Thread: Detonated Dreams

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I've been reading posts on here for a long time without being a member. A lot of knowledge in this place. I am hoping to reap the rewards of all of your hard work now HA HA.

I have a 383 in a 63 Nova SS with a built 700r4 and 3.73 posi. The engine has a detonation problem that i haven't been able to succesfully get rid of so i now have the engine apart.....again. I am completely prepared to do what it takes so i can stop "babying" the throttle. This thing needs to be hammered on. The engine is as follows:

-4.030" bore
-3.75" stroke
-5.7" rod
-2 valve relief, flat top, hypereutectic pistons
-cast chevy heads, 441. They've been surfaced so they measure 73cc's now
-Crane Cam, installed "strait up", grind #H-272-2, .454/.480 lift, 216/228 dur (w 1.5 rockers, but i'm running 1.6 roller tips. Problem?)
-When my piston is @TDC my distance from the deck to the piston measures
.012"(is that the right measurement for deck clearance?)
-My static compression checks out to 9.83:1
-Dynamic Compression Calculates to 8.686
-Intake is a first gen Edelbrock ProFlo EFI, 4 valve, w what is essentially a performer rpm intake i believe.

Under cool temperatures, before the engine compartment gets toasty, i can run pretty hard. As soon as the intake temp gets up anywhere above "brisk" it knocks like a little baby. I've got the spark dialed back ALL THE WAY and the fuel turned WAYYYY up for the Load/RPM range that is killing me(less than 6"/2500-4000rpm). I can not ditch the knock.

I always run 91 octane or higher, if available. I've mixed a tank with 2 gallons of 103 and made some headway. In no way is this engine fast enough to warrant the need for race gas. I've heard that some things can happen to make your engine "see cylinder pressure" that rivals that of 11:1 even though you are only at 9.5:1. Not sure i understand how that would happen or what to do about it but i am VERY open minded at this point.

Any suggestions?