Phil----Glad you had fun by taking the TR on this trip. (Most of us knew
you would)
You didn't mention what viscosity of oil you use in your '73. The 35-40
psi is a little low IF you were using 20W-50. Clean, undiluted oil tends
to raise the pressure about 5 lb. or so, no matter the blend. Long runs
at highway speeds does lower the oil pressure. You've noticed that
coolant temperature alone doesn't do much in stabilizing the pressure.
My personal experience is that "runs" like you just had should show
gauge pressure in the 65-70 lb. area when using 20W-50 oil, and the
crank and rod bearings are still in good condition. When my engine had
73,000+ non-overhauled miles on it the oil pressure hung around 50 lb.
when fully warmed as yours was. At idle it would drop to what looked to
be about 7 lb. 6 oz. of STP oil would bring it up a little. If the
engine doesn't knock and use much oil, you should be safe for another
25,000 before considering major repairs.
If you're up for this sort of thing, sometimes new bearings along the
crank and rods will bring up the pressure quite a bit if the journals
are still smooth. It sounds as if something needs attention in the
starter area first!
Dick T.
'73
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