Here's what I always thought: Small gap = cooler spark
I have a book on building high performance small blocks.
One of the suggestions is to file off the upper electrode such that it is
in alignment with the edge of the center electrode. They claim you can get
an additional 5 HP boost, but not without a shorter plug life.
Tom B. '57 Stepside 3200
-----Original Message-----
From: Bill Bailey [SMTP:billb@gamewood.net]
Sent: Monday, July 19, 1999 4:16 AM
To: oletrucks@autox.team.net
Subject: [oletrucks] HEI Spark Gap Question
I went to change the plugs in my truck this weekend and noticed something
that surprised me. The engine is a small block (350) that has a factory
HEI distributor on it. I do not know what it came from as it was in the
truck when I bought it.
When I took the first plug out I noticed that it was gapped at 0.035" which
seems small to me. With HEI I would have expected around 0.060". I am
wondering if the engine originally had breaker points and some PO changed
to HEI and didn't re-gap the plugs. What would be the result of a gap
that is too small? The electrodes have some wear and dry muck on them that
I would associate with mileage. The engine runs good except every now and
then it sounds like a cylinder might not fire completely, a hiccup kind of
thing. That is what prompted me to change the plugs. I've always had
trouble with the exhaust smelling too rich no matter how much I adjusted
the mix. Could a small gap cause this?(thinking the spark might not be
burning off all the fuel)
I'd appreciate any enlightenment that anyone could give me
Bill Bailey
57 Chevy 3100
http://members.tripod.com/~oltruck
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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