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4 Banger OHV Exhaust Port Repair- Any Ideas?

Discussion in 'The Hokey Ass Message Board' started by 38FLATTIE, Jul 7, 2011.

  1. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,350

    38FLATTIE
    Member
    from Colorado

    A friend of mine just spent a chunk of change on an OHV conversion for his banger.

    He got it installed, fired up, and water was running out his exhaust. When he tore it down last night, he found a hole in the exhaust port.

    My first thought was to sleeve it, with a thin sleeve sealed up by epoxy. I can't, however, find an epoxy that will withstand the high temps of the exhaust.

    Mike spent a chunk on this head, and now is looking at a 'cheap', quick fix, to be able to drive the car this summer.

    Any ideas?
     

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  2. revkev6
    Joined: Jun 13, 2006
    Posts: 3,329

    revkev6
    Member
    from ma

    hard to tell from the pic, but if you can get in there with a drill and tap, put a small pipe plug in the hole....
     
  3. Just wondering was the head sold as a good unit?
     
  4. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,350

    38FLATTIE
    Member
    from Colorado

    Yes, but bottom line is, he now owns it, and must fix it.

    Pipe plug idea might work....
     
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  5. terryble
    Joined: Sep 25, 2008
    Posts: 541

    terryble
    Member
    from canada

    If it is that crack we see in the upper right of the last photo take it to a good old timer welder and have it ground out and brazed. It has worked for years when one accidentally "hits water" when porting. A quality brazing artist using top quality rod will fix that in a jiffy probably enjoy it and not charge to much. Considering the investment I'm sure he has in that head don't scimp on the repair... my $.02
     
  6. RichFox
    Joined: Dec 3, 2006
    Posts: 9,570

    RichFox
    ALLIANCE MEMBER

    I have a plug in one exhaust port in the Packard after getting too happy with the die grinder. If you can get to it to drill and tap it works good.
     
  7. jetmek
    Joined: Jan 12, 2006
    Posts: 1,847

    jetmek
    Member

    im guessing thats one of the "denver" miller heads 1980's vintage? i had one with a similar porosity near the spark plug. if the iron is thick enough around the porosity, i would try irontite tapered pin repair from kwikway. many shops use those or stitch lock repair. if you go with weld make damn sure the guy you take it to knows his stuff....
     
  8. It all depends on how thick the material is. From what I can see in the picture it looks like somebody got too happy with the porting tools. It also looks like there is very little material to work with (not that the picture is that great). I'm not aware of any cheap and easy way to fix this - from the looks of it.

    If it is as thin as it looks, my guess is that it will have to be taken to a very professional block repair place - and be welded and/or furnace brazed. There are people that are very good at this - make sure you find an outfit that is very experienced and that they review it before they say they can do it.

    One thing to note, when you do this type of work, you'll probably need to touch up the seats and may even need to deck the head . . . depending on if it warps/moves in the process. All machined surfaces will need to be checked at the very least.

    Not good news - but seeing water coming out of your exhaust doesn't lead to many cheap and easy fixes . . . :rolleyes:
     
  9. jipp
    Joined: Jun 20, 2011
    Posts: 1,116

    jipp
    Member

    i do not ronice the head.. anymore ifno about the engine it bolts up too ? thank.. i thick i would look f'or a good welder.. them good old boys love things like that.. breaks up there normal tractor and plow fixors. errr i mean naps@

    chris.
     
  10. CutawayAl
    Joined: Aug 3, 2009
    Posts: 2,144

    CutawayAl
    Member
    from MI

    Heat the part in a furnace until it's glowing, weld with flux and iron rod, bring back up to temp, then cool slowly. Done by someone with sufficient skill that is the best option, and will produce the best weld. Unfortunately that method will require re-machining of most or all the critical surfaces, valve seats, etc.

