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shrunken Exhaust Manifold ??

Discussion in 'The Hokey Ass Message Board' started by Boones, Mar 8, 2012.

  1. Boones
    Joined: Mar 4, 2001
    Posts: 9,691

    Boones
    Member
    from Kent, Wa
    1. Northwest HAMBers

    I bought a sbc cast iron exhaust manifold (off a mid 80's truck) to install on my 327 I am putting in my 51 chevy. I decided to drop in my mock up motor/trans to ensure my new motor and tranny mount were in the right locations. since the exhaust manifolds on the driver side are usually the problem with fitting a V8 into a stock susp chevy I thought I would bolt on the exhaust manifold and drop it in.

    Problem. Bolt holes will not line up. thought maybe my plastic mock up motor had the bolt holes miss located. Decided to bolt to the actual motor and they will not fit either.

    The holes from the outer bolt holes appear to be a 1/4" off (to short). Has anyone ever run into an exhaust manifold shrinking and is there a way to stretch it back into shape (I do not have a torch). I did try using a com- a-long to spread but I am not getting much movement.

    What are my options.. find another manifold? borrow a torch from someone and heat the shit out of it with the come a-long.
     
  2. N.A.P.A. (I'm sure any tool truck will have it also.) sells a tool to spread the manifold. It is very common. The tool is inexpensive and works well.
     
  3. They make a manifold stretching device. I've seen them in summit racings tool catalog. It is placed between the center and out board ports then tightened, allowing you to line up the bolt holes.
    Matt
     
  4. VonWegener
    Joined: Nov 19, 2009
    Posts: 786

    VonWegener
    Member

    Don't get the Harbor freight version it will only last for doing 2-3 manifolds. You will encounter shrunken manifolds often when working on cars so invest in a quality tool early.
     

  5. 55chieftain
    Joined: May 29, 2007
    Posts: 2,188

    55chieftain
    Member

    The tool I got from napa was made by Lisle to do mine, it was under $15 I believe
     
  6. 50ChevyFrank
    Joined: Sep 5, 2007
    Posts: 229

    50ChevyFrank
    Member

  7. Yeah Ken, buy the lisle tool or make your own after looking at theirs. I did not need the tool last time but forget how the heck I got them spread?!
     
  8. Cadillacjerk
    Joined: Nov 16, 2010
    Posts: 93

    Cadillacjerk
    Member

    I use ready rod ....thread into the cylinder head at each end, leave about 8 -10 inches of rod out from the block, place the manifold on the ready rod , run it in with nuts evenly and slowly...if ya want warm the manifold up with a torch a bit ...suck it in with the nuts, when it mates the head run the factory bolts in to the adjacent holes...easy
     
  9. snaptwo
    Joined: Apr 25, 2011
    Posts: 696

    snaptwo
    Member

    A 1/2" bolt and high nut will do the trick. They finally went to a reinforcment rib to stop that shrinkage.
     
  10. falconwagon62
    Joined: Mar 17, 2006
    Posts: 1,431

    falconwagon62
    Member

    don't swim in cold water either!!! I hate Shrinkage.....
     
  11. william.ali.kay
    Joined: Nov 20, 2009
    Posts: 824

    william.ali.kay
    Member
    from Milwaukee

    Yup, heat it up with an oxy acetylene torch and a rosebud tip if you have one on hand.
    Keeps me from worrying about cracking.
     
  12. Edd
    Joined: Nov 8, 2003
    Posts: 222

    Edd
    Member

    Back in the late 80's our local Chevy dealer just told us to enlarge (drill) the two outside holes...it worked! ie police cars...
     
  13. Don's Hot Rods
    Joined: Oct 7, 2005
    Posts: 8,319

    Don's Hot Rods
    Member
    from florida


    That spreader tool will work for that too, but you aren't going to like it very much. :eek:

    Don
     
  14. tractorguy
    Joined: Jan 5, 2008
    Posts: 894

    tractorguy
    Member

    Another trick is to simply put in as many bolts as you can finger tight and then run the engine to warm the manifold up evenly and the bolt hole will most likely line up. Put the last bolt in, tighten all bolts.
     
  15. Boones
    Joined: Mar 4, 2001
    Posts: 9,691

    Boones
    Member
    from Kent, Wa
    1. Northwest HAMBers

    Went to Napa and bought a Manifold Spreader tool. worked just fine
     
  16. Atwater Mike
    Joined: May 31, 2002
    Posts: 11,625

    Atwater Mike
    Member

    I had a neighbor with an El Camino that had that problem. I helped him with it, loaned him my Chev manifold stretcher. When we got the bolts started, he got real bold...
    Told me how his El Camino could give my 63.5 Galaxie a race.

    I asked him if he had a tool he hadn't told me about. A 'TRUTH STRETCHER'.

    He tightened the bolts and thanked me. LOL (Merced, 1995)
     
  17. Atwater Mike
    Joined: May 31, 2002
    Posts: 11,625

    Atwater Mike
    Member

    By the way...How hot do you get the manifold when matching the ports?

    Can you ever get there again?....

    Chevy love. Chevy Volt.
     
  18. I have never encountered this. I guess you can teach an old dog new tricks.
     
  19. JD Miller
    Joined: Nov 12, 2011
    Posts: 2,221

    JD Miller
    Member

    Yea they "shrink". I ground the shit out of the holes and ports for temperarly running them,then pulled them off. Throw them out in the back yard in the dirt. Thats were mine are. Doug Thorley headers replaced them, Great header, super thick flange, never leak or need new gaskets
     
  20. Willy301
    Joined: Nov 16, 2007
    Posts: 1,426

    Willy301
    Member

    I just got my Summit tool catalog in the mail today, and as I was reading along in the porcelain library, they have the spreader tool, and it is only 7.50 from them...plus I saw something else from them on their website about free shipping...but you probably have to have a minimum order or some other thing for that....
     
  21. Here is what it looks like.
     

    Attached Files:

  22. tfeverfred
    Joined: Nov 11, 2006
    Posts: 15,791

    tfeverfred
    Member Emeritus

    Hell, I've never even HEARD of it.:confused:
     
  23. Boones
    Joined: Mar 4, 2001
    Posts: 9,691

    Boones
    Member
    from Kent, Wa
    1. Northwest HAMBers

    that is why my tool looks like ( sounds like summit is cheaper than NAPA but I did not have to wait, I got it and fixed the issue). Headers are an option but only Sanderson makes a set to work with the factory steering and v8 conversion. if this manifold does not work, that will be my solution but its alot more money...
     
  24. It is only certain manifolds that do this.

    Randy, looking forward to seeing your crew on teh salt this year, you should pit next to us, make my trip for Tecate shorter AND I could man the grill and provide some killer brats at times. ;)
     
  25. Looking forward to Bonneville too. My main criteria for my pit site is near the porta potty. We need to coordinate sites............
     
  26. Pooch
    Joined: Apr 11, 2006
    Posts: 867

    Pooch
    Member
    from Oklahoma

    This manifold without the top bar.
     

    Attached Files:

  27. newrider3
    Joined: Aug 19, 2010
    Posts: 62

    newrider3
    Member

    For a minute I thought you guys were jerkin us around. Like sending the new guy to grab a board stretcher after he cuts some lumber too short.
     

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