Temp. and valve clearance
 

Yesterday had the best drive I've had in months. Decent low end torque, Solid exhaust BBRRRAAAKKK ... up through the gears and no pre ignition ping going up hills. Did I mention the temperature was between 45 F and 60 F ....
The engine was rebuilt last year and runs well but alot better when the air temp is low. I've played around with everything and it has much lower power and engine ping ... anytime the air temp is above about 75 f.
Anybody know if valve clearance could be the solution? Maybe a looser setting when expecting higher engine temperature? BTW ... drove this car last winter with temp around 20f and it really flew! Maybe it just loves cold air.
JIm in Ma.

You running Solex or Weber carbs?

Hi Darryl ... Weber