Rb26 Oil Restrictor Question

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hey guys .had problems with oil pressure due to bearing clearance change the bearings and now its a lil better.

now at start up i usually get around 76psi cold start blip the throttle would get as high as 90+ psi , idle is around 30psi warm hot it 22 psi.

now i have no oil mods ,no tomi oil restrictor or head drain bk. the oil pressure shots like this

1000 rpm>>22 psi

2500 rpm>>45psi

3500 rpm>>60psi

4500 rpm>>70psi

5500 rpm>>75psi

and stays 75 psi to redline (stock)

i notice everyone here has relatively high psi 90+ psi up top , but i notice they also have tomi oil restrictors does that really make such a difference in oil pressure?

even the service manual i think recommends u should see around 66psi by 6000rpm

am running a n1 pump with replacement billet gears and a custom 8 liter sup with baffles...

is it the nature of the pump to free flow at higher rpm ?

[GTRPSI]

Golden rule is you need 10psi for every 1000 rpm.

Oil restrictor size does little for oil pressure down in the bottom end.

What weight of oil are you running?

What clearances are you running on the bearings?

Are you running a aftermarket pressure gauge?

[89CAL]

Did you check the relief pressure on the N1 pump? Might need to be raised. I think mine is borderline but just enough pressure up top

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am running 20w-50 as am living in the tropics & clearance is about 2 thou.. also running a small oil cooler... am only revving stock 7800rpm so am not in any real danger but i would have been more comfortable with a lil extra space psi to the top.

[iruvyouskyrine]

Golden rule is you need 10psi for every 1000 rpm.

Is this at standard operating temperature?

[Ben C34]

Is this at standard operating temperature?

Yes.

You wouldn't rev to 8000rpm when cold.....

[GTRPSI]

If its 50 weight and only going to 75 with 20 thou it sounds a bit low.

Did you check the clearances yourself or did you take for granted what the machinist said?

In my case i gave my target clearances to the machinist, got the block home and double checked it myself while mocking up everything a few times and found he was miles out on the rods but spot on the crank mains. (i found out the machinists apprentice set them up after i went back to show them or so he claims)

Otherwise sounds like oil pump shim time, which is why i used a Tomie pump, nothing beats being able to remove a cover nut and adjusting the pressure as needed.

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yea could be shim time..but i have seriously long gears so even bringing down the rev to 7500 rpm i still clock 120mph in 3rd ..that trip to take down that oil pan is a bitc* ...rather lower the rev and use boost to get the hp....

oil pressure isn't all of it once i have a good flow..