Mike---Recheck the obvious, just in case...
Oil level on the dipstick, and dipstick marks correct.
Compare oil pressure readings with another gauge, taken right off the
port/ line to the dash gauge.
Did you have the crank reground as part of the engine rebuild? (Check
journal ODs and compare to what bearings were used.)
The fact that your oil light comes on when the engine oil gets up to
temp is not a good sign. 45 lb. at road speed is far too low, with just
about any oil viscosity. If the engine is truly low in pressure, then
try using Plastigage on all of the crank and rod bearings. It would
seem that the passages are too loose. It's symptomatic of an engine with
about .0035 bearing clearances.
Any history on the pump itself?
Dick
From:
mblunsfordsr@yahoo.com(michael lunsford)
I have just finished rebuilding my "fast street" engine. It runs great
but I am concerned about the oil pressure. I get about 85 psi at road
speed and about 45 at idle when the engine is cold. When it gets full
warm it goes down to about 45 at speed and 20 or less at idle. Sometimes
the low oil pressure light comes on at idle. Everything in the engine is
new, all bearings, oil pump and everything normally associated with oil
pressure. I just changed the oil and filter and the oil from 15-40 wt to
straight 35 wt (3 qts 30 and 3 of 40). It helped a little but not enough
for my liking. I swapped out the oil pressure relief valve with another
used one that a friend had that worked great for him and it was worse
than my original one. Anyone have any ideas before I drop the pan and
check the pump and bearings?
Mike Lunsford, 1970 TR 6
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