Hhigh Oil Pressure With Jun Pump Then Drops At High Revs?

[wsln33]

Hey guys,

I just got my car back from a 3 year build. Its a 26/30. It has a jun pump.

All is going well with it but the tuner says the oil pressure is high at around 130-140 psi but then drops to 120ish over 6500rpm. He was concerned about this? Do jun pumps usually run this high? and is the dropping oil pressure a concern or is it still plenty of oil pressure to keep everything happy?

[The Dan]

You'll have problems with that much oil pressure.

110 is probably the maximum you would want to see. 90-100 is more normal.

What bearing clearances were used and was the pressure relief valve checked before the pump went on?

[wsln33]

You'll have problems with that much oil pressure.

110 is probably the maximum you would want to see. 90-100 is more normal.

What bearing clearances were used and was the pressure relief valve checked before the pump went on?

Dont know the bearing clearances right now. I wouldnt think the pressure relief valve was checked. The pump was just put on. How should the relief valve be checked?

What sort of problems will I have with that much oil pressure? Im running the engine in at the moment and have to put 1000km on it so will it be ok before I have to take it back?

Thanks mate

[Swiper the Fox]

the crack off pressure of a JUN pump is 120psi

should have used a STD RB30 oil pump...they rarely break or give problems.

Edited April 28, 2009 by DiRTgarage

[Guilt-Toy]

the crack off pressure of a JUN pump is 120psi

should have used a STD RB30 oil pump...they rarely break or give problems.

ohhh snap

[wsln33]

the crack off pressure of a JUN pump is 120psi

should have used a STD RB30 oil pump...they rarely break or give problems.

Sorry mate, whats the crack off pressure?

[unique1]

the crack off pressure of a JUN pump is 120psi

should have used a STD RB30 oil pump...they rarely break or give problems.

dont the 30 pumps run the small oil pump drive though? im talking on the oil pump not the crank.

[r33_racer]

yeh! I think its only like 9/10mm wide from memory?!?!

[shanef]

sump needs to come off to fix the oil pressure issue. pita but its gotta be done

[Swiper the Fox]

dont the 30 pumps run the small oil pump drive though? im talking on the oil pump not the crank.

thats correct...the pump is a different gear design and is not prone to the Jap pump problems. Pull one apart and you will see what i mean.

crack off pressure is the point at which the relief valve opens.

Edited April 29, 2009 by DiRTgarage

[shanef]

thats correct...the pump is a different gear design and is not prone to the Jap pump problems. Pull one apart and you will see what i mean.

crack off pressure is the point at which the relief valve opens.

thats right they are like the tomei pumps, they run a 'spline' drive gear setup

i wouldnt trust one on a big dollar motor though

[Swiper the Fox]

thats right they are like the tomei pumps, they run a 'spline' drive gear setup

i wouldnt trust one on a big dollar motor though

But your not Maatouk's, Birrong Automotive, JW Auto etc running 8's with them

Dan what problems will around 135psi at low RPM produce?

Edited April 30, 2009 by DiRTgarage

[FineLine]

What oil pump do you run Dirtshirt man?

[Swiper the Fox]

What oil pump do you run Dirtshirt man?

RB20

[FineLine]

RB20

Thats probably why you only run 9's. If you ran the 30 pump like all those other fancy stables you might crack 8's.

[Swiper the Fox]

Thats probably why you only run 9's. If you ran the 30 pump like all those other fancy stables you might crack 8's.

lol...im struggling to even run a 9 now, we will see what happens when the car arrives up here to race. A few little tricks we have planned for it.

Also you can add JPC and most of the Melbourne VL boys to that list.

Im currently running a JUN pump now but will go to a Peterson external pump when it breaks.

My forklift bottom end will run a VL series II or VL turbo pump (they are the same) reco'd and modified by JW Auto.

Edited April 30, 2009 by DiRTgarage

[FineLine]

lol...im struggling to even run a 9 now, we will see what happens when the car arrives up here to race. A few little tricks we have planned for it.

Also you can add JPC and most of the Melbourne VL boys to that list.

Im currently running a JUN pump now but will go to a Peterson external pump when it breaks.

My forklift bottom end will run a VL series II or VL turbo pump (they are the same) reco'd and modified by JW Auto.

A little birdie told me the car is only 2 minutes from my pad as I type.

Might go round and key it tomorrow.

[Swiper the Fox]

A little birdie told me the car is only 2 minutes from my pad as I type.

Might go round and key it tomorrow.

your 'little birdy' has been snorting too much powdered cuttlefish.

i know where the car is and its no-where near you Fox.

Edited April 30, 2009 by DiRTgarage

[FineLine]

your 'little birdy' has been snorting too much powdered cuttlefish.

i know where the car is and its no-where near you Fox.

We'll see.

[The Dan]

Go Broncos!!