Need help, got a knock.

84 Camaro 400ci. 5 speed manual. Just rebuilt the motor, now got a knock. Oil pressure is good  at idle and under power. Checked lifters, rockers and pushrods. The knock is not there at idle, 2000 rpm and higher. Also gets louder as rpm gets higher. Used a stethascope and cant locate the noise. Anybody have a idea as to troubleshooting the noise? Also does it when motor is cold or hot.
Thanks Quigley  

Wrist pin. Knock forever and never affect oil pressure.  

I'm new to this, and don't know just where to post a question. i'd like to build a 350 for my '86 GMC 1/2 ton truck (700R4, 3.43 gears, and 33's. It's just a daily driver but I would like torque to get ol' high-gears down the road). Any suggestions as to heads/cam/compression/rod length/intake/carbueration combo????? I'm getting about a dozen different ideas from buddies and I just want a strong daily driver.  

Is there a way to tell if it is the wrist pin?
Thanks Quigley  

I think I have it narrowed down to either the #6 or #8 cylinder top end. Is there any way I can tell if the lifter is bad without taking it out?
Thanks Quigley  

Pull the valve cover on that side and have a buddy start the car, while you look for differences in rocker movement. A noisy lifter, or valve adj. should be as apparent at idle as would be anywhere else in the RPM's. Your  senses are your best tools for trouble-shooting. For example, valvetrain noises happen at half engine speed. Crank, rods and piston noises happen at direct engine speed. While you watch the balancer, determine if it is one or the other. To narrow down a suspect piston, rod or bearing problem on a specific cylinder, pull the plug wire on that suspect cylinder and listen for change in sound, besides obvious engine miss and idle reduction. When you take it for a ride, does it make more noise under acceleration, deceleration, or steady cruise? After these test, when you have located the problem cylinder(s), or events when sound is most apparent, post your results and I take you further in the troubleshoot, based on your findings.  JW.  

With valve covers off and motor running there is no obvious difference in any of the rockers. Pulling the plug wires while the engine is running again no difference in the sound. The knock is more noticable while under deceleration and cruise. No knock at idle runs quiet. When rpm reaches about 2000 rpm starts to knock and gets louder as rpm goes up. Sounds like #6 or #8 cyl top valve train. Oil pressure is good both idle and cruise. Compression is 150 to 155 on all cylinders. Cant pin point with a stethoscope. Thank you for all the help so far, this is driving me nuts.
Quigley  

When the valve covers were off, did you verify if the sound was half engine speed (cam), or crank speed?  

Not sure what you mean. If you can explain how to do that I will pull the valve cover and try it.
Quigley  

It sounds more like timing. If the timing is too advanced the timing at higher rpms will not fire the volt in the spark plug in time to spark the gas before it pre ignites. Also, have you changed the advance springs in your distributor? If you did you might have changed them to the springs that are too tight which stops the engine from retarding the timing to keep up with the engine speed. Other things you can check for if you do go to the heads are..... valve lash, coil binding, collision from the piston head, or maybe even a loose valve guide.  

Did you rebuild the engine yourself? If so tell me the specifics on the internals. Make shure you include all cam specs, piston's used, rod lenght, base and total timing, heads and head gasket thickness, and anything else you can think of. I had thought about the valve hitting the piston, but did not persue the idea because it is still running ok, but to narrow the problem we have to establish if the sound is crank speed or cam speed. I dont think it's timing because he says it's loudest on decceleration. Mark an easy to see line on the balancer and as the engine is running watch your mark. If the sound is happening at crank speed, it will have a same time rythem as the mark passes. If at cam speed, it will sound every other time.  

Replaced bearings, rings, cam, lifters and pushrods. New oil pump and screen. Used the old pistons and rods. Nothing was done to the heads. same size cam as before, dont have the specs handy at the moment. I will try to determine the speed of the noise and post back. Thanks again for the help.
Quigley  

One thing I did not ask was, did it knock when you first fired it or after some miles?  

Soon as it fired.
Quigley  

When you changed the oil pump, did you switch to a high volume? What pump driveshaft did you use? If it was the stock shaft with the plastic coupler, I would check it. What is the condition of the distributor? Any play in the shaft? How is the gear, ( teeth and shaft coupler)?