oil priming the car before every cold start?? silly idea?

[Dragon Humper]

Not a chance, I use 15w40 diesel oil and only see 6 bar when it is dead cold, 4 bar warm.



Jon.

[jimBNR32]

For reference, I run a JUN pump, acl bearings.
8-8.5bar cold.
5.5bar anything over 3k ish rpm when warm. nothing over 6bar up the rev range.
2-2.3bar warm idle, 15w50 motul 300v

[NismoS-tune]

Anyway, my 8bar + seems to line up with the other guys in the world using Tomei oil pumps (suck as Robby Ward from rips and others on SAU or GTROC). My poobaru sees a 110psi normally as does the GTiR so I'm sure the superior gtr (jkjk) has just as good of seals.

As for your lower pressure, the stock pump is lower pressure and lower flow so that could be the difference?

Anyway, maybe I had an issue. Either way, I'm just waiting on Tomei for feedback on my pressure. I run nearly tomei everything including tomei bearing clearance..

[Dragon Humper]

There are many books written about this subject and many theories, but some things are universal.....

Your engine will only consume the amount of oil flow it is set up to use, any more than that will only get bypassed and recycled to the sump. Tight brging clearances, head oil restrictors and BB turbo(s) means that standard volume is going to be enough, even at 9000rpm.

Large brging clearances, no restrictor and journal brging turbo(s) needs more volume and more pressure. The bigger the clearances the more pressure you need to maintain an equal amount of cushion between the journal and the brg. If the pressure is not enough the cushion will get a little thin right at the bottom of the brg.

It's a fine line between getting the oil flow you want through the brgings to get the cooling that you are looking for (that is the main reason for opening up the clearance) and turning the crank case into an uncontrollable oil frappe from windage. I still think more than 85 psi is too much.

Even though the smaller brgings in the RB vs, say, a small block Chevy, would need a bit more pressure to carry the huge load of big HP, they sure don't need it in the mains. An RB has 2 more mains than a typical V8 to spread the load out. The rods, on the other hand, need some help. After all, 120hp per hole is a lot of pressure on those little rod brgings. Do you need 100+ psi of oil to do that, with stock clearances?......maybe.




Jon.

[MarusGTR]

9 bar wasn't a typo. Sadly if it's wrong ten I'll have to get my pump shimmed for lower pressure, I got a tomei pump installed and that's what I got for pressure. I'm running tighter clearances too. My Pulsar sees over 100psi with a stock pump lol

I use 5-40 oil, maybe it's too thick? Lol

I assume you knew about the pressure relief valve that has way generally tight from A/M pump manufacturers? You have to release the pressure for your application. The pressure is high from factory just as a precaution that the pump will give adequate flow for the pressure loss made by any combination of accessories in your system (coolers, lines, etc). Humper is right, too much pressure isn't advantageous.

[xcye]

The fact that OEM N1 pump runs an 8bar relief valve let me believe 110psi pressure is not unusually high for a RB engine.

[MarusGTR]

The fact that OEM N1 pump runs an 8bar relief valve let me believe 110psi pressure is not unusually high for a RB engine.

Its not all that cut and dry. N1 is meant to have the same flow rate than OEM but with more head to compensate for accessory losses, likely through the use of an oil cooler. It's N1 because its meant for track use.

If you turn down the N1 pressure at the valve to get it at OEM pressure, lets say for stock RB application, theoretically you might lose pump efficiency and flow rate. A higher pressure head is meant to be spent through purposeful use.

Again like usual I'm grasping at straws here, but its details like these I'd probably lose a lot of time with if I'd end up with money to blueprint my engine.

[NismoS-tune]

I assume you knew about the pressure relief valve that has way generally tight from A/M pump manufacturers? You have to release the pressure for your application. The pressure is high from factory just as a precaution that the pump will give adequate flow for the pressure loss made by any combination of accessories in your system (coolers, lines, etc). Humper is right, too much pressure isn't advantageous.

I know it but payed the builder to set all that up since
I wouldn't know where to start for knowing the pressure.

I'll talk with tomei and see what they say, I'm Running their bearing clearances. My turbo kit has a built in oil feed reducer

[MarusGTR]

I know it but payed the builder to set all that up since
I wouldn't know where to start for knowing the pressure.

I'll talk with tomei and see what they say, I'm Running their bearing clearances. My turbo kit has a built in oil feed reducer

Well you're lucky since IIRC, the Tomei has the valve built externally right? No need to drop the pan, just tweak as you run the engine

[NismoS-tune]

My engine crank walked during break in last year. Along with with a cracked block and 8 months at the builder to get it back, ready for the dumpster, it's too late Now lol

Anyway, I though the factory setting on the tomei pump was the lowest pressure.

Where would I get shims for that?

[Dragon Humper]

I figured there would be no shims, which is kind of unfortunate because the only way to lower the pressure is to get a new spring.....if it even exists. One thing you could do is grind down the spring ends to reduce their length (just like they do at the time of manufacture). You can't grind too much off, but that could give you a bar of reduction.

This whole thing is really a total systems approach with the final piece the weight of oil you use. And to clarify, that 85psi limit I mentioned is full operating pressure, not the cold pressure. Cold can be up to 50 psi more than operating, something to be warry of if your operating pressure is 100+psi.




Jon.