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Re: What's Optimal Spark Advance for Our Engines?

To: <MG_TF1500@usa.com>, <mg-t@autox.team.net>
Subject: Re: What's Optimal Spark Advance for Our Engines?
From: "Ray McCrary" <spook01@home.com>
Date: Tue, 14 Sep 1999 10:49:20 -0500
Hello all,
Thought that I might take a stab at this.......

> Will some of you please share with the rest of us your thoughts on
> the optimal spark advance (in degrees of crank rotation)
> for our T-Series engines?
>
> How differently should this optimally be set for different compression
ratios?

I have some experience that suggests that the spark should be set so that
the engine pings (pinks) just a touch when the throttle is opened in top
gear with the revs at 1800 or so.

This amount will change depending on compression ratio, cam type, quality of
gasoline and shape of the combustion chamber, among other variables.  Then
back the timing off very slightly so that it just stops the ping.

This takes a little time, but works well with a sorta stock engine.
>
> At what RPM ought spark advance to peak, ideally?

Depends on how you use the car.  If you are a 'performance' kind of guy,
using the car on the road, full advance in by 2000 rpm will work well.  If
you tend to 'lug' the engine, maybe all in by 2800 would be best.


> Does the rate of change (or "curve") of spark advance matter much?

Yes, in a truly high performance engine.  These engines are sometimes even
set with the timing set in permanently.  In other words, all in at 0 rpm.

In these engines, unless you are racing, the stock setup will serve you
well.


Safety Fast!

Best Regards,

Ray


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