Oil Control In Rb's For Circuit Drag Or Drift

[Turbine]

Thanks for pic DiRTgarage, it's a nice way to do that mod with the fitting removeable.

Turbine.

[Guilt-Toy]

its allways good to have a catch can. its a must have IMHO

  blk180 said:

Also looks like twin fuel rails mmmm must be a nice car.

Noob question with the return form the back of the head would you still need a catch can.

Brad

[Craved]

Catch can is a bit general term to use..

catch cans are there for engine failures type issues so the oil is caught in that rather than sprayed all over the road/track .. this is a must have in every form of racing i've been involved with.

oil air separators that can do the above job aswell are for removing the oil vapour from the air leaving the head. and not re-introducing it into the combustion process.

[Scooby]

I'm looking into options for building a baffled/winged sump on an R32 GTR. In determining dimensions, is it simply a matter of figuring out how wide and deep you can make the wings and then plumbing the pickup accordingly? Does anyone have dimensions or pics of their set up that we could see?

Cheers

[Kamin]

Ok im reviving this one for a question

what about using an Accusump type of system to help aleviate the starvation problem? ( www.accusump.com )

but then what about too much oil in the head? my engine is assembled and i dont want to disassemble it to drill out the return or to ADD a return.

[tyndago]

Oil supply.... oil drain...

In our N1 car , it has an interesting swinging oil pickup. Cool Nismo piece. Seems to work well. Has a stock sump, stock baffleing - kinda and a swinging oil pickup. I posted some photos of it on gtr.co.uk.

Now if the oil level is in the normal range, the oil pressure will flucuate enough to get me a little afraid of it. I run it at the high mark, and under hard braking it goes down, but not enough for me to worry about any more.

We see about 1.6 g's peak cornering. R34 N1 on 305 Toyo RA1's all around.

The N1 motor doesnt even use an N1 oil pump, they run a Nismo pump. Interesting little thing.

The Tomei oil restrictor is smaller than the N1 restrictor. Stock being 2.0 mm , N1 being 1.5 mm , and Tomei is 1.2 mm.

In the N1 motor , they moved the cam baffle plates to the rear most cam caps. There is also a unique baffle plate in the valve cover.

For catch cans, there are two. A small one that collects and returns to the sump, and a larger one that is about what you see on most street cars.

I have run an Accusump in a GT-R. I never got around to some before and after datalogs of oil pressure though. The car didn't blow up out on the track, so I will assume it works out ok.

Edited August 3, 2006 by tyndago

[Sydneykid]

  Kamin said:

Ok im reviving this one for a question

what about using an Accusump type of system to help aleviate the starvation problem? ( www.accusump.com )

but then what about too much oil in the head? my engine is assembled and i dont want to disassemble it to drill out the return or to ADD a return.

Bad luck/timing, disassemble it and do it properly.

cheers

[carl h]

i was looking into the idea of the swinging pickup but that idea was shot to complete hell but i would like to know more about your setup and how long/how well it has worked out for you.

i run a rb20det rwd so the rear end will step out before i pull some obcene g's in the car, well least my car.

  tyndago said:

Oil supply.... oil drain...

In our N1 car , it has an interesting swinging oil pickup. Cool Nismo piece. Seems to work well. Has a stock sump, stock baffleing - kinda and a swinging oil pickup. I posted some photos of it on gtr.co.uk.

[haw001]

  Kamin said:

Ok im reviving this one for a question

what about using an Accusump type of system to help aleviate the starvation problem? ( www.accusump.com )

but then what about too much oil in the head? my engine is assembled and i dont want to disassemble it to drill out the return or to ADD a return.

The oil return is an easy thing to do even if the motor is assembled, provided it is out of the car. Pop the welsh plug out, drill and tap a new one with a 1/4 BSP thread and put a 90 elbow fitting in. If you drill closer to the edge of the welsh plug and install it near the top, you won't foul the metal lines that cross the back of the head.

The other side is to the sump, same scenario, but use a straight fitting.

[Duncan]

stuff oil control, I want to know how you pulled 1.6g in a full weight gtr on road tyres?

[tyndago]

  Duncan said:

stuff oil control, I want to know how you pulled 1.6g in a full weight gtr on road tyres?

