Knocking under acceleration, help
 

when hot and under pretty hard acceleration my car will knock.
valve knock. timing is set to stock.
what should i try???

what octane fuel are you using?

Have you checked your head studs lately? Have you checked for exhaust leaks? Inspected your timing chain/tensioners lately? If your timing is set to 5 degrees BTDC, I do not see how it could be detonation. Many of us run at 35 degrees BTDC max advance at 6K RPMS, which is approx 10-12 degrees at idle. with no detonation issues...

im using super. just did a major service, no headstuds broken.
checked timing. im gonna double check the timing and advance function to be sure. thanks

Could be carbon buildup. Try a bottle of Techron.

thats a good idea, ill try that

It did the trick for me. I bought my 83 about 2.5 yrs ago. It did the very same thing. Hot, under hard accleration, knocked. I ran a couple bottles of Techron and no more knock. Also treat it to a bottle of Marvel Mystery Oil in the tank every now and then.

Did you move to a synthetic oil recently?

John

nope. i use castrol 20/50.

Make sure you have Castrol on hand....you'll need to do an oil change after running the Techron thru :)

One thing to check is total advance. On my '78 SC it would ping on accleration, the timing was good at idle. However I got something like 45 degrees advance at 4500 rpm. After taking out the distributor I found one of the advance springs had come off. After putting the spring back on (and a good cleaning) my pinging stoped.