I suspect your radiator additive is like Redline's water wetter. It's a
good idea to use it, not only because it will probably drop your temp a
few degrees (it's a surfactant, that decreases the surface tension of the
water) but also because it helps lube the water pump seal. At least that's
what they say. It can't hurt, and it won't make a track slippery like
antifreeze will.
For your timing, there are a lot of new and old techniques for deducing
appropriate timing. You can install a knock sensor if you're technically
proficient. You'd need almost any knock sensor and a portable
oscilloscope. Sounds like overkill, but I have a Tektronix portable scope
that I use for a lot of stuff like this. There will be no question about
whether you have preignition or not--the sensor are generally resonant
piezoelectric devices and the put out a heck of a spike when they see a
knock. You might be able to see the output on a good digital voltmeter.
It's also easy to do on a dyno, especially since you can directly see what
the effect of advance is on power. When it stops helping, stop advancing.
Usually that happens well before you see a knock. Especially with low RPM
(less than 10,000) engines.
If you don't have a dyno available, the best is probably a hill test.
Start with about 25 degrees total advance using the grade of gasoline
you're going to use. Get going up a good sized hill and shift early into a
high gear with the throttle wide open. This is pretty much worst case for
preignition, and you'll be able to hear it clearly--it will sound like a
hand full of bearings is loose in your engine. Set your advance forward in
small increments and retest until you hear the noise, then back off a
degree. You probably won't get any useful effect from any spark advance
much more than 32 degrees though a lot of folks run 34 degrees in even
relatively low RPM engines.
-----Original Message-----
From: cj123@ofir.dk [mailto:cj123@ofir.dk]
Sent: Tuesday, May 13, 2003 6:20 AM
To: fot@autox.team.net
Subject: ignition
Hi all
i4m having problems finding the right ignition timing for my spitfire mk3,
it4s runnig with Large valves, flowed head, 89 fast road cam, aprox 9.5
comp.
and a distributor from a 1500, i know it4s very diffrent from engine to
engine, but any guess ? - i cant hear when it starts to pinking and are
affraid to wreck my new engine.
also i have bought some rad-hib extra cool from millers oils, it4s 1:40,
but
can it mix with regular radiator fluid or should it be only water ?
Christian
Denmark
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