rrubel

Spent part of the weekend playing with DataMaster and my finally-readable early 86 (Thanks, Tequilaboy - your BIN works like a champ for scanning!) and I noticed that every time I revved the engine quickly I'd get a couple knock counts and spark retard. It's a loud engine (I set my wife's car alarm off while revving in the garage) and the knock sensor is just a microphone, but I wonder if I should be concerned. It's far from stock and higher-compression (I think 10.5:1 but don't have exact measurements) and I'm using 93 octane gas, but I'm still concerned. Premature detonation damage most likely due to a disconnected knock sensor (previous owner, not me) caused the demise of my first engine so I'm being cautious.

Any constructive thoughts welcome.

Thanks.
[RICHR]

mseven

I think as long as the sensor is working and removing timing it is fairly safe. Aside from the obvious detonation concerns you want 0 sparknocks, as when it takes away timing it also takes away performance.
I found spark knock can occour from instantly hitting a rich or lean place in the tune.Depending on the timing table, my thinking is to first get the fuel/air as close as possible first, then take away timing if needed (1/2 a degree goes a long way).

tequilaboy

Rich,

That bin has quite a bit of spark advance in the mid-load region similar to the stock bins and 36-38 degrees up top.

It may be too much spark for your heads and CR. Full knock retard is still available, so it can pull up to 20 degrees if required.

I'd suggest backing off on the main spark table if you can, as well as setting highway mode spark to zero, until you get an idea of where it wll run with only a few knock counts.

If you can't edit the bin, I can send another with considerably less advance for testing.

rrubel

Thanks for the new bin, Tequilaboy... I'll give that a try as soon as I can.
[RICHR]