Tom,
Some things make you wish for the old days when you timed an engine by
pulling every other spark plug wire and advancing the timing until it
smoothed out. I just had problems that necessitated replacing the entire
fuel injection unit and several gaskets on the 305 C.I.. Vortec engine in my
97 Chev pickup. When they replaced the distributor they gave it 120 of
advance to help it pull better. Three blocks down the street the Check
Engine Soon light was on. The code reader stated the distributor was one
tooth off. It turns out there is a 20 allowance on distributor advance.
The performance chip helps slightly but it's impossible to change much
without the computer getting upset.
Wes
on 4/21/04 4:31 PM, Thomas E. Bryant at saltracer@awwwsome.com wrote:
> John,
>
> I had a similar experience several years ago while attending a Seminar
> by Champion Spark Plug. They had an engine on the dyno equipped with
> spark plugs which indicated cylinder temperature. A little advance from
> the original setting gained a little hp, a couple of more degrees
> advance gained a little more hp and a climb in cylinder temp. A couple
> more degrees gained no hp and the temp went even higher. The next couple
> of degrees dropped power and the temp went through the ceiling. I have
> always remembered that session.
>
> Tom, Redding CA - #216 D/CC
>
> John Burk wrote:
>> Mother Nature enjoys practical jokes doesn't she - I well remember from
>> tuning my AFD you don't always cure detonation by fattening it up - The only
>> thing I remember from 4 years in high school is a seeing movie made by
>> General Motors in the 40s using high speed photography and an engine with a
>> glass cylinder head to learn about preignition - This lead to the wedge
>> combustion chamber Olds and Cad engines in 1949 - Wouldn't we all like a
>> movie inside our engine to see why 42 deg advance works better than 30 deg .
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