I have a coil that is mounted totally upside down & haven't had any problems
with it. Even the shop manual shows it that way. Not saying it's right
(maybe GM just wanted to sell more coils), just an observation.
Regards,
Doug Pewterbaugh
dpewter@msn.com
Denton, TX
49 3104 216 5-window
-----Original Message-----
From: Tom Burt <tburt@hirose.com>
To: 'Kevin Lake' <lakek@oit.edu>; 'Wayne Osborne' <wcosborne@inetnow.net>
Cc: 'oletrucks' <oletrucks@autox.team.net>
Date: Monday, April 05, 1999 1:59 PM
Subject: [oletrucks] Misfire Misdiagnosis
>Wayne/Kevin/oletruckers,
>
>How my truck was blessed on Easter Sunday: A success story to be shared
with
>the oletrucks list.
>
>Easter Sunday I had to deliver four sheets of plastic lattice to my
>brother-in-laws 25-miles away. Being my wifes brother, she insisted that I
>take the '57 truck. I resisted at first, but then yielded to her request.
>En route I nearly chipped a tooth from gritting my teeth while the truck
>repeatedly misfired. We finally made it there without breaking down.
>While visiting, the niece's boyfriend volunteered to take look under the
>hood. His observations were as follows:
>
>1.) I had mounted the ignition coil (going clockwise) 135 degrees from
>vertical. This was for two reasons: so that the coil wire would reach the
>distributor and so the bracket be mounted on a flat surface on the firewall
>(recall curved depression feature on cab firewall). I was told by
>autoparts folks that the coil is sealed and that orientation was not a
>problem.
>His Response: Coils must be mounted vertically so that the oil inside
>provides a sufficient dielectric. Any mounting otherwise will weaken or
>damage the coil windings.
>
>2.) The only ground he observed was a strap running from the
>tranny/bell-housing to the cab.
>His Response: To ensure a good ground, straps should be attached from the
>engine block to the frame. The webbing on the cab to frame coupled with
>aluminum from bell-housing were two points that could conceivably cause
>poor grounding. Poor grounding may cause points to burn faster and HEIs to
>breakdown.
>
>Turns out, this guy works for Mallory and knows the product pretty well.
> So while there, I gave it a try and reoriented the coil to a vertical
>position. I took it for a test spin and...the misfire disappeared. As for
>the grounding, I plan to add a new strap as suggested from the block to
>frame. He also asserted that for ignition systems GOOD WIRING IS A MUST!
> Something I have to reflect upon since my truck was wired by the PO!
>
>Tom B. 57 Stepside 3200
>
>
>oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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