Quote:
Originally Posted by frnkeore
One more question, related to this issue:
Does anyone drill the hollow lifters to lube the cam lobes? If so, what size do they make the hole?
Frank
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Do NOT drill a lifter that runs on a performance cam. It will shorten the life of both the cam and lifter. I am not sure why but I have seen several over the years that tried and failed and I have been in the cam business 65 years.
You do not to need pressure oiling to the lobes or lifters on a flathead street engine.
On my race engines, I drill the cam core and lobes for pressure because these engines have dry sump oiling with high vacuum in the crankcase. This tends to suck oil off of all internal surfaces that are not pressure fed.
After market cast iron cam cores for flathead Fords are very poor quality.
The hardness varies down the length. They work for the most part but they are still junk quality. (Do not send me any to grind)
Valve spring pressures are not critical on flathead street engines with cams lifting under .380. Anything between 60 and 80 on the seat will have a 6000 red line and NOT wear anything out prematurely, and that is with no titanium valves or lightweight stock steel lifters.
I have seen quite a few wiped out lobes on flathead Ford cams over the years but they have usually been the result of broken springs or stuck valves, NOT from normal wear.
Hollow lifters DO run with oil inside on a wet sump engine. No additional holes needed in the lifter bore for oiling.
If you REALLY have to know what is going on with your valve train, leave the intake manifold OFF, hook the engine up to a variable speed electric motor and run it from idle to where the valves float while observing things with a strobotach. You will have to pre-educate yourself on exactly what to look for.