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MG MGA - Hot Coil
|After each run the coil in my 1500 gets extremely hot. If one has to touch it he'll get his fingers burnt. My coil is mounted on top of the dynamo as per original specs. I also have a shroud fitted on the rad, but if I remember rightly it used to get just as hot before I had fitted the shroud. Short of moving the coil to another place in the engine bay, can anyone fill me in as to what's best to do to eliminate this problem. BTW it does not affect the running of the engine at all.|
|Mine gets pretty hot, certainly too hot to keep your finger on (Lucas Sport) but I don't worry about it. Just make sure you haven't got a coil that should operate with an external ballast resistor. So my advice if your car is running ok is: 1.) Don't touch your coil when it's hot, and 2.) carry a spare coil in your boot. Lindsay.|
If it's a Lucas coil it will have various numbers on the bottom. The long one is the part number, and the one with letters is the model. This should be HA12 for your car, and most older MG. Sports coils are SA12. If it has something like C7 or C6, maybe with more letters, it's a coil for a ballasted system and is pulling way too much current through the points. As you might guess, the number in these designations is the design operating voltage.
|Fletcher R Millmore|
|Thanks guys. The coil I have has a sticker on the bottom with the part number stamped on it. It reads: DLB101. It was bought from Moss UK, and it was for the 1500. So I dont think it is a ballasted coil. In any case, I think I will follow Lindsay's advice and leave the coil alone and keep a spare in the boot.|
|Frank, that's the correct coil. I think the coil gets extra hot because of where it is mounted. It is close to the engine, which gets very hot, and it is mounted on top of the dynamo which itself runs warm. My ZA Magnette had the coil mounted in the same place, and it too got quite hot but I never had any trouble with it in 25 years of ownership. My MKII midget on the other hand had the coil mounted on the inner wing and had to replace it when it went faulty!|
|I'm not up on those later DLB type numbers, too old I guess!|
Be sure the points gap is correct. Too close = too much dwell = hot coil. (dwell being the percentage of time the points are closed and current is flowing through the coil)
|Fletcher R Millmore|
|Also consider that the oil is slowly leaking out of the coil. I had this brand new coil when I fist got on the road. It would start right up but when I drove for a while and turned it off it took forever to get started again and was really hot. Scratched my head for a month. Finally one day she blew (See Pic) Problem was solved :)
|Many thanks fellas for all your advice. |
I must say that, for originality's sake, I would prefer to leave the coil mounted on the dynamo. I shall now let it be and if it ever fails I'll dig the spare one out of the luggage boot and have it replaced. FRM your info makes a lot of sense too, but in my case the dwell was set by myself and it is spot on 60 degrees. WMR what ever happened to that coil? Did it burst open? Did all the oil inside leak out? Well mate I have never before seen a coil where its top came right off. I am sure that you yourself took the top off. Are you saying that your coil had been leaking oil, resulting in it becoming extremely hot in operation? I had a good look at mine and it's dry all around, no oil.
Anyway, I appreciate all your comments.
|> WMR what ever happened to that coil? Did it burst open? Did all the oil inside leak out? Well mate I have never before seen a coil where its top came right off. I am sure that you yourself took the top off.|
Believe it Frank. I had a similar instance last summer with a new Lucas Sport coil. Coil had been in the car for a couple of weeks. One morning I backed out of the garage, heard a small pop noise, and the engine died. On opening the bonnet, here's exactly what I found.
Last summer I had a Lucas Sports Coil go bad as well and got stranded on the freeway. My coil did not blow apart, but the oil did leak out. It looked like the coil steady plate (Moss, 473-120) front lip was a tad to high for the lip of the coil and when I snugged the coil down on the mounting bracket the coil body was torqued enough to cause the leak.
Moss replaced the coil and I moved the steady plate so it doesn't touch anything, or for that matter serve any purpose now.
|That's amazing Andy, I have never seen anything like that in my many many years of fiddling with motor cars. Well, now I know it can happen with any coil. Lucky for me, I guess, my coil is still in one piece, and there seems to be no oil leaking out of it. Unless of course all the oil has leaked out very slowly every time I drove the car without me ever noticing this happening. I very much doubt it though. Many thanks guys.|
|I apologise for changing the subject of this thread, but what paint did you used on your engine Andy? It looks really smart.|
|r a evans|
|Richard, it's Moss MG maroon engine paint.|
This thread was discussed between 19/03/2010 and 24/03/2010
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