Register now to get rid of these ads!

Cracked block

Discussion in 'The Hokey Ass Message Board' started by RDP, Feb 5, 2012.

  1. I don't know why guys say jb weld wont work. we ran a junk 400 block all season(circle burner) with a crack in the lifter galley where it had frozen(we didn't know it when we peiced it together until we filledit and could hear water running into the oil pan) tepaired by jb weld. track champions by a long shot.
     

  2. Ni rod and a Lincoln welder is your best bet. it is not something that is hard to do and unless you have a line on 25 or 30 dollar blocks it is going to be your cheapest solution.
     
  3. Ha Ha Ha! LMFAO!!!

    Ya' got me!

    Ya' got the Tater!
     
  4. Mr48chev
    Joined: Dec 28, 2007
    Posts: 33,861

    Mr48chev
    ALLIANCE MEMBER

    Ditto, Small block Chevy blocks of any size are too easy to come up with to want to spend the time and effort to try to save. As Jim said, the only ones a guy might want to put the effort in are ones that have some rare code or may be the key to keeping a 100% restoration 100% matching numbers.

    The only other reason to try and save it is that if it has already had lots of dollars spent on machine work.

    Usually that crack is due to neglect as in the last guy who had it didn't think enough of it to put antifreeze in it.
     
  5. 57Custom300
    Joined: Aug 21, 2009
    Posts: 1,424

    57Custom300
    Member
    from Arizona

    I was having my 272 yblock bored to 292 when the machinist noticed a crack in the same place as yours. He sent me & my block to a welder that said he could weld it and it should be OK. Not running yet so I'm keeping my fingers crossed.
     
  6. RDP
    Joined: Dec 3, 2010
    Posts: 242

    RDP
    Member
    from Kansas

    Thanks for all the input! I can always count on HAMBERS for some much needed info.
     
  7. Ghost of ElMirage
    Joined: Mar 18, 2007
    Posts: 758

    Ghost of ElMirage
    Member

    whats the casing number? If its rare fix it. If not then use it for a boat anchor
     
  8. Mr48chev
    Joined: Dec 28, 2007
    Posts: 33,861

    Mr48chev
    ALLIANCE MEMBER

    I went back and read though the thread again. If it's cracked on the outside are you sure it isn't cracked on the inside of the waterjacket?

    20 something years ago I had a student pull a Mopar of some kind with a 440 in it in the shop because it didn't have antifreeze or enough of it and the block froze. He drug it in on Friday afternoon and we left for the weekend. On Monday there was a lake of oil and water under and around the car because the block had cracked on the inside and the ice/water melted and filled the oil pan until it pushed the oil out the breather.

    If you weld it yourself all you will be out is time and the cost of the welding rod. If it doesn't work 400 blocks aren't that hard to find.
     
  9. RDP
    Joined: Dec 3, 2010
    Posts: 242

    RDP
    Member
    from Kansas

    The oil pan was clean and had no water in it so I am going to assume that it didn't do any damage internally.
     
  10. Rookie1
    Joined: Apr 5, 2009
    Posts: 63

    Rookie1
    Member

    How much is it worth to you ? you can buy another block for what you'll pay to weld it. Will someone that welds cast iron guarantee it, i doubt it. 50/50 crapshoot at best. you would be better off gambling on an over the counter block sealer. I've sealed only one and i used waterglass (sodium silicate) .
     
  11. 39 Ford
    Joined: Jan 22, 2006
    Posts: 1,558

    39 Ford
    Member

    JB weld is indeed just a glue, but it does work. The cost of trying it is minimal and the block does not have to come apart. You can improve on my original post by screwing a small steel plate over the hole while doing the JB weld process. After it is done and dried fill the system and pressure check the system. If it holds pressure for several hours then chances are its fixed. The radical ideas here are said by folks with deeper pockets that me. Cheep is good.
     
  12. BuiltFerComfort
    Joined: Jan 24, 2007
    Posts: 1,619

    BuiltFerComfort
    Member

    I've seen JB weld held down by a bar between the two freeze plugs - they just drilled into steel freeze plugs and put stainless bolts through them from the engine side, and used the threads to hold a patch tight to the crack. It still weeped a little but there was NO prep other than spray the crack with carb cleaner and hope for the best. So, give it a try, not much to lose; if it fails then you can find another block or get it stitch welded.
     
  13. Why couldn't it be brazed? As for JB weld, I think if there isn't much pressure on it, it would work because I once bought an inboard/outboard boat that I ran for a couple of years before I discovered about a 4 inch long crack had been JB welded on it. Had it a couple of more years before I sold it. It never had a problem, but marine engines are not cooled with pressurized water so that may have made a difference.
     
  14. super plus
    Joined: Dec 14, 2006
    Posts: 566

    super plus
    BANNED

    This is what I did , First I drilled a hole at each end Then I taped each hole 5/16 fine threads . I Vd the crack a little & used JB weld . Then I made a 1/4 in thick aluminum plate & gasket with silicone about 1 1/4 in wide & bolted it to block , No leak
     
  15. gasserjohn
    Joined: Nov 9, 2008
    Posts: 1,218

    gasserjohn
    Member

    if you have any skills at all you can fix for cost of the cast iron plugs drills and a tap cheap only takes time...........
     
  16. super plus
    Joined: Dec 14, 2006
    Posts: 566

    super plus
    BANNED

    PS The crack was about 3 in long
     
  17. Shopking
    Joined: Jan 10, 2009
    Posts: 106

    Shopking
    Member
    from central Pa

    Had a 56-265 corvette engine stiched in the same spot last year.It has held up water tight.Cost was about $300.Pretty pricey but it was a numbers matching original engine.
     
  18. Rookie1
    Joined: Apr 5, 2009
    Posts: 63

    Rookie1
    Member

  19. since it seems to be a external crack just drill a series of holes starting in the ends along the crack and braze it up. having someone with propane torch heating area during the brazing proccess helps the flow of the braze. i fixed a 235 head 30 years ago and the engine is still in vehicle running strong.
     
  20. flatheadgary
    Joined: Jul 17, 2007
    Posts: 1,012

    flatheadgary
    Member
    from boron,ca

  21. paleot
    Joined: Aug 29, 2011
    Posts: 232

    paleot
    Member
    from louisiana

    Check with your local machine shop, they can do a stitch lock repair. The stitch lock repair replaced the old irontite repairs. I have a flat head with repairs through two valve seats! seated the valves right on top of them did not replace seats.Go to stitchlock .com they are used all through industry.
    Tony
     

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 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.