Cringe is right!
But you know what?those boys kept coming back for more. And I kept giving it to them. To me it was ordinary. Can you imagine the stories those guys are telling! My younger brother was along occasionally. His memories of terror are not at all the same as mine.
Multiple chunks is what I have accumulated; almost everything from 2.76s to 4.30s. plus a 5.13 and a couple of 4.89s.
MOPEkid
I did a little math on your set up. I assumed ramps totalling 45* for your cam, and ground on a 112CL. That makes your cam advertised at about; 258/266. If it was installed about straight up, that would put the intake closing angle at about 59*ABDC. And that would make a 10.5Scr chamber into a 8.72Dcr motor.
Now, if that's anywhere near accurate, yes 8.72 with iron heads is apt to"ping".
If it does so on Premium, then it would be prudent to make a change. However, if you care to; a change to your cam timing might be all you need if your case is borderline. Retarding your cam just 5*, might put The Dcr to 8.4, which might get you out of "ping",with Premium.
And bear in mind, the engine only needs enough octane to suppress detonation under it's maximum loaded condition. During putting around and hi-way cruising it might only require 87 octane or even less. A lot less. Furthermore if it's not "pinging at WOT, then slowing down the rate of advance so that the all-in timing is a couple of hundred rpm later, may get it out of trouble.
Another thing that can help is to kick the Vacuum advance out a little sooner. You know those cans are adjustable through the nipple, right?
And if the cam was installed at the typical 4* advanced, then giving up 5* of cam timing; you probably wont even notice.Except for the diminishement or elimination of the "ping".Yeah I know it's a PITA job, but it's easy and super cheap. Good luck.
