hunter51190

hi i have a 1976 chevy camero with a 350. The motor has a elbrock 600cfm carb, elbrock performer intake, branded new ported 202 heads, thumpr camshaft, stock bottom end as fare as i no. Just put my top end together and i am having a bad pinging problem under load between 1000 to 3000 rpm, i tried 91 octane gas, i richened up my carb and i advancted the timing. Nothing seems to work, can anyone help? do i need more octane? i am running a 476 lift cam and know i am ok on clearance, also it only does it once the engine is a full heat which i am running a 185.can anyone help?

72c10gunn

try a colder spark plug, i would retard the timing rather than advance it....try the timing first and if that doesnt work try plugs....have u done a compresin test to see what your cranking compresion is?

hunter51190

I haven't, I wanna try to leave the timing advanced as much as possible because I get much more performance out of it. It has much better reaction and get up and go advanced. Could the valves need adjusted again after I put the came in and ran it?

maxxman04

problem is you'll get the pinging if timing is advanced too far. yeah, you'll get a bit more power, but you do run the risk of grenading a piston, maybe. and of course, the pinging.

hunter51190

thank you, I will try this. I had the feeling that was why, but before when u had a smaller cam I had it very advanced so I didn't think that was it, but with a 476 lift it must just me enough to hit. Thanks everyone

72c10gunn

wait pinging is caused from predetanation....either too much timing and/or too much compression for what fuel ur using....if you have valve clearance problems then thats a diffrent problem. the bigger cam should have made it less likely to ping than the smaller cam....