, 2005
    Posts: 565


    Just wanted to let you know how it turned out. I took the block to United Welding in Mississauga, ON. These guys repair mostly large truck and industrial engines. This is all they do.

    Not cheap, but they do good work. Mine was an external crack and it ended up being the only problem in the block (thank God).

    They boiled and magnafluxed it, made the repair, put in all new frost plugs and pressure tested it for $380 plus tax. You can hardly tell where the crack was now and they had it back to me in less than a week. They also guarantee their work.

    So I guess it turned out OK.
  26. Jeff Norwell
    Joined: Aug 20, 2003
    Posts: 13,176

    Jeff Norwell
    Staff Member

    Thats GREAT!
    glad it worked out!
    kidcampbell71 and Deuces like this.
  27. Also, Muggy Weld makes some rods to weld cast iron. Drill/terminate the ends of the crack, prep and weld. I've got a 401 which the old guy told me was good, pulled from a '64 Wildcat in his field. Looked it over but wasn't till I power washed and degreased it I found the famous crack by the starter. Looks to be the waterjacket, going to give the Muggy Weld a shot, nothing to loose at this point.

    Anyone else use their rods?
  28. wood remover
    Joined: Dec 23, 2012
    Posts: 987

    wood remover

    Guess it was just a coincident you posted at 4:01 today Lol
    Glad you got your block fixed . 401's are a hard and rare engine to find here in Ontario .
    Getting expensive too ,if you can find one .
    Looking to have one rebuilt , who is doing yours ?? Have a 63 and a 66
    VANDENPLAS likes this.

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