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Discussion in 'The Hokey Ass Message Board' started by johnold1938, Jul 11, 2018.

  1. johnold1938
    Joined: Apr 19, 2009
    Posts: 302

    from indiana

    with summer here I decided to fire up the 32 , in the garage very hot was sweating bullets when I felt my coil it was quite hot mounted on the back of the intake. that's a no gudda. so I came up with a plan to cool it down about 10 degrees or so. did not want to drill any more holes in the fire wall so this is what I made. DSC00049.JPG

    Attached Files:

  2. brady1929
    Joined: Sep 30, 2006
    Posts: 7,595

    from Mesa, Az

  3. 19Fordy
    Joined: May 17, 2003
    Posts: 5,753


    Try wrapping it with some heat insulation.
  4. Nice. I always take them off the engine, just too much heat for them to be happy :)
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  5. big duece
    Joined: Jul 28, 2008
    Posts: 4,827

    big duece
    from kansas

    Great idea. Now that you have lifted the skirt showing some firewall "leg", any other pics of your '32?
    Bandit Billy likes this.
  6. Blues4U
    Joined: Oct 1, 2015
    Posts: 2,558

    from So Cal

    Coils produce heat as they work, if you wrap it with insulation you'll cause it to overheat.
  7. Bandit Billy
    Joined: Sep 16, 2014
    Posts: 3,812

    Bandit Billy

    Then what about coil covers? Seems it would add to the heat issue.
  8. s55mercury66
    Joined: Jul 6, 2009
    Posts: 2,073

    from SW Wyoming

    I would say that is correct.
    Blues4U likes this.
  9. G-son
    Joined: Dec 19, 2012
    Posts: 353

    from Sweden

    These pictures came up on Facebook yesterday, an oil filled coil overheated due to the ignition being forgotten on - when the ignition is on and engine stopped in a position where the points are closed current runs through the coil all the time. Not on a car, but the problem exists on all points/battery ignitions.
    Mounting a coil directly to an engine or insulating it would be less good choices when there are much cooler places to put it in available. Electronic ignitions are way more sensitive, if you have those and want them to survive, keep the electronics as cool as possible - but those usually don't cook the coil if left on, they have built in protection.


  10. Terrible80
    Joined: Oct 1, 2010
    Posts: 462


    Finned aluminum should disapate heat in theory, in real life who knows.

    Sent from my LG-TP450 using The H.A.M.B. mobile app
  11. 19Fordy
    Joined: May 17, 2003
    Posts: 5,753


    Blues4u: Thanks. I forgot about that very important fact.
  12. clarkoh
    Joined: May 12, 2009
    Posts: 16

    from Dallas, NC

    I drag raced for about 30 years. We always put the coli inside the car on the firewall. Might not look that great, but keeps it cooler.

    Sent from my SGP561 using Tapatalk
  13. Mike VV
    Joined: Sep 28, 2010
    Posts: 1,074

    Mike VV

    Correct information.
    Aluminum is a pretty good dissipator of heat. Although there should be actual direct contact between the coil and the alum. cover, no air gap.

  14. G-son
    Joined: Dec 19, 2012
    Posts: 353

    from Sweden

    Indeed, with an air gap the air insulates and it may become hotter than w/o the cover. Even when there is direct contact there is quite a bit of air gap between the surfaces as they are not perfectly flat.

    In electronics a thermal paste is used between components that become hot and the cooling fins that cool them to help heat transfer, it makes a big difference and quite a few expensive thermal pastes has been developed for use in computers (where lower temperatures may allow better performance under some conditions). But in normal situations just about anything works better than air, there has been tests (in computers) where everyday substances were tested against the most expensive thermal pastes and the difference was just a couple of degrees. In the garage I'd simply grab some grease, preferably a kind w/o solid particles (such as MoS2 or graphite).
  15. LM14
    Joined: Dec 18, 2009
    Posts: 1,079

    from Iowa

    Been millions and millions of cars manufactured with coils mounted on the intake. The OEM never had that concern apparently. Ford, GM concerns. Ford put coils on intakes of Y-blocks right up to 460's with no concern. GM stuffed them clear back against the firewall where they got no air at all and they seemed to live for many years there.

    We always put the coils on our circle track cars on the front of the drivers cockpit. Only because we didn't have to move it or mess with it during engine changes. We lost coils with those cars several times and that is a cool place and they were free of most vibration where mounted.

    I mount mine to my engine so the coil wire is short and the installation looks clean. No problems on my last several cars.

    Sometimes we tend to overreact and overengineer something where a problem doesn't really exist.

    I can see isolating things like MSD boxes or other "electronics" but the coil has been mounted on the engine for a long time.

    Food for thought,
  16. 19Fordy
    Joined: May 17, 2003
    Posts: 5,753


    Here's my home made idea. Keeps the coil off the head and fan blade blows air on it. When sitting at idle (hood raised) in the garage for 30 minutes with an ambient temp of 85 degrees, temp. of coil goes to 180 degrees when measured with an digital gun. I am assuming it's cooler when on the road with fresh air blowing in.

    Attached Files:

    Last edited: Jul 15, 2018

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