Who said it was full weight ? 1.6 G's while cornering, on a circuit, honestly isn't that impressive. OK for a street race car, not good for a race car. R34 Racecar

The swinging oil pickup is made by Nismo. Its fitted to the Super Taikyu spec motors. Seems to work out alright.

[nemini90]

Hey guys just a quick Q for sk When you say drill out the oil returns what size can i drill them to in the head and block

Thanks heaps for all the info you guys have put up it has made my 25/30 project so much easier

[Scooby]

  haw001 said:

The oil return is an easy thing to do even if the motor is assembled, provided it is out of the car. Pop the welsh plug out, drill and tap a new one with a 1/4 BSP thread and put a 90 elbow fitting in. If you drill closer to the edge of the welsh plug and install it near the top, you won't foul the metal lines that cross the back of the head.

The other side is to the sump, same scenario, but use a straight fitting.

1/4 BSP is a bit small for a gravity oil return, about 12mm ID seems to be common

[rob82]

Has anybody tryed venting the sump to atmoshpere/catch can to prevent the pressure build up within the crank.

My thoughts are that with sustained high rpm/load the crankcase is pressurising causing the oil not to drain back to the sump. The oil galleries are below the level of oil which means if the sump is pressurised there is no way for oil to drain back. This is why the mod to drain the back of the head via the welch plug on the rear will work as is it more to do with equalling the pressure differential between head and sump than being a drain - but what happens if the oil level is above the level of the rear drain you going to get the same situation.

The way I see it is if the sump itself is vented then you will never have any issue as all the oil drains back from the head will be more than ample to keep the oil in the sump.

It might be an easier option then lifting the head as well if your enigne is back together.

[The Mafia]

why isn't this thread a sticky?

[Sydneykid]

  rob82 said:

Has anybody tryed venting the sump to atmoshpere/catch can to prevent the pressure build up within the crank.

My thoughts are that with sustained high rpm/load the crankcase is pressurising causing the oil not to drain back to the sump. The oil galleries are below the level of oil which means if the sump is pressurised there is no way for oil to drain back. This is why the mod to drain the back of the head via the welch plug on the rear will work as is it more to do with equalling the pressure differential between head and sump than being a drain - but what happens if the oil level is above the level of the rear drain you going to get the same situation.

The way I see it is if the sump itself is vented then you will never have any issue as all the oil drains back from the head will be more than ample to keep the oil in the sump.

It might be an easier option then lifting the head as well if your enigne is back together.

That's a good solution if blow by is a problem. But that's got zero to do with the fact that the head has insufficient oil return capacity for sustained high rpm. Venting the sump does nothing for that problem.

The oil return is best done to the LHS of the sump. Since the crank turns clockwise, that means the oil is returning into the partial vacuum created by the crank rotation. Hence the oil flows intro the sump. Oil level nothwithstanding.

cheers

[Shockster0429]

  The Mafia said:

why isn't this thread a sticky?

+1 Ive got this damn thread even bookmarked under favorites. Awesome info from SydneyKid

[fatz]

my solution to oil dramas in a rb30det (gtr head) and stock bottome end is average oil (magnatec)

anything lighter and it blows by

magnatec is the shit for stock bottome ends

yea baby!!!!

just filler her up and extra two litres for circuit work!!!

cheap effective (buit overall stupid)

[AndrewD]

has anyone who has done this modification of restricting oil flow and lowering oil pressure to the cam journal bearings noticed increased wear?

the problem seems like its an oil return, not a supply problem. if you restrict the flowrate the cylinder head doesnt recieve enough cooling. also the pressure drops because of the restriction and you now have issues with maintaining the hydrodynamic lubrication of the journal bearings. this leads to increased mechanical contact between the bearing surfaces.

why not do as is already suggested and improve return oil flow? increasing oil gallery size and added external lines are perfectly fine.

[GTRgeoff]

Sk would have noted that already on the RB powered race cars he deals with, so clearly not a problem. I'm about to pull down my 25 that I had blocked the front supply off on so will know soon enough.

Clearly this is not just a return problem but a oversupply problem at high RPM as well, hence the restrictions.