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Rb30 Idling Oil Pressure

Hunky

By Hunky,
in Engines & Forced Induction

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Hunky Explorer

Hunky

Posted
Posted

Just had a few concerns about my oil pressure on my rb30det, sometimes if I was to sit at traffic lights my oil pressure on my dash would go down to 0 (the red light never came on) but I read that the factory gauges are notorious for failing, so I installed an aftermarket one. Unless it is reving at 1200-1400rpm the aftermarket gauge does not see any oil pressure. Driving is fine get at least 10psi per 1000 rpm if not more, but idling I get virtually nothing,

I am running factory rb30 pump with 2x 6mm spring washers as shims.

What can I do to Bring pressure up ?

What is thickest oil I can run ?

Thanks.

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GTRPSI Mentor

GTRPSI

Posted
Posted

Try 50 weight, should fix it if running a 30 weight currently, the thickness you run depends on the clearances used, if its worn run a thicker oil, our clearances are set up for a 60 weight of oil.

Sure your bypass is not stuck open? Have not heard of spring washers being used before, flat ones yes.

Thicker oil will bring the pressure up and open the bypass earlier.

The Mafia Grand Master

The Mafia

Posted
Posted

Factory RB30 pump is no good for a RB25 / RB30 hybrid. (Too small)

If you have pretty much zero oil pressure at idle is no good either - you may have done damage already.

I used a GTR spring in a RB25 pump.

Also, the sump needs to come off when you want to change the pressure. I actually cut a hole in my sump and welded a large bung in so I could change it from under the car. Just have to drop the oil.

Ben C34 Grand Master

Ben C34

Posted
Posted

Factory RB30 pump is no good for a RB25 / RB30 hybrid. (Too small)

If you have pretty much zero oil pressure at idle is no good either - you may have done damage already.

I used a GTR spring in a RB25 pump.

Also, the sump needs to come off when you want to change the pressure. I actually cut a hole in my sump and welded a large bung in so I could change it from under the car. Just have to drop the oil.

I considered the bung option also. I think if you weld a tube above the bung to the pressure relied valve it would mean you don't have to drop the oil.
iruvyouskyrine Grand Master

iruvyouskyrine

Posted
Posted

This is relevant to my interests.

Put my 25/30 together with standard RB30E oil pump. Shimmed it with 2 washers (approx 3mm) and had about 70psi at idle when cold. Running Penrite HPR 15w-40 racing full syn.

Was happy so took the gauge off. Got it tuned and drove it for 3 months. I have done a lot of K's and abused the shit out of the thing since (drifting so a lot of limiter bashing and clutch kicking, and also driven hard on street) and all seemed well and good. No noises or anything to indicate anything was wrong.

Then i did a two day drift event at wakefield park. I decided I would put the oil pressure gauge back in because I had it lying around. Early the first day after 2-3 laps I saw that at idle oil pressure would drop to 3-5psi at hot idle. That had me a little scared. I did a cool down lap slowly bringing the revs up and at around 6000rpm was getting about 50psi pressure.

So I went and dropped the oil and put brand new Penrite 15w-50 in hoping the heavier oil would give me an indication if it was just the gauge being dicky or if I had a genuine problem.

Still the same, had 60-70psi cold idle and then sat at 20ish or so when warm. After 2-3 laps it was back down to between 2-4psi hot idle and only had about 60psi at full noise (7000rpm).

There was absolutely no know gong noise or anything sounding like it wasn't getting properly oiled. Took fill cap off and there seemed to be plenty of oil in the head. Decided f**k it and kept drifting the remainder of that day and then did a full 5 hours of limiter bashing and extended periods of high revs on Sunday.

Is it possible to give it so much abuse and have it be fine with so little oil pressure? When I get a chance I will put a mechanical gauge on it to be sure but the 50 weight oils did seem to give it a few more psi at full noise.

Had multiple people look at it and listen to the engine listening for knocking or ticking or anything but it was fine.

I was pretty sure if I did have an oil pressure problem I would have killed it seeing as It had about 7 hours of abuse on track.

Any advice?

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