"No body" wrote in
>news: snipped-for-privacy@comcast.com:
>
>> Ok. I check it out again today and this time it topped out at just
>> over 45 PSI. That's what I'm used to seeing.
>>
>> I think mid 50's is kinda high. 7 more PSI and the needle is buried. >>
>>
>
>Hmmm.......maybe how the oiling system works isn't clear. The oiling
>system works by 'floating' the rods, and crank on a layer of pressurized
>oil. (Technically, a hydrodynamic bearing). I would be more concerned
>about lower pressure as opposed to higher. If the pressure between the
>bearing shell and the crank is not high enough to withstand the forces
>exerted, then contact is made between the two,
That's a misleading description of how it work as any mechanical engineer could tell you. The oil pressure is merely a means of providing oil to the bearings and other surfaces. A rod bearing has maybe two square inches of surface on the upper bearings so that is a
100lb force maximum seperating them as far as oil pressure is concerned. What prevents metal-to-metal contact is a wedge of oil produced by the movement between the two surfaces. THAT is what is able to withstand PSI forces in the thousands. The oil pressure is irrelevant as long as adequate oil is provided to replace what is thrown off. Think of the camshaft lobe/lifter interface. Typically the only lubrication is provided by splash or drip yet this interface surfaces very high unit pressure.Don
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with major bad consequenses in short order.
>The only time I would be concerned with high oil pressure is if it was
>WAY high, (say more than 150 PSI), indicating that something major is
>blocking oil flow.
>My truck runs 80-90 PSI cold, 50-60 hot both @ 2000 RPM. Manufacturer
>calls for at least 20 PSI @ 2000 RPM.