Hey, I have a new motor and I am trying to figure out some ping/knock issues. not sure if they are real or false. I have driven the car about 150 mi ish.. the plugs look ok I dont see any evidence of detonation but maybe its too early. I am wondering if the "stock" plug that brodix recommends is too hot for my application. The plug is a Autolite 3924. I wonder if I should go with a set of 3923's.
I am running a 355 with Brodix IK 180 heads .500 lift cam 224/224 10.2:1 ish compression and 8.3-8.4 dynamic TPI intake, ported edelbrock manifold with AS&M tubes 52mm throttle and shorty headers.

 

Plugs only need to be hot enough to burn the deposits off the plug. Too hot and they may start to melt the plugs. Too cold and they foul up. There is no right or wrong answer as to what heat range the plugs for your engine requires.

Plugs are cheap. Run the coldest plug possible that doesn't foul up.

A good heat range will have a temperature change line about half way up the ground strap.

 

Thanks for the reply. Im attaching a pic of the plug. Looks pertty good I suppose, but only has 150 mi ish.. I can see the temp change you refer to in the photo. I may still try the 1 step colder plugs. But now I need to determin what may be causing my knock, or causing false knock.

 

Temp line could be a little higher but it's close. One heat range colder should work.