I am running approx. 10.5:1 compression on a 388 motor with Super ram setup. The cam is a 222/230 .509 .528 LSA112. My car pings above 4000 rpm. I took the timing gun to the car and it read 45 degress at 2500 rpm. I have iron heads that are 64cc that were shaved. They are probably like 63 or 62cc. These are the camel hump heads. They are 2.05/1.60. Is this compression ratio too high for the street. I've used octane boost along with 93 octane gas and it still pings like crazy. I can't retart the timing anymore because it runs like crap then. Do I need new heads?

 

That comprssion ratio is high for steel (fuelie) heads on pump gas. What is the quench height? I am assuming that you are not turning the distributor to retard the timing.....and doing it the right way be repromming the chip. Just moving the distributor around won't help because the ECM will mess things up. It is a TPI car, right?
I would reprogram the chip with less timing a little before 2500 rpm, or you might try adding fuel before 2500 rpm. I would try adding fuel first.
Cheers,
J

 

This is a speed density TPI. I had the chip reburned by ed wright because I was experiencing the problem before. Its not as bad as it was before but its still not gone. I'm not sure what the quench height is. If you are talking about intake runner size, I wouldn't know. The casting number is 3991492 if that helps you.

 

Ed Wright loves to put lots of timing in his chips. Tell him to take out 2-4 degrees at the higher rpms. I had to send my chip back like 4 times before he got it right, and it still ain't right, so I'm burning my own now.

Your initial timing also has an effect, try retarding it and using a scanner to see when and where you are getting knock.

 

The quench height is the distance between the top of the piston @ TDC and the flat part of the cyl. head chamber. You want it less than .040" to minimize detonation. Since the motor is already built, the only way I know to remove the ping is to add fuel (cooling) or retard the timing (reduce cyl. pressure). Both have to be done by modifying the PROM unfortunately.
J