Mystery knocking

[MrSony]

If it only knocks when engine is at temp it could very well be carbon knock as pontiacgp said. You can use water down the carb (look up a vid how to do it, too much and you'll hydro lock your motor) you can also do it with ATF if you want to kill all the bugs for a 50 mile radius 😛

 

[Antonio Briscoe]

ok..so i pulled off the valve covers and have discovered that im not getting any oil to the top end...and i put a new oil pump on when i replaced the bearings so...what's the next move ???

 

[pontiacgp]

ok..so i pulled off the valve covers and have discovered that im not getting any oil to the top end...and i put a new oil pump on when i replaced the bearings so...what's the next move ???

it you were getting no oil to the top the valve train would sound like a sewing machine and that would be evident without removing the valve cover but you never mentioned any valve train noise. What oil pressure do you have with the engine at idle?

 

[Antonio Briscoe]

Ok so im thinking it was my lifters making the noise,so im in the market for a cam and lifter set.Now im am confused on all the numbers as far as lift and duration,so if some one could help me with like what i should be looking for...now im not racing the car or anything but i want a little more than stock specs. Thanks in advance

 

[Texas82GP]

We need much more detail on your setup. The more detail the better. Compression ratio, heads, intake, carb, headers or manifolds, exhaust, rear gear ratio, torque converter stall. Since its a 76 Olds 350 as you stated before, hopefully one of the Olds experts will chime in with a cam recommendation.

 

[64nailhead]

Ok so im thinking it was my lifters making the noise,so im in the market for a cam and lifter set.Now im am confused on all the numbers as far as lift and duration,so if some one could help me with like what i should be looking for...now im not racing the car or anything but i want a little more than stock specs. Thanks in advance

You are thinking it was your lifters?? But you were thinking it was the bearings, but it wasn't. You said you aren't getting oil to the top side of the valve train, but a set of lifters and a cam aren't going to resolve that. So, if you put a cam and lifters init and it's still making noise then what?

Here's my advice, find the noise before buying/changing any more parts. The oiling problem is probably at the root of the problem.

If you think it's a bad lifter, then start the engine and get it warm until it starts making noise, then pull both valve covers and push on all of the rockers at the pushrod side checking for any lifter that will compress and any rocker that is loose. Then spin the crank over 360 degrees by hand and repeat. The lifter should not leak down that quickly and any loose rockers need to be adjusted or you need a cam. At this point I would pull the intake and lifters before I bought anything.

But once it got to making the noise you should remove the belts to see if the noise is still present, then proceed with ^^^^.

Some other things to check - distributor shaft and gear, header/exhaust manifold gasket, fuel pump and pushrod (mentioned previously), rocker and ball, timing chain/gears, loose/broken balancer (mentioned previously), flexplate, transmission.

My two cents and hope it's minor.