I recently purchased a 86 z28 camaro. the kid before me installed a rebuilt 350. runs starts and everything but there seems to be a knocking sound at idle and during acceleration. He said if i get it tuned and timed right it should go away. i was wondering if hes right or pulling my leg and have a bigger problem. It is not a stock motor, has comp cam, 305 heads, edelbrock carb headers. msd ignition. it used to be a 305 tpi. any help would be apprecciated.


Thanks
Justin

 

You can use a tube to listen to the engine; be careful & rest it on the engine to hear/help locate source of the knock. water pump? belt on way too tight around water pump or other accessory? something else?

 

Can you take a video and post it for us? What is the oil pressure at idle? The noise is actually there at idle? Does it increase with rpms and pick up speed? Describe it in as much detail as possible.. Also am I correct in assuming that it's carbed with a vaccum advance dist?

 

il get a vid on it as soon as possible. it is a carb with a vac. the oil pressure seems to be perfect at idle. its barely there at idle as u accelerlate it gets loader, i can still feel the car pull just i know it has wayyyyy more. I just did an oil change, i am not positive but i think it got worse when i did it

 

A typical problem would be trash in a hydrulic lifter, you would be able to isolate the knocking to the specific lifter easily with a peice of tubing or long screwdriver up to your ear.

 

try to retard the timing a hair at a time to see if the sound goes away. I had the same problem today.

 

are you sure the belts aren't set too tight by the previous owner? it can cause the exact same symptoms