this may seem like a dumb question. but i am running 93 octane exxon fuel. i put my engine together and it is supposed to be 10.5:1 compression.. the engine builder said 92-93 octane was fine... i would not have to worry about running race fuel. but now im getting a lot of valve chatter when i log on it in 3rd gear and up. so any words of wisdome?
that "valve chatter" is probably detonation... 10.5:1 could work with aluminum heads... I think the LS1's come w/ that from the factory. but they have a really good chamber design. what heads/pistons are you running? how much total timing are you running?
Put a timing light on it and read where your advance is running. Double check your roller rockers also. You are no where near detonation due to compression problems. Sounds like an advance problem. Have you played with the fuel pressure?
my buddy that set the timming had it a little off. he was adjusting it by the notch in the timmingindicatorand not the edge... i set it at 10* by the edge of the timming mark... and it sounds fine now... the fuel is at 42# at idle wit hvacumm hose on..