Oil Control In Rb's For Circuit Drag Or Drift

[JimmyRickard]

I've been quoted for a day's labour for it to be done with the engine in. Is this realistic? Also is there more room for error when the engine hasn't been removed, therefore creating problems?

[sly32]

I'd say pump is bigger?

More flow and pressure than stock....at the same rpm.

damn that could be bad then as i want to use this car for drift, i dont want to much oil getting to the head, mmmm or maybe it will just read at 4 on first start up cause the oil is cold, i havent driven the car yet or let the oil warm up so most likely it will drop in oil pressure with the oil been warm? any thoughts about this?

cheers jv

[Jase]

Hey guys, is it possible to install a Sump Baffle Kit without pulling out the engine? I've rang about 5 workshops, and out of those 5 only one was willing to do it without pulling out the engine, so I wonder whether it can be done at all or if it can be done but it will be a shit job.

yes it can be done

Boostworx in SA do it that way

I'm not sure of the exact details of how its done but its easy to do apparently

Cubes might know

[GTRsean]

damn that could be bad then as i want to use this car for drift, i dont want to much oil getting to the head, mmmm or maybe it will just read at 4 on first start up cause the oil is cold, i havent driven the car yet or let the oil warm up so most likely it will drop in oil pressure with the oil been warm? any thoughts about this?

cheers jv

When oil is at 80 degrees temp it should be at around (roughly) 20 psi

When it's cold oil pressure will be a lot higher.

[AllenSaldi]

What size is recommended for the return line coming from the back of the head to the sump. I was thinking about having a plug pressed into the back of the head that extends slightly outwards towards the rear of the car like other have done before instead of having to put a 90 Degree elbow back there. I was just curious what size (AN) the fitting and line should be.

[Duncan]

its possible but not easy to do in the car. I was most worried about properly cleaning and resealing the sump with goop. so I took it out instead.

if enough of that stuff gets stuck in your oil pickup, bye bye motor

[inmate]

Is an RB25DE oil pump the same as an RB25DET one?

[Guilt-Toy]

i did the rb30det oil pump with engine in the car, did not take the sump completly out. used heaps of goo and its not leaking so all is good

its possible but not easy to do in the car. I was most worried about properly cleaning and resealing the sump with goop. so I took it out instead.

if enough of that stuff gets stuck in your oil pickup, bye bye motor

[700HP-GTR33]

Hello,

These are recommended to do for drag/circuit or drift cars with after market oil pumps

QOUTE

1.Block off one oil feed in the block (RB26’s have this standard)

2.Fit an appropriately sized restrictor to the other feed. The size of the oil pump is one of the determinates for the size of the restrictor, ie; a high flow, high pressure pump needs a smaller restrictor. Constant higher RPM needs a smaller restrictor etc.

3. Fit an external oil return from the rear of the cylinder head to the sump

4. Drill out the oil return galleries in the head and block

5. Machine around the oil return galleries to facilitate access for the oil

QUOTE

I am running a N1 pump.

Can anyone give me the right sizes I will need to drill out.

1-the sump(5) 2mm holes to?

2-the return oil supply to the sump(Block and Head) to?

A 1.5mm Tomie restrictor and Sump baffle will be used and No external oil return.

The car will mostly be run on the street with little or no drag/circuit use.

Thanks in advance?

[Angus Smart]

also like to know the above may aswell do this while the engine is in pieces right!!

[tufrx3]

I hope this helps with the external drain..

This is a fitting that i made for the oil return... As for oil restrictor i am not 100% sure but people run a 1.5mm tomei one or a brass one like i have made..

Hope this helps

regarding restrictors and such, what kind of restrictors should one use on a rb20 using a n1 oil pump?

also ive a shot the back of my head and not sure where i should fit the external drain, advice on both q's is always appreciated.

[Kevin Johnson]

Makes no difference, the pressure relief valve controls the oil pressure.

cheers

A restrictor valve to the head can lower the pressure in that portion of the circuit.

[Kevin Johnson]

Sorry to bring this back from the dead.

I plan on doing Tomei sump mod, and probably the line from rear of head to sump.

I talked to my machnist and he says the restrictor seems like a reasonable idea to limit flow for oil surge issue. The problem he says for my application is he's worried about the hydraulic lifters with the oil gallery restrictor. He described a VERY similar problem that can happen to the individual on this forum who ended up having lifter noise.

My application is for street driving and occasional/frequent drag racing and less occasional road racing.

