Register now to get rid of these ads!

Technical You ever have a coil to EXPLODE?

Discussion in 'The Hokey Ass Message Board' started by the-rodster, Jul 15, 2020.

  1. the-rodster
    Joined: Jul 2, 2003
    Posts: 6,623


    Yeah, me neither.
    I mean, who is dumb enough to leave the ignition on?

  2. KoolKat-57
    Joined: Feb 22, 2010
    Posts: 2,947

    from Dublin, OH

  3. 31hotrodguy
    Joined: Oct 29, 2013
    Posts: 1,474


    Driver50x likes this.
  4. In the 70’s, I had rented a small wood frame house with a one car wooden garage,white sheetrocked painted walls. I had a t bucket roadster,full race flathead with 12 volt ignition.I turned on the inside garage lite one morning and saw thousands of small black spots adorning the walls and ceiling; they were everywhere and were stuck like dots of black glue. Further inspection revealed the top of the coil had exploded and there was a large coil spring sticking out of the top of the coil.No, I did NOT leave the switch on, but a “short” must have occurred causing the coil to “blow its top” and I guess the coil oil got heated when it exploded and all those little black dots were liquid when it blew and dried into thousands of little black dots that stuck to the walls and the roof of the gloss white garage. I ended up having to repaint the white over the black dots, but it was like painting over thousands of bb’s like those used in a kids BB gun. It was terrible, something I had forgotten until reading about exploding coils.The landlord was understanding, but the walls and ceiling were “bumpy” with dried coil oil everywhere; there were thousands of little black dots.
    Register now to get rid of these ads!

  5. Jalopy Joker
    Joined: Sep 3, 2006
    Posts: 24,898

    Jalopy Joker

    old coils, way coil mounted, wiring problem, key on, etc - coil usually is something that most never think twice about - have had a battery explode upon just starting a stock car with no warning problems - diodes in alternators can fail with ignition off and cause fire
    VANDENPLAS likes this.
  6. putz
    Joined: Jan 22, 2007
    Posts: 531

    from wisc.

    i left the key on had a petronic set up and a new hot coil it actually melted the coil right out of casing ....
    Driver50x likes this.
  7. Marty Strode
    Joined: Apr 28, 2011
    Posts: 4,807

    Marty Strode

    I had a MEL in a dune buggy, and in my haste, didn't install a ballast resistor ahead of the coil. I managed to flip on the ignition toggle switch, without starting the engine. After it sat for a short while, I heard a "pop", it blew the bottom of the coil off, and sent it sailing, while still hanging on the fine copper wires. There was melted plastic sprayed all over. The buggy had 2 large 6 volts connected in series, plenty of battery power.
    Driver50x and Hnstray like this.
  8. 62SY4
    Joined: Oct 30, 2009
    Posts: 52

    from Boston, Pa

    With the points closed your coils's primary winding acts nearly as a dead short.

    Check your points they may have welded shut.
  9. noboD
    Joined: Jan 29, 2004
    Posts: 7,157


    Or all the tension out of the overheated spring on the points.
  10. the-rodster
    Joined: Jul 2, 2003
    Posts: 6,623


  11. the-rodster
    Joined: Jul 2, 2003
    Posts: 6,623


    I had a spare coil under the seat and was on the road in ten minutes.
    Driver50x likes this.
  12. I had a 6 volt coil blow up on me when I was jump starting the car.
  13. hotrodjack33
    Joined: Aug 19, 2019
    Posts: 976


    I had my Wife blow-up when a $1800 order arrived from Speedway:eek:
  14. jaracer
    Joined: Oct 4, 2008
    Posts: 321


    While I was student teaching, my instructor had been asked to make a sparking device for a demonstration on flammability of various liquids. We discussed this with other instructors and got the idea that connecting an ignition coil to 110 would give a constant spark. Inductive reactance should limit the current flow since the direction of current flow is changing at 60 hertz. It sounded feasible and testing revealed a constant spark. However, current flow wasn't as limited as we theorized and oil started to spew out the end of the coil. It didn't blow, but the case bulged and it smelled terrible.
    Hnstray likes this.
  15. Mr48chev
    Joined: Dec 28, 2007
    Posts: 26,857


    I haven't had one blow but have repaired a car that one blew on. Under the hood looked pretty much like what flatheadJohn47 Described on the shop walls. Someone had left the key on on that one though.
  16. Baumi
    Joined: Jan 28, 2003
    Posts: 2,409


    Mine didn´t completely blow apart, but it spilled the oil all over and wouldn´t produce a spark over 3000 rpm... Took a few hours until I found what´s wrong
  17. 67L36Driver
    Joined: Jun 1, 2020
    Posts: 67


    A mechanic where I worked had a coil blow up on a fork truck as he was bent over the engine. His safety glasses prevented him from being blind.

    He recovered at home for a week with the burns to his face.

    Do not lean over coils or engine fans. (Blade took the bill off a fellows baseball cap in the pits one Friday night.)
    Driver50x likes this.
  18. MikeG5211
    Joined: Jul 7, 2019
    Posts: 61


    Just reading this thread made me paranoid enough to go check to make sure I unscrewed my battery disconnect.
  19. jetnow1
    Joined: Jan 30, 2008
    Posts: 1,528

    from CT
    1. A-D Truckers

    My best friend used to work for Echlin/Accel , I was at a party at his house and one of his co-workers
    was there, he had just returned from testifying at a law suit. Seems someone had bought a coil, installed
    it and it exploded. The defense pointed out the application for the coil was a 6 volt tractor, he installed it
    on a 12 volt vehicle with the opposite polarity.
  20. X-cpe
    Joined: Mar 9, 2018
    Posts: 947


    I've done it twice. Once hot wiring a donated car and forgot to take the jumper wire off after it died. The second time on a MegaTech glass demonstration engine. Ran it out of fuel, the bell rang, didn't turn it off, went to lunch. That oil stinks.
  21. King ford
    Joined: Mar 18, 2013
    Posts: 1,342

    King ford
    from 08302

    It appears that the coil in question as mounted vertically, it is my understanding that the “ old” oil filled coils are supposed to be mounted horizontally so the oil can cool all of the windings....any of the ones you guys have seen explode been mounted horizontally?
  22. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 5,033


    60 hertz at the coil is equivalent to an otto cycle V8 running at 900 RPM.

    4 sparks required per crankshaft rotation
    900 RPM requires 3600 sparks per minute
    3600 sparks per minute divided by 60 (seconds per minute) equals 60 sparks per second (equivalent to 60 HZ).

    Is it any wonder that points bounce and spark can become erratic at high RPM's?
  23. blowby
    Joined: Dec 27, 2012
    Posts: 6,582

    from Nicasio Ca

    Surprised it didn't blow that first. With the Igniter 2, btw, it's supposed to turn itself off if the key is left on.
  24. flynbrian48
    Joined: Mar 10, 2008
    Posts: 6,410


    Yup, me too. Left the ignition on inadvertently in our Chris Craft with a 283 and blew the coil to smithereens. Black all over the engine and inside the engine box.
  25. blowby
    Joined: Dec 27, 2012
    Posts: 6,582

    from Nicasio Ca

    Buddy of mine was telling me just last night that his battery was dead from leaving the ignition on, fortunately no coil explosion.

    But it got me wondering: Modern electronic ignitions have build it safety that turns them off if the key it left on. Might it be possible to design a gizmo for point systems that could also sense a load on the battery without any change (engine running or generator charging) over some time period and stop current flow?

Share This Page

Register now to get rid of these ads!


Copyright © 1995-2020 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.