Talk about engine building here. New products, tricky questions or showcase your work - If it's engine building related it's welcome here.
I'm thinking of putting a supertec spline drive oil pump in my rb30 (same as 20/25/26). The kit contains the innner and outer ring of the oil pump and a crank collar with splines (like toyota oem has). I have an original pump now (81mm).
My question is : should i put the new gears in the oem pump(81mm) or should i put gears in a N1 pump (78mm) ? The gears are not cheap so i need to be sure before ordering.
My engine will keep stock head (rb25 spec 1) , slightly more clearance on the bearings. and a ball bearing gt3582r.
The difference between the N1 and OE pump is that the N1 pump provides more oil volume flow but this is to do with the design of the gears themselves rather than the diameter. What i mean is that these differences will be affected much more by what Supertec do with the replacement gear than the actual diameter of the housing. I would be inclined to stick with your factory housing assuming it is in good condition as it will save you the cost of buying an N1 pump just to dump the N1 gears.
Like Andre said - it all depends on the actual condition of your pump, how much it ran already.
Here in my place not much mehanics can and do check is oil pump ok, so i always advice to replace it when building performance build. If you trust your mehanic as him to dissasemble your pump and check its condition, but since N1 pumps got cheaper these days i believe it can be cheaper to buy new n1 pump to start with than to diagnose and correct some minor problems i believe every old pump has.
I am my own mechanic, so i can confirm my pump is in good shape. Just want to check opion with people here having more expience.
so i'll stick with the stock pump.