Change N1 Pump Oil Pressure

[sav man]

I know this is listed somwhere on SAU, but I can't find it. I want to drop the oil pressure to about 75psi in my N1 pump. Does anyone know what spring combos will do that?

[kitto]

If you've already got an external oil fitler/cooler. You could just add in an external oil pressure regulator. Only down fall is it needs a return back to the sump via say a -10 fitting.

[T04GTR]

why you would want to do that i dont know.. if so you may have to remove the shims in the relief valve. if its filling the rocker covers up that wont really help. but it would be a massive job for a "just to see"

[rob82]

why you would want to do that i dont know.. if so you may have to remove the shims in the relief valve. if its filling the rocker covers up that wont really help. but it would be a massive job for a "just to see"

Don't believe a standard n1 pump will have any shims in the pump. From memory it will just be the two springs. But I'm with t04gtr 75psi isn't overly high. What oil are you running? You could try a different weight.

[KiwiRS4T]

The N1 pump in my RB30 runs at 140psi cold and 100psi hot at 100km/hr and idles at about 50psi.

I am going to get a better oil pressure gauge to check but it does this with a couple of different grade of Motul that I have tried.

I also had problems with oil filling the cam covers (and blowing out everywhere) but this seems under control since I fitted 2 x 1mm restrictors and two breathers from the sump to a catch can (no "oil drain" from the back of the head).

[sav man]

the standard reliefe valve is about 120psi, it's no good. All the reliable RB's down here run ~75psi (that includes the 500rwkw lap record holder). But none of them run N1 pumps, so I can't get get a starting point for springs.

I had read somwhere that the N1 has two springs, but when I opened it up, only one big one was in there. I have put a fitting in my sump so I can change springs pretty easy.

[kitto]

140psi. Jesus. I am thinking of just fitting external pressure regulator after the pump so I can adjust it down if I need to.

[T04GTR]

and the down side of having high oil pressure? 100 psi at full noise hot is bang on. what is the problem with the engine?

you pressure reading is that taken from the small 1/8thnpt plug rearwood of the oil filter housing on the block?

oil pressure SHOULD be adjusted with oil wieght and bearing clearance, idealy there should be no presure relief in the pump ( aka most dry sump pump set-ups). so ALL the oil is being circulated removing heat and lubricating.

if you are concerned about the pressure try loosening up the oil clearance 1/2 a thou or so on the big ends. (try to keep the mains a little tighter so oil pressure rises quickly) also, having a high pressure means the oil pump is returning alot of oil to sump/pick up instead of going thru the bearings.

so opening up the clearances will make it live longer aswell. + reducing the oil pressure. 2 birds with one stone.