DANMAS@aol.com wrote:
> It is my understanding that the internal pressure relief valve is there to
> provide oil flow in the event of an extremely dirty filter. When this valve
> opens, oil bypasses the filter, and flows directly to the engine. It is
> better to have dirty oil flow than no flow at all. For us LBCers, who
> maintain our cars well, this should never happen, therefore, a pressure
> relief valve is not required! Am I wrong?
What am about to say is one of those "heard it somewhere
and it sounded reasonables"... there's your disclaimer du jour.
The pressure releif valve works as you say, but has another
use. The oil pump is driven via the engine of course, so it
turns at higher speeds with higher RPMs. At high RPMs, the oil
is being blown faster and faster through the filter.
Given that the filter element is a restriction, the pressure on
the DRIVEN side of the filter gets higher and higher, while
the filtered side of the filter gets less oil-per-rpm as the
resistance across the element increases.
The pressure relief valve is supposed to open at this time,
to allow oil to flow to the valuables as fast as required. Some
of the oil is unfiltered, but this isn't really a big deal,
since every bit of oil finds it's way through the filter many
times on a trip anyways.
Just what I heard...
--
.---------------------------------------Ottawa-Canada-GOSENSGO-----.
/ Trevor Boicey 1992 Celica GT 1975 MG Midget /
`----- tboicey@brit.ca ----------...and both are running today!--'
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