In article >,
"Mal Osborne" > wrote:

> Does this mean you need to use higher octane fuel to avoid pinging?

Maybe; 14BTDC is near the edge for 87 octane fuel, and whether it will
ping will depend on manufacturing tolerances, intake temperature, and
carbon buildup. At 14, my car used to ping on 87 above 60 degrees F
ambient, and on 89 above 80F. A Randall cowl intake tube now lets me run
87 year round, with no pinging up to at least 104F. It should pay for
itself in, oh, about 143 years...

> With older pre-EFI cars I have always tuned timing to just below
> where I star to hear pinging.

Same here, usually around 10 degrees more advanced than the factory
setting. But when ECU ignition maps replaced vacuum and centrifugal
distributor advances, that stopped working. The "new" way is much, much
better!

---
Lanny Chambers
'94C, St. Louis
http://www.hummingbirds.net/alignment.html