Re: Maximum input voltage for "can" style (Lucas/Bosch) ignition coil (fwd)

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Original poster: <sroys@xxxxxxxxxxxxxxxxx>



---------- Forwarded message ----------
Date: Thu, 18 Aug 2005 11:46:53 -0700
From: Ed Phillips <evp@xxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Maximum input voltage for "can" style (Lucas/Bosch)  ignition 
    coil (fwd)

"I wonder what the likely failure mode would be?

Internal short in the HV winding most likely.  The primary (LV) winding
is 
pretty rugged.  However the HV winding is really, really fine wire
(smaller 
than AWG40, I'd guess)."

	I've had two failures.  One was apparently a partially shorted HV
winding and the other was a primary to secondary short due to unknown
causes, but rendered the coil useless as I prefer to run with a real
ground on the bottom of the secondary.  All of these coils (GMHEI) have
been removed from GM distributor caps obtained at the auto parts salvage
store for prices between three and five bucks.  All worked fine when
first used.

	I have another "coil" which was new to me.  Came from some Ford
product.  There are actually three separate coils with separate
primaries.  Both ends of the HV windings have connectors for regular
spark plug wiring, leading me to suspect that this is from a V-6 and one
lead from each side of the HV winding goes to a plug, with the primaries
commutated in some way to serve as the distributor.  Coils appear to be
quite a bit less capacity than the GMHEI.

Ed