If you hear the valve train squeaking and/or clacking, then pull the covers. If the valve spring area is not wet with oil, it’s probably not oiling. When running the engine with the covers off, you should see oil dripping from the sides of the rockers. If you have small piles of metal residing under the rocker assemblies, you’ve likely gone too far with no oil. Those are the simple clues to ‘no oiling’.
Rono has mentioned the shafts being installed incorrectly and that’s the number one reason for lack of oil to the rockers. The shafts can be installed in one of four positions and only one position will provide oil to the rockers. Using the overflow tubes as originally designed typically prevents the shafts from being installed incorrectly but if the overflow tubes have been modified or damaged, then a rocker shaft can be installed incorrectly or have even clocked itself away from the oil galley hole in the head.
Spinning the engine over with the rocker assembly off should at least have an oil flow out of the head at the second from the right rocker stand support. If no oil, then you’ll have to dig deeper. A poor vat job on the block during the rebuild could have potentially left the oil galley plugged which will be reasonably easy to fix with the cylinder head off. Beyond that, it becomes a cam bearing issue.’
If there is a ‘soft’ cam bearing issue present, then it invariably shows up on the right bank first. In this case, the soft babitt in the replacement bearing pushes itself into the groove in the center camshaft journal and pinches off the oil supply to the topend. The physics behind this has the oil supply to the right side of the engine shutting off first. On the inferior bearings, this happens reasonably quickly on a new rebuild and has happened in as little as twenty minutes or as long as 250 miles depending upon the valve spring pressure that’s being applied.
The ideal fix for this is to simply replace the cam bearings with a ‘harder’bearing set but a longer term fix is to modify the oiling system so that any compression of the center cam bearing is no longer an issue. There are several fixes for this during the engine rebuilding process which includes 1.) machining the camshaft groove deeper, 2.) using a center cam bearing with an outer groove to bypass the cam groove for oiling purposes, or 3.) machining the center cam hole in the block with a groove to give a new oil route to the topend.
Lorena, Texas (South of Waco)