Hotdog1958

I just bolted in a new, LS 364/440 - it has flat-top pistons with 10.9:1 compression -.500/.500" lift cam, Holley 770 street avenger carb in my 69' Camaro. Brand new, crate motor from GM performance.

With a Trimec 5 speed manual trans, 4th gear on fwy 70 mph is about 3000 rpm, and 5th gear @ 70 mph is about 2000 rpm

Problem is I'm getting pre-detonation when I step on it.

Today, I heard its probably the carb? Someone told me I'm starving it of fuel, and the carb choice was not correct? I don't want to damage the engine, it sure doesn't sound good and I can't be doing it any favors.

Any suggestions and direction would sure be appreciated.

bww3588

iTrader: (49)

Is the carb new? It may be a little on the small side. Either way, is your vacuum secondaris working properly? You might try fattening up the secondary circuit a little

Busted Knuckles

Never heard of pre-detonation. I've heard of detonation and pre-ignition but not pre-detonation.
Please explain, we're here to learn...

Hotdog1958

Detonation may be the term? it sounds like there are nuts and bolts rattling around in the combustion chamber!!

as I'm not a mechanic, although I basically installed the engine, tranny, rack n' pinion steering, and wired the entire car, I don't think I have the knowledge to track this down.

I'm in Los Angeles (South Bay, Near LAX, Santa Monica)
Any recommendations of someone who can look at this for me?

btw, all parts are new...

nhra686

take some timing out?