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Technical Dad-blame leaky headers!

Discussion in 'The Hokey Ass Message Board' started by 6sally6, Mar 25, 2019.

  1. 6sally6
    Joined: Feb 16, 2014
    Posts: 902


    Buddys got a 49 F-1 with a 350 shivel-lay engine in it and.....pass side header has a nagging leak! Not sure of the brandof headers but the flange seems thinner than other headers I have messed with.
    We put the thick copper gaskets on it and the driver side seems to have sealed up OK but the pass. side has one port that will NOT stop leaking. We have torqued/cranked on the 3/8 header bolts until we are afraid we will snap it off!!!
    Last resort thang is try some Red RTV on it and try that.
    Anybody got any suggestions?!
  2. squirrel
    Joined: Sep 23, 2004
    Posts: 44,346


    take the header off, inspect it, see where the leak is, see if you can fix what's really wrong with it..
  3. I've posted the part number several times for a Chrysler product many times that will cure it. It's all we use on our Aluminum heads in the race cars (read that No gasket at all). Even on a hot motor and a lean out I've never torched a head at the header flange. It's Bad Ass stuff. 10 times better than the Red junk. I'll dig the number up in the morning and post it up again. I also use it on all other motors with headers and never an issue.
    Atwater Mike, blowby and 6sally6 like this.
  4. Does it have a common flange, often some of those are like a rollercoaster, all over the place. One I had on a Chevy C30 was bad, I cut the flange between the tubes out and dressed up the saw cuts with a grinder, that cured it. Used a good name brand header gasket with that trick.
    Hollywood-East likes this.
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  5. egads
    Joined: Aug 23, 2011
    Posts: 552


    Blue One, XXL__ and hotrodharry2 like this.
  6. Petejoe
    Joined: Nov 27, 2002
    Posts: 10,271

    from Zoar, Ohio

    It’s all about parallel and flat surfaces.
    Remove the header and check for these problems on the offending flange. Remove the gasket and trial fit it with blueing. The poor mating surface will show up.
    File or grind if necessary.
    Last edited: Mar 26, 2019
    da34guy, Hnstray and Andamo like this.
  7. Why would anyone do some stupid shit like that?
    Blue One, scott27, 19Eddy30 and 6 others like this.
  8. chevy57dude
    Joined: Dec 10, 2007
    Posts: 5,183


    As usual, Mr Jim has sound advice.
    The copper gasket style was a little leaky on mine. Mr Gasket paper ones conformed but blow out. Fel Pro with the metal core seems to be holding up well.
  9. Try using a shivola header instead of a Ford header!:confused::D:D:D
    blowby and 31Vicky with a hemi like this.
  10. cshades
    Joined: Sep 2, 2011
    Posts: 451

    from wi

    My 41 coupe was always taking out the header to head gasket and my 40 truck was always eating collector gaskets, so I installed a set of those Remflex gaskets in both and we will see how long the go for. They have to be better than the stupid white gaskets.
    egads likes this.
  11. hotrodharry2
    Joined: Nov 19, 2008
    Posts: 608


    I’ve used these several times as well as filing the header flanges as needed.

    Sent from my iPhone using H.A.M.B.
    egads likes this.
  12. squirrel
    Joined: Sep 23, 2004
    Posts: 44,346


    yeah, I know, Captain Obvious strikes again
  13. blowby
    Joined: Dec 27, 2012
    Posts: 6,188

    from Nicasio Ca

    upload_2019-3-26_7-19-32.jpeg :)

    Don't know how easy it is pull a header of a '49 F1 with a shove rake engine and file it flat but that'd work. Done it several times, usually pulled in at the bolts.

    Last century I worked at a speed shop (Service Center) that sold headers like Costco sells toilet paper. Thorley, Hedman, Hooker, Appliance...everybody was making them, and everybody was buying them. And you could count on it, at least once a week someone would come back wanting a refund. Open the box, greasy, scraped, smashed, dented headers that for one reason or another wouldn't go on. They could be a bear to install, lift engine, pull starter.. If I saw the box coming back from outside I'd try to go on break quickly. :eek:
    Last edited: Mar 26, 2019
  14. Still drinking morning Coffee and reading the Funny paper, er aa the H.A.M.B. board that is. Soon.
    19Eddy30 likes this.
  15. So, Mopar gear sealant is what it's marketed as. I found it about 20 years ago. It has never failed us yet. I learned some time in the 60's with Headers you open the box and fix the Flange no matter the brand before ever trying the Fit in the vehicle. They all need it, some more than others. You never forget those early lessons. This stuff should not be used like calking to fill a Gap but I suppose you could. One piece flange plates seem to be the worst. I like single flange per tube. To each there own.
    This is rated on the package for 625*F but can tell you this. I don't know what it takes to melt pistons on fuel but when it has happened we have not lost a head due to flame out between the head and flange. That's good enough for me. The Mopar part number is 82300234 MS-GF44D Follow the directions and remember clean clean clean the surfaces before applying. Once done right you'll put all those tubes of Red stuff where they belong, in the Trash.
  16. jimmy six
    Joined: Mar 21, 2006
    Posts: 5,191

    jimmy six

    I don't know if this will help but on our dirt car with cross over headers (heavy) we have found the only gasket to work was a Mr Gasket multi layer aluminum crush set. About 30 bucks and we can use them multiple times.
    On my nitro 12 Port GMC we had 3/8" thick flanges and red RTV. No leaks
    My only other advice would be find some cast iron. GM used a lot of styles on that engine and there are some nice after markets too.

    IMO Your tread title should read "dad-gum"o_O
    Last edited: Mar 26, 2019
  17. lostone
    Joined: Oct 13, 2013
    Posts: 942

    from kansas

    One trick I learned along time ago with Pontiac motors, paper style gaskets, soak in 5 gallon bucket of water overnight, install soaking wet, start car and let run until dry. Fixed 99% time.
  18. Atwater Mike
    Joined: May 31, 2002
    Posts: 9,855

    Atwater Mike

    A local older guy here had a '37 Plymouth with a SBC (?) with some leaky headers...engine idling, (roughly, and too fast...about 900 RPM, serious flange leaks...Fast glance I saw 1/4" thick (thin) flanges, IF THAT! More like 3/16", looked like old Hedman that had been 're-flanged'.
    Ah, the miseries of the unwashed...old enough to know better. :rolleyes:
  19. Doublepumper
    Joined: Jun 26, 2016
    Posts: 522


    Besides the header flanges not being flat, I've seen several heads with the exhaust port areas uneven, keeping gaskets from sealing. Just fixed one that was that way recently. I used a large flat file to go across the exhaust ports on the head to get things flat again...worked like a champ. Seems the port areas get eroded over time making them uneven and difficult to seal. Usually it is a problem with the two conjoined center ports on SBC's.

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