Bruce---It's simply too easy to say that your engine performance would
improve by going to the lighter advance springs.
Then again, it's easy and cheap enough to try them to see, IF you can
quantify the results. A lot would depend on at what rpm your engine
starts complaining (pinging). All engines will of course, if the timing
is advanced too far and put under a load. If your engine starts
hammering below the 3,000 mark, then going to springs that brings the
timing in earlier could make it worse.
A distributer machine will plot the advance curve for you, but won't
necessarily tell you if these lighter springs are the way to go. (You
may find heavier springs with more initial advance to be better)! There
are road tests to compare such things. Also check out p.139+ in
Kastner's new book.
Dick
From: brucesimms2003@yahoo.ca (Bruce Simms) Date: Tue, Dec 16, 2003,
2:26pm (PST+3) To: 6pack@autox.team.net Subject: R Williams Book &
Re-curving Advance
Williams & other Brits such as Moss Europe suggest that later cars could
benefit by having their distributor advances re-curved to more closely
match the early PI profile. He suggests that total advance should be
in by 2800-3000 for a fast road car, as opposed to 3200-3400.
Moss Europe has a pack of alternative distributor weight springs
available to re-set the advance. The weaker springs bring the advance in
earlier. I guess I need to find a shop with a distributor setting
machine to get this work done. Trial and error could be painful.
I have 9.5 compression, flowed head, early PI profile camshaft, HS6s
with BCC needles, sport coil and Crane 700 conversion.
Is the advance re-curve applicable and worthwhile? Pluses/minuses?
Thank You,
Bruce Simms
CF1941UO
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