Jump to content
SAU Community

Recommended Posts

120psi is fine. That is a rough guide of what it will be. But as said that can change depending on main, rod and rod side clearances used in conjunction with what viscosity oil is run. You might find hot you will only achieve 100psi. Stop worrying about the oil pressure and have the oil squirters put back in.

Your engine builder should know that system pressure is controlled via bypass and by grub screwing the oil squirters he is only reducing a fraction of the pumps potential supply volume, not pressure. Your bypass may open sooner without the squirters now, assuming everything else being the same.

Forget the head oil problem by running high pressure, if you have small 1.0mm-1.2mm restrictors and head drains opened up and adequate crankcase ventilation to a breather can you will be fine in that regard.

  • Replies 58
  • Created
  • Last Reply

Top Posters In This Topic

So the guys using non A8 blocks for there rb30/25 would be running no oil squirters? What's the difference between non in a rb30 and none in a rb25???

Assuming some use the non A8 block not to sure what block they use for the 30/25 build

The vl turbo block doesn't have squirters either

Really? I was always under the impression they did.

Running oil squirters is a big advantage to not using them.

They help to cool the pistons and lubricate the bores. Pulling them out is a step back wards.

Yes correct, people who turbo RB30E's do not have oil squirters but if they did the user or engine builder wouldnt go removing them.

Being a parrallel thread I'd like to see how he securely grub screwed the gallery without just banging a grub in there and blocking off the gallery internally. It can be done obviously but wonder if he went to the effort. I think the thread goes well into the gallery from memory.

I vaguely remember those squirters coming off the main internal gallery that feeds the crank??

Be interesting if his put grub screws in the squirter holes and restricted the main artery with them.....

You'll have great oil pressure then... Not much to the bearings though.

Being a parrallel thread I'd like to see how he securely grub screwed the gallery without just banging a grub in there and blocking off the gallery internally. It can be done obviously but wonder if he went to the effort. I think the thread goes well into the gallery from memory.

I vaguely remember those squirters coming off the main internal gallery that feeds the crank??

Be interesting if his put grub screws in the squirter holes and restricted the main artery with them.....

You'll have great oil pressure then... Not much to the bearings though.

I can't comment on how he went about the grub screw but when I showed up with my nitto pump and it been 120psi he did mention about putting the squirters back in, but then he ended up playing with the springs to set the psi

So if rb30 blocks don't have oil squirters what is the diffence between a rb30 without squirters to a rb25 with squirters, yes I know rb25 came out with the squirters so lodgic says it should stay there but in this case it's not, just trying to see the points on why the rb25 has the squirters to cool pistons down and to lube the bore, but a rb30 doesn't, so wouldn't a rb30 have problems?

Rb30 is an older tech motor. So the newer version ie: rb25, nissan engineers decided to use oil squirters to keep piston temps in check.

People want the extra torque from rb30's which is fine but they must be built accordingly. So larger tolerances to allow for extra alloy piston expansion etc. or coating the piston tops

*sigh*

Pressure is restrciction to flow.

Think about a garden hose with no end on it, water runs out. Put your finger over the end (i.e make a restriction) and the water shoots out at a higher pressure

More pressure often equals less flow, but its not that simple as in they are not directly proportional (from memory). But at no flow you would hit the pumps relief setting so you would get maximum pressure at minimum/no flow

And the flow is determine by how much pressure? More pressure more flow?

yes and no. Different pump designs, oil viscosity, temp etc will dictate the flow rate at a given pressure...essentially it's the same principle as aftermarket turbo's, the airflow @6psi on a stock turbo can be totally different to the airflow @6psi on an aftermarket turbo

And just to add to the rest of the conversation, does an n1/oem oil pump operate at ~120psi (8bar) at redline?

Edited by wedge_r34gtr

Different pump designs - positive diplacement and centrifugal need to be thought of differently.

Unlike a centrifugal pump a positive displacement pump's speed is the sole arbiter of its output. It will pump a certain amount of fluid (oil in our case) per revolution almost irrespective of the pressure it is pumping against. However, different pumps give you different amounts of oil because their gear designs are different. Obviously a smaller pump will move less oil per revolution by design.

What happens to the pumps output is dictated by the pressure relief arrangement and the engine design (bearings clearances, oil galleries etc). The oil can only go in one of two directions - out the relief or through the engine. The lower the relief spring constant and seat force (which are added, obviously) the more oil goes through the relief side of the pump and the less goes through the motor. By increasing the pressure relief on the pump you force more oil through the motor.

It is difficult to compare to turbos because the waste gate functions in an analagous manner to the pressure relief device on an oil pump save for the fact it is on the turbine not the compressor

yes and no. Different pump designs, oil viscosity, temp etc will dictate the flow rate at a given pressure...essentially it's the same principle as aftermarket turbo's, the airflow @6psi on a stock turbo can be totally different to the airflow @6psi on an aftermarket turbo

And just to add to the rest of the conversation, does an n1/oem oil pump operate at ~120psi (8bar) at redline?

not completely true. Its different to air.

Pressure IS pressure, it dont matter if your pump flows 8KL at redline if you have a certain size restriction, with same oil, and same pressure, the flow will be identical. The only time flow of pump counts is at idle when relief valve is shut. If both are set to certain pressure both will move the exact same at full revs.

