I put a fresh 455 olds Into my 56 Olds. rebuilt C Heads a fairly mild Lunati Cam (think performer RPM). I did not confirm the oil galley plug at the back of the block, Or that it had the tiny hole in it (an Olds Thing) There was a little flash rust in a lifter bore... the lifter went in but it was a little tight. Upon fire up, that lifter never pumped up, so i tore the Intake off and changed that lifter... the Cam looked good, so did the new pushrod and the new rocker assembly. NOW the same lifter is having problems...so... I am thinking the lifter is an effect not the cause. Is sounds OK at 25 mph (under 1500 rpm) but over that say 45 mph the lifter seem to collapse, hard throttle it collapses, after a a block at 25 it seems to quiet down. Seafoam helped a bit but didn't cure it. I really don't want to pull it back out, but I think i may have to. any ideas?
Souns like a little piece of crud may have ended up in the lifter oil supply holes during the rebuild
are you sure it is the lifter? olds seemto have lowoil pressure to the top end and the pushrods are known to plug causing the rockers to wear on the aluminum rocker stands causing wear and "lifter" noise.
to clarify, its #7 exhaust side, all the rockers are new. I will pull the valve cover and look for oil squirt... good idea Don.
OK Valvecover off ran for about 3 minutes mostly Idling a few blips to around 1000 rpm. Oil barely oozes out of the rockers on the left bank, after 3 min nothing still out to #7, intake or exhaust. I'm thinking bad pump or missing galley plug ?? but it looks like the motor is coming out. Poop!