what _IS_ a good cruise A:F ??

[Chief]

At 05:58 AM 4/8/97 -0700, you wrote:
>Hmm, someone that seems to know a lot about the 350 (good).  Mabye you can
>help, my 350 is set up with 4 deg static advance and it uses the Accel blue
>advance springs in a HEI dizzy.  Yet, it still sounds like a machine gun if
>you go wot when engine temp is as low as 85deg cel.  I have thought of
>running a 170F or 160F thermostat to run cooler (180F fitted) but haven't
>had time yet (doesn't ping when semi-warm 75C).  The next move is also to do
>a compression test to see what its like, it had normal flat top pistons put
>in when I built it (but who knows how much the machine shop took of the iron
>heads).  Anyway, what sort of compression PSI am I looking for ?  By, the
>way I run pump leaded (95oct, have thought of trying BP100). I also run
>standard plugs at 0.05" (could they be too hot ?, too big a gap ?).  Where
>do I start ?
>
>Dan     dzorde at geocities.com

My $.02 worth.

The max street gap most people use is 0.045".  You can use a bigger gap but
it is understood that coil longevity will suffer and will not promote better
combustion.

It sounds like your advance curve is goofed up and you have too much advance
at WOT.  It would be useful to get some timing tape for the crank and use a
timing light to check the timing from idle up to redline.

They probably just cleaned up the heads.  They would have to shave them
quite a bit to change your compression dramatically to where it might a
problem.  If you had a compression ratio problem, it would tend to ping at
lower rpms also.

I don't think a compression test will help diagnose your "machine gun"
problem.  It will give you an idea of what shape the engine is in though.

Ed Hilker aka "Chief"
84'SS - 700R4