Having one at 75 and one at 70 psi the higher pressure does mean more oil flow, through pressure, not pump capacity. If this makes sense

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Hey Dave, welcome aboard! Good to see another soon-to-be Stagea owner here. The wagons are awesome — plenty of space, still got that Skyline DNA, and loads of potential if you’re into mods. Definitely post up pics when you get it, everyone here loves seeing new builds. What model/year are you looking at?
    • See if you can thermal epoxy a heatsink or two onto it?
    • The other problem was one of those "oh shit we are going to die moments". Basically the high spec Q50s have a full electric steering rack, and the povo ones had a regular hydraulic rack with an electric pump.  So couple of laps into session 5 as I came into turn 2 (big run off now, happily), the dash turned into a christmas tree and the steering became super heavy and I went well off. I assumed it was a tyre failure so limped to the pits, but everything was OK. But....the master warning light was still on so I checked the DTCs and saw – C13E6 “Heat Protection”. Yes, that bloody steering rack computer sitting where the oil cooler should be has its own sensors and error logic, and decided I was using the steering wheel too much. I really appreciated the helpful information in the manual (my bold) POSSIBLE CAUSE • Continuing the overloading steering (Sports driving in the circuit etc,) “DATA MONITOR” >> “C/M TEMPERATURE”. The rise of steering force motor internal temperature caused the protection function to operate. This is not a system malfunction. INSPECTION END So, basically the electric motor in the steering rack got to 150c, and it decided to shut down without warning for my safety. Didn't feel safe. Short term I'll see if I can duct some air to that motor (the engine bay is sealed pretty tight). Long term, depending on how often this happens, I'll look into swapping the povo spec electric/hydraulic rack in. While the rack should be fine the power supply to the pump will be a pain and might be best to deal with it when I add a PDM.
    • And finally, 2 problems I really need to sort.  Firstly as Matt said the auto trans is not happy as it gets hot - I couldn't log the temps but the gauge showed 90o. On the first day I took it out back in Feb, because the coolant was getting hot I never got to any auto trans issues; but on this day by late session 3 and then really clearly in 4 and 5 as it got hotter it just would not shift up. You can hear the issue really clearly at 12:55 and 16:20 on the vid. So the good news is, literally this week Ecutek finally released tuning for the jatco 7 speed. I'll have a chat to Racebox and see what they can do electrically to keep it cooler and to get the gears, if anything. That will likely take some R&D and can only really happen on track as it never gets even warm with road use. I've also picked up some eye wateringly expensive Redline D6 ATF to try, it had the highest viscosity I could find at 100o so we will see if that helps (just waiting for some oil pan gaskets so I can change it properly). If neither of those work I need to remove the coolant/trans interwarmer and the radiator cooler and go to an external cooler....somewhere.....(goodbye washer reservoir?), and if that fails give up on this mad idea and wait for Nissan to release the manual 400R
    • So, what else.... Power. I don't know what it is making because I haven't done a post tune dyno run yet; I will when I get a chance. It was 240rwkw dead stock. Conclusion from the day....it does not need a single kw more until I sort some other stuff. It comes on so hard that I could hear the twin N1 turbos on the R32 crying, and I just can't use what it has around a tight track with the current setup. Brakes. They are perfect. Hit them hard all day and they never felt like having an issue; you can see in the video we were making ground on much lighter cars on better tyres under brakes. They are standard (red sport) calipers, standard size discs in DBA5000 2 piece, Winmax pads and Motul RBF600 fluid, all from Matty at Racebrakes Sydney. Keeping in mind the car is more powerful than my R32 and weighs 1780, he clearly knows his shit. Suspension. This is one of the first areas I need to change. It has electronically controlled dampers from factory, but everything is just way too soft for track work even on the hardest setting (it is nice when hustling on country roads though). In particular it rolls into oversteer mid corner and pitches too much under hard braking so it becomes unstable eg in the turn 1 kink I need to brake early, turn through the kink then brake again so I don't pirouette like an AE86. I need to get some decent shocks with matched springs and sway bars ASAP, even if it is just a v1 setup until I work out a proper race/rally setup later. Tyres. I am running Yoko A052 in 235/45/18 all round, because that was what I could get in approximately the right height on wheels I had in the shed (Rays/Nismo 18x8 off the old Leaf actually!). As track tyres they are pretty poor; I note GTSBoy recently posted a porker comparo video including them where they were about the same as AD09.....that is nothing like a top line track tyre. I'll start getting that sorted but realistically I should get proper sized wheels first (likely 9.5 +38 front and 11 +55 at the rear, so a custom order, and I can't rotate them like the R32), then work out what the best tyre option is. BTW on that, Targa Tas had gone to road tyres instead of semi slicks now so that is a whole other world of choices to sort. Diff. This is the other thing that urgently needs to be addressed. It left massive 1s out of the fish hook all day, even when I was trying not too (you can also hear it reving on the video, and see the RPM rising too fast compared to speed in the data). It has an open diff that Infiniti optimistically called a B-LSD for "Brake Limited Slip Diff". It does good straight line standing start 11s but it is woeful on the track. Nismo seem to make a 2 way for it.
×
×
  • Create New...