Plug reading indeed is an art. I spent a lot of hours at the Champion
school in Toledo and then countless hours from the dyno and the track
learning the art. There is as stated by Bill " No way to gather info from a
used or already dirty plug." My practice was to have at least a half dozen
clean plugs with me at every test session. On a four cyl engine I'd put a
clean plug in the number two hole ( generally the leanest due to the flow of
the fuel in the crossover pipe) and on a six in the number two and number
five holes., you don't need a whole set to get the reading, but they due
need to be clean or new. Run a couple laps ,cut it clean and look at the
plugs you have just put in. Replace them with other clean plugs and do it
again after you've made the changes you think it needs. Works wonders in
the performance and the relability. One of the things that shows up lots of
times and is very confusing to most folks is the rubber or debris from
off-track excursions. Even with filters this junk winds up on the plugs and
can look like detonation traces. The melted tiny balls of rubber look just
like aluminum and you need to look very close to see that they are black and
shiney not aluminum which is silver and shiney. Dick Gale is the guy who
was at the track for so many races. Great guy and a great friend. Bobby
Strahlman was another fellow for Champion. I did a ton of work for Champion
of dynoing engines with their engineering plugs before they were put on the
market.
----- Original Message -----
From: Bill Babcock <BillB@bnj.com>
To: <TRBILBO@aol.com>
Cc: <fot@autox.team.net>
Sent: Thursday, July 13, 2000 4:42 PM
Subject: RE: TR4A plugs
> Oh, one other thing. I learned plug reading from a plug wizard that
champion
> used to send to the races--can't recall his name but he was a great guy
and
> really new plugs inside and out (literally). Some things he showed me are:
> -- plugs should always be read at the base ring--the little circle of
> insulation that you can see at the bottom of the insulator--as well as the
> sides and tip. You need a good light and magnifier to properly read plugs.
> -- There's no such thing as reading a plug without a clean chop--if you're
> trying to figure out what's happenbing at full throttle then your chop has
> to happen at full throttle after a pretty long load--up hill is best. Cut
> the ignition with the throttle wide open and coast to a stop. Likewise any
> other throttle position.
> -- The second place you look is at the edge of the center electrode. If
the
> plug is too extended, the base insulator might look fine but the tip edge
> will be rounded from melting. You also want to look at the center of the
tip
> electrode (assuming it's not a platinum tip where the wire is too thin to
> see anything) for a clean little ring of splatter from the sparks. If it's
> not there your coil polarity might be reversed (look inside the side
> electrode) which can give you fits with a high compression engine--you may
> get misses at full engine load since it takes more potential for the spark
> to jump from the relatively dull side wire. Sharp edges enable sparks to
> jump at lower voltage (read up on corona effect if you think that sounds
> silly)
>
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