In a message dated 96-06-17 13:05:23 EDT, you write:
>I have a question about setting the timing on my spitfire. According to my
>manual it is supposed to be set at 2 degrees ATDC. I find that if I advance
>it to 6-8 degrees BTDC, the car has more power. If I advance it any more
than
>this, I start to here a rattling in the motor. Somewere along the line I
>recall be told that over advanced timing is not good for the motor,
something
>to do with additional stress on the con-rod bearings? I know that you'll
burn
>up points faster, but since I have a crane igniton, I dont think thats a
>factor. Any pros and cons about this? Also I have the vacuum retard
>distributor which I'm not to sure about why this is used instead of a vacuum
>advance. Something to do with emissions maybe? OK guys, let me have it!
JersyA,
The car was set up at 2 degrees ATDC to improve emissions not performance. By
advancing the timing, you're allowing the spark to ignite the air/fuel
mixture earlier, therefore allowing more complete combustion and more power.
That's fine up to a point, i.e. pre-ignition, or pinging. The louder it gets
the more damage you're doing - uneven crank loads and holed pistons. Timing
advance shouldn't have anything to do with burning points.
To reiterate the old method for timing lbcs is to keep advancing the timing
until pinging is heard, then back off 2 degrees.
Charlie B.
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