Originally Posted by
Rrumbler
The drain back holes in the valley are between the lifter bosses on Gen I blocks (on Gen II "roller" blocks, they are different, but cam lobe oiling is not so much of an issue on a roller if good assembly techniques are followed). When the oil from static priming, eg. with a drill motor, runs down the pushrods and seeps out around the top of the lifters and the bosses, it runs back through the holes, down the lifter bosses under the web, and down the lifter body to the cam lobes. In operation, yes, the primary lubrication of the cam lobes is from splash/mist, but for pre-startup, the combination of the high pressure lube and the oil from static priming should be sufficient that the risk of galling on starting should not be a concern.
In my early wrench years, the gentleman I shadowed taught me that slowly rotating a fresh engine, while static oiling, distributed the oil around the bearings, the better to provide protection during initial start, even though the bearings had been oiled by hand during assembly, and we never talked about camshaft lubrication; it seemed it was a given, what with the assembly lube and oil that got onto the cam from priming.
Agreed, I would not install any flat tappet cam without a thorough coat of camshaft assembly lube, and I would limit the amount of rotation of the crank to only two complete turns - rotates the camshaft only once.
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