are there any differences between the s1 and s2 onwards buick oil pumps other then the stronger bypass spring on the s2 that increases max oil pressure from 50psi (s1) to 60psi (s2 onwards). i want to make sure i've got heaps of oil pressure before i subject it to a shot of nitrous. i'll be fitting a new timing chain most likely to ensure accurate cam timing and will obviously have the cover of so can do the oil pump at the same time if required cheers
i have and it's as it should be (for a s1 engine) but i want more oil pressure as cheap insurance and my gregories says the s2 engines have more oil presure s1 max pressure 50psi minimum pressure 40psi @ 1850rpm (operating temp) pressure relief spring = 64.8mm s2 max pressure 60psi minimum pressure 55psi@ 1850rpm (operating temp) pressure releif spring = 66.3mm so the relief spring is definitly longer resulting in the increase in max pressure, however the s2 minimum pressure is 15psi more at the same RPM and that wouldn't be related to the presure relief spring. i'm guessing that there must be some sort of difference between the 2 pumps? just wondering if anybody knows?
My guess would be that the driven gears are different on the higher pressure unit, to create higher pressure the volume that the pump moves out has to be higher. Other alternative would be its for a different viscosity oil, but probably not. One concern is that I would never put my house on anything written in the Gregory's manuals........they have been wrong before(dangerously wrong)...........
there is that. also consulting a haynes manaul including VS all except 1991 VN series 275kpa (40psi) warm 1991 VN series 375kpa (55psi) warm however i can't find any mention of the max pressure for either or what the pressure releif spring lenght should be???? i guess maybe fitting a presure releif spring for a 1991 VN and see what it does is the easiest option. i am certain that the later model does have the increased max pressure however if you read it as per the haynes it suggests that the later models (V6 upto 1998 covered by the same manual) actaully run the lower pressure again???? odd
im pretty sure that the springs are interchangeable..like most places will just sell ya the series 2 spring anyway..as far as i know and herd the spring was mad bigger to make the pressure higher and are interchangeable with series 1....the timeing cover is not however as it has different coolent passagees or something
