Engine is 2056 with Raby 9550 Cam and D-jet
I have the stock Bosch plugs with factory gap
Running Pertronix with flamethrower coil
Engine timing is dead on the nuts
Valves adjusted 0 lash (chromoly with swivel feet)
AFR is 12-13 on the freeway
Fuel pressure is 30psi
Car runs great and has a lot of power all the way up to the redline. Engine runs very cool, seems to be happy. I have noticed that on a longer drive pushing higher rpms for extended runs there is a tiny bit of pinging unless i push down or let off the throttle, it goes away. I know that any ping even a teeny tiny ping is bad. SO...
I put Ultra Premium fuel instead of the midgrade and its still there. Keep in mind I might not hear it for a few days, but if I want to drive like I stole it for over an hour it can be heard.
I would rather not retard the timing from spec, and I dont want octane booster. So I was reasearching plugs and found that some new plugs might do the trick.
Question is do I want colder or hotter to cure my preignition. Is changing the plug my next step? A colder plug will help the preignition?
Joseph