Originally Posted by Xgasser
I am stumped and hope someone can shed some light. I installed a SBC 350 that sat around for about 12 - 15 years and fired it up and had 65# of oil pressure. Everything seemed to be normal until I noticed there was no oil coming out of the rockers. I pulled the right bank pushrods and rockers to blow them out and noticed there was oil in the pushrods - most were clean. The hyd. lifters pumped up and I watched the pushrods rotate while cranking engine over. I even ran it for about 20 minutes by manually oiling the rockers to no avail. I substituted another distributor thinking the base may be too small and oil leaking by there - never started it but just cranked it and watched the rockers - nada! Doubt all the lifters went bad sitting and thought if the oil galley was blocked, at least some oil would come out of some of the rockers. Any ideas???
Thanks in advance, Stumped
The lifters have a metering plate just under the pushrod cup, whether passages or bleed holes or both (several design approaches are used depending on the manufacturer) are very small and easily plugged. Oil left to sit actually will resin cure or the passages/holes became plugged with suspended dirt that settled.
With care these can be cleaned. The lifter body does not need to be removed just the inner plunger. Remove the bail from the top of the lifter after removing the push rod. Take the plunger out putting it on a clean towel take the top apart (remove the push rod cup) typically there will be a disk with 1 to several tiny holes in it. The bottom of the push rod cup typically has a very small protrusion that the dist seats upon this may have an equally small passage in its side. Inspect all of this under magnification and clean carefully with a solvent like lacquer thinner. If there is a wear pattern in the disk reassemble it in the reverse position so any wear faces into the plunger's reservoir. Lubricate the parts with fresh oil and install them back into the lifter body they came out of.
This process leaves the lobe and lifter match intact, but you must be careful not to mix internal parts of the lifters as well.