    As has already been said, the part can be brazed. Ideally that will be done with a TIG torch and one of several appropriate brazing alloys. The head will be pre-heated, but not to the level previously described. With this method the need for re-machining will be limited only to areas near the weld, and possibly the face of the head.
     
  11. pops29
    Joined: Jun 4, 2007
    Posts: 509

    pops29
    ALLIANCE MEMBER
    from turlock ca

    You should check these guys out. They are located about a mile from my shop and the repairs they do are amazing !!! www.locknstitch.com If anyone can do the repairs these guys can ,, they also sell kits to do it your self
     
  12. tig master
    Joined: Apr 9, 2009
    Posts: 416

    tig master
    Member
    from up north

    Take it to a qualified machine shop and get a professional opinion.Looking at a few pictures here only confirms your findings it has to be seen hands on.It may be non repairable.Many posts in general are from people who want to help but have no idea of the level of expertise that is required to do this repair with success.Welding and stitching are both a form of repair but should be responded to by a shop.It is no good now as it is,and a blotched repair can make it no good forever a talented head shop will give you a creditable opinion.Welding is the least desirable outcome if attempted by backyarder.The old magic nickle rod and a buzz box or my grandfather with the brazing rod did it all the time are mostly failures with a dead player as the result.
    My 2¢ you can make your decisions from here.
    Just trying to guide you along.


    Tig.
     
  13. He is spot on . . .
     
  14. johnneilson
    Joined: Apr 12, 2011
    Posts: 912

    johnneilson
    Member

    Take a few minutes to look at the Lock&Stitch video of how cast iron will crack.
    This pricipal of expansion and contraction applies to all metal.

    As for the epoxy repair possibility, I had cracked a very good SBC head some years ago in my truck. The shop who installed the hardened seats put too much pressure on the seat and cracked the head under the seat. Needless to say, it leaked from time to time. I removed the seat, chased the crack out with a dental file and put in JB weld. cleaned it up, replaced the seat and put it back into service. The epoxy had about 1/8" exposure up into the port not protected by the seat. It ran fine for years, never leaked again. This motor ran about #8 boost from turbo and propane fuel with some short blasts of up to #20 boost, when tires and driveshafts were available.

    J
     
  15. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,350

    38FLATTIE
    Member
    from Colorado

    Thanks Guys! I've sent this info to Mike, so that he has options. I'll let you know how he proceeds.
     
  16. T__N__A
    Joined: May 31, 2006
    Posts: 336

    T__N__A
    Member

    Thanks Buddy! Thanks everyone else for all the info. I'm going to take a look into drilling a tapping the hole as revkev6 and richfox has mentioned. If not I will be look for a good cast iron welder! Anyone know of any cast iron welders in Northwest washington?

    -Mike
     
  17. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,350

    38FLATTIE
    Member
    from Colorado

    Contact Pete1- he's only about 150 miles from you, in Elbe, and probably knows someone.
     
  18. My suggestion is to take it to Pete BEFORE you start screwing with it! If you start drilling/tapping, you may remove the very material that Pete or somebody like him needs to weld on. Take it to somebody FIRST - to reduce the chance of ruining the head. There has to be quite a lot of material in order to lock/stitch it -- if it is so thin that the casting broke through, then you probably have no material to work with . . . as you're in the water jacket. I can't tell this by looking at the picture, but it is sure what I suspect.

    Best of luck!
     
  19. Dynaflash_8
    Joined: Sep 24, 2008
    Posts: 3,010

    Dynaflash_8
    Member
    from Auburn WA

    Either braze or JB weld.
     
  20. Take it to an experienced professional, to be repaired correctly.

    Amateur cheapie repairs could destroy the head.
    There is a point of no return.
     
  21. tig master
    Joined: Apr 9, 2009
    Posts: 416

    tig master
    Member
    from up north

  22. 38FLATTIE
    Joined: Oct 26, 2008
    Posts: 4,350

    38FLATTIE
    Member
    from Colorado

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