I have just rebuilt a 350 engine for my truck. The bottom end was done at a machine shop. Heads,push rods, roller rocker arms, intake, valve covers were installed by myself.

the problem I'm having is when I turn the engine on to break it in, theres a loud banging/knocking noise coming from the engine. It's more then a loose or sticky rocker arm ticking. The noise does increase as rpm goes up. I checked the PSI (compression) on it and the #2 cylinder has about 175 to 180psi compared to all others at a 150psi. Also the header tube on the #1 cylinder is cold when all others are warm/hot.When checking all the plugs they all have signs of ignition.

I'm not sure what it could be right now, either a bend push rod or maybe the rocker arms could be hitting the valve cover's which are aluminum so it might make a louder noise but it definatly sounds like metal on metal contact somewhere. Any help or ideas would be great!!!

 

Did you adjust the rockers??

 

Well Im sure you thought of running it with the valve covers off. Let us know how that goes.

 

Took me a while but through trial and error i got it. I forgot to mention that the truck used to be a one piece rear main, and is now a two piece. With that comes the larger end on the crank and the bugger was bashing off of my tranny inspection cover. As for the compression issue i readjusted the rockers and that seemed to even everything out. Also after close inspection of the dist cap the no1 prong was lose. Luckily it's 2 days old and i switched it under warranty. Thanks alot for the suggestions though.