The restrictor gives lower oil pressure in the galleys for the lifters. This lower pressure allows entrained air in the oil supply to coalesce and interfere with lifter operations. Under higher pressure in the circuit prior to the restrictor the bubbles are smaller. This decrease in size is one of the reasons high pressure is used in oil circuits.

If you are running mechanical versus hydraulic lifters restricting the oil supply to the head is less problematic with respect to entrained air.

[Kevin Johnson]

I am trying to do as much research as possible on the RB motors, and being from the USA makes it a lil difficult as the motor is rare, and most information is in Japanese. I have an RB20DET, and the last thing I want is oil starvation, as the parts to repair it are expensive and hard to come by. I do have a few questions regarding this topic.

-It seems this is an issue with all RB motors, is this true?

-Will restricting the oil to the head cause any problems?

-Has anyone considered having their crankshaft, connecting rods, and the underside of their pistons coated with an oil shedding material such as teflon?

If this is an issue with all RB series motors why didnt Nissan address the issue by restricting oil to the head from the factory? Did they determine that reducing oil to the head would cause more harm? An oil shedding material coating the internals of the engine would allow the pan to fill faster, and create more horsepower as the RPMs climbed.

One of the restrictions on the efforts of the Nissan engineers was/is the "corporate" hump in the rear of the oil pan. This hump is present to allow easier access to torque converter bolts (I was told this and assume it is correct). The hump creates a large problem because under high G conditions the oil naturally migrates to the rear of the pan. The volume that the hump displaces and its ramping effect create a churning zone for oil where the oil becomes highly aerated -- this is also the principal drain zone for the heads. Get rid of the hump. If you carefully examine the engineering on the SR20 you can see the problems the designers had with the local high pressure zone created in the 4th bay by the hump.

Increasing the amount of oil in the pan is problematic because at the G-limit of the design the excess oil naturally migrates to this same zone. This situation parallels the failure mode for the Toyota 2ZZ engine in the Spyder and Elise, both of which can exceed the 1G design limit of the stock pan. The high aeration of the oil causes the failure of the Geroter pump. If the pump can withstand the aeration then the problem would shift to the first rods to receive the mixture. In the Porsche 928 and 944 engines this lead to the classic 2/6 rod failures. Looking at the Tomei drawing of the oil circuit it looks like rods three and four would be hit. Failures of the number 6 cylinder would likely be due to localized overloading of the ring pack and detonation or incipient detonation. Because of the hump there is no windage control in the last bay. A good solution to this would be a dual pump as in the BMW M3 (S50 engine) where the secondary pump could scavange from this zone and transport the oil back to the sump well. This is passing into the transition from wetsumps to drysumps. The Porsche integrated drysump takes this a step further (a type of active wetsump).

I only have an RB26DETT pan (with AWD) to look at. In this pan, the witness marks from the oil indicate that it normally operates with 2 quarts or liters resident in the sump proper, the balance being in circulation. This is a fairly typical amount.

[Duncan]

"I only have an RB26DETT pan (with AWD) to look at. In this pan, the witness marks from the oil indicate that it normally operates with 2 quarts or liters resident in the sump proper, the balance being in circulation. This is a fairly typical amount."

absolutely agreed....in road car use. as soon as you keep the revs up for a while they run dangerously low on available oil for the pick up.

you obviously have extensive experience with oil issues - how would you modify the sump for more reliable oil pick up??

[tufrx3]

"I only have an RB26DETT pan (with AWD) to look at. In this pan, the witness marks from the oil indicate that it normally operates with 2 quarts or liters resident in the sump proper, the balance being in circulation. This is a fairly typical amount."

absolutely agreed....in road car use. as soon as you keep the revs up for a while they run dangerously low on available oil for the pick up.

you obviously have extensive experience with oil issues - how would you modify the sump for more reliable oil pick up??

I heard of people putting trap door systems into their sump..Its like a little box with flaps to let oil into the box and keep it there (i think that this is the principle behind it). This is an option.

[WARLORD]

is this a good fitting to use.

[johnbarry88]

that looks like a good idea for space, but it would make it hard to change if the motor is in the car? not much room to swing a spanner..

[WARLORD]

i found this today but im not sure what the note means this is what it said,(combine with std Orifice use For RB25&20, ONLY solid type is available (cannot used on lash type) can some one translate.

[handyandy28]

hey hope you guys can help a gimp out

I a building an rb30det for street use and have a few questions. I am running the rb25de head (non vvt) and am wondering which feed i restrict and which i block off, i understand there are only 2?

do i block off the one closest to flywheel or closest to cam gears? Does any one have a photo or drawing of the job (birds eye view or something)?

Hope you can help a nub out

Cheers