78 SC timing question
 

78 SC has upgraded Euro pistons, raising compression fron 8.5 to 9.5. Should the timing be changed ? stock is 5 BTDC@1000 and 25@6000.

Any help is appreciated

Steve larson
84 Cab

You're in the ballpark; maybe 30 degrees @6000. I'd suggest putting it on a chassis dyno and check/adjust for near optimum advance throughout the rpm range; fuel mixture too. You want to maximize the ign. timing while staying away from borderline detonation under any condition (lugging doesn't count).

Sherwood Lee
http://members.rennlist.org/911pcars