Haven't post much lately, so heres a question.



I have a rotor pump, before I did any modification to it, at idle, I get about 10psi, 30-40 at cruise, I think thats within specs from the factory service manual, but I think its a little low, so I put a bunch of washers between the nut and the spring of the oil pressure regulator valve on the oil pump, now it idles at 25psi hot and 55-60 psi cruising.



but the thing is, with the washers in there, it limits travel of the regulator piston, I dont know if it will affact anything, but so far I haven;t have any problems.



what oil pressure you guys have in you Ys? do you guys think that 25psi at idle and 60 at cruise is overkill for these engine? is there any high pressure springs out there that will fit the rotor pump instead of putting shims and washer in it?

Ted,



If the roadster is only making 70# hot pressure at redline, what's the point of shimming the spring to bypass at 90#? Faster warm-up by friction-heating of the oil?

6 VOLTS/POS. GRD. NW INDIANA

The oil viscosity changes with the temperature.  Oil pressure is defined as 'resistance to flow' and cold oil simply has more resistance than hot oil due to being higher in viscosity.  When shimming the oil pump so it had 90 lbs cold, I was insuring that the highest possible oil pressure was 90 psi.  If I were to increase the viscosity of the oil being used or run the oil at a cooler temperature, then I could potentially have the oil pressure closer to 90 psi going through the traps than the aforementioned 70+ lbs.  If I had not shimmed the oil relief valve spring, then the oil pressure going through the traps was potentially going to be no more than 55 psi or whatever the stock spring tension allowed.

Lorena, Texas (South of Waco)