Heat exchangers not fitting Type 4

Discussion in 'Mech Tech' started by orwell84, May 4, 2021.

  1. E00A169B-9A95-498E-A6EF-60887FFA0A22.jpeg DF3AEC57-E9E9-47CB-9CB4-766A233120FE.jpeg 1840BD92-F356-4672-9E9C-2EA95AE6E3C0.jpeg
    I am in the process of building a type 4 2 liter.

    I am trying to fit heat original oval port heat exchangers. One side fits, the other side doesn’t, even with the studs removed.

    It looks like the flanges are fouling on the castings. They are amc 2 liter heads. The pipes are not bent, they fit on an old set of 1700 heads, same thing with another heat exchanger I have.

    The only solution I see is grinding away some of the casting but not sure if this will damage the head of if there is something else I’m missing. Thanks for the help.

    1700 head first photo
    Following photos 2l AMC head
  2. I did a bit of manifold and head filing and mine were vw 1800 heads but exchanger may ave been 'adjusted' to fit the 2ltr head it came with, Reamed the mounting holes a smidge too


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  3. Mine needed a bit of "adjustment " with a file and drill to make them fit ... the exchangers were from JK 10 years ago, so things don't appear to have improved.
  4. All oval port type-4 heads (should) have the same exhaust fitting dimensions.
    77 Westy likes this.
  5. I tried tellling mine it should fit.. in quite strong language, some of it threatening, but it wouldn't listen..

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  6. Mine are originals. It takes some wiggling to get it in the 1700 head but the AMC heads are a no go as the casting is definitely different though the j pipes I ran before fit fine.
    67DC44DE-FE4A-450A-85C3-FB9F2EA70BD0.jpeg 215215E5-1C30-491B-9858-507A873DF983.jpeg

    There has already been some clearancing done at the factory. The heads were built by Hoffman automotive. He would probably do it for me but I imagine it’s not that hard. Put something over the exhaust ports and grind slowly until it fits.
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  7. Time to get the Dremel out, I think...
  8. The Dremel is my go to tool for this kind of thing. A die grinder with a carbide burr takes off material way too fast unless you do this kind of thing for a living.

    Better to go slow and sneak up on it.
    Iain McAvoy, paradox, CollyP and 2 others like this.
  9. I really should do a restoration thread. It’s been inching forward like a glacier for years now. I will try to give the Hemingway version.
  10. Do it! We’d be interested to see it.

    Be better if you did it Raymond Chandler style. Then you could use the word “sweetcheeks” :thumbsup:
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  11. B84FF1AD-1A23-44E7-8041-DD5B7DE1EF79.jpeg Just an update;

    I tried fitting my junkiest heat exchanger for the 1/2 side and surprisingly it fit perfectly. The flanges seem to be a little smaller as well as the tubing. I wasn’t aware that there were variations among the same basic style of heat exchanger.

    Unfortunately the one that fits is in rough shape. Pipes are rotted away at the muffler end and the exhaust flanges leak where they meet the pipe. My best option still might be to clearance the head casting.
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  12. Nor me. Could you measure the different tube diameters?
  13. I will measure them when I get home.
    zedders likes this.
  14. So the the heat exchanger flanges I am trying to fit are about 1.25 mm x .25mm larger and are slightly rounder. I managed to clearance the heads and they seem to be bottoming out but leaked through the flanges a little when torqued with the gaskets. The flanges are flat, straight and parallel. Not sure how to get them to fit better or if something is still preventing them from seating. CAC998E6-8147-415F-A082-B2BB70F3705C.jpeg 6CD90C1A-5A5C-4724-8C95-07EDB4D46156.jpeg 8FB4F28C-689B-438B-AD83-D3C44F6AF7FE.jpeg D343D42A-947A-4A4E-BC37-DEAD2A835BC0.jpeg
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  15. Last tme I fitted genuine exchangers to genuine heads I persuaded them with a mallet. 5hey we’re just a little tight. Studs guide em in but this looks a bit more than that. Btw anneal those copper rings prior to fitting
  16. Thank you. I think I will smear some grease on the gaskets and torque it down to see if it squishes it evenly. If it’s hanging up somewhere, I will have to do more grinding.

    Seems that aftermarket everything, even good quality requires some arts and crafts to get it to fit.
    snotty and Dicky like this.

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