Oil Control In Rb's For Circuit Drag Or Drift

[gtr jet]

I've got a fitting on the exhaust side of my sump in the middle of the wing which I take it is bellow the oil line.

Does anyone have an idea of what would happen if I connected this to my valve cover breather or catch can?

[djr81]

Valve cover not much. Catch can I wouldn't. You don't want to put oil between the blowby and its escape to atmosphere. Essentially this is what goes on in the head and you don't want to replicate it in the sump extension.

Above the oil line yes, below no.

Edited August 13, 2015 by djr81

[gtr jet]

So if I did connect it to the valve cover it would probably just try to blow oil up the line?

[djr81]

Nah because there shouldn't be much difference in pressure between the sump and valve cover. Certainly not as much as between the sump and the catch can. I would expect it to pump oil into the catch can every now and then which is why I wouldn't do it that way.

[gtr jet]

Obviously there is something wrong with my set up as my catch can is always pressurised.

On the street it's not too bad and on the track below 7000rpm there is only a bit of oil but whenever I take it past 7000rpm I teld to get a lot of E85/oil in the can.

The can is vented to atmosphere with one fitting to each cam cover.

[djr81]

High revs seems to be where the problem is worst for most people.

[KiwiRS4T]

I've got a fitting on the exhaust side of my sump in the middle of the wing which I take it is bellow the oil line.

Does anyone have an idea of what would happen if I connected this to my valve cover breather or catch can?

Nothing good. Don't even think about it.

[KiwiRS4T]

Obviously there is something wrong with my set up as my catch can is always pressurised.

On the street it's not too bad and on the track below 7000rpm there is only a bit of oil but whenever I take it past 7000rpm I teld to get a lot of E85/oil in the can.

The can is vented to atmosphere with one fitting to each cam cover.

Read about the last 10 -15 pages of this thread and all will be revealed if you choose to see.

[gtr jet]

I've been reading since page one and I know how to fix the issue. I just don't want to pull the motor back out to tap the sump again.

[Kao13]

Yeah sorry, I did read the entire 70 pages, I still call it a head drain as they are still marketed as a head drain, I understand the the whole concept it's just I was thinking if my particular setup with the rear head BREATHER would be worth keeping or just blanking off. The only reason I didn't run it through the catch can first was because I ran out of ports. What are the opinions of the turbo return to sump below my front head breather/drain?

[GTSBoy]

I said ditto front.

[SSM]

Ok, guys. I have talked to a guy here in Norway that have run his 700hp RB26 for 30.000km without issues. He does a lot of trackdays as well. I have seen his car and figured that I should ask him how and what he has done to the oil system. He has done as follow:

-Drilled the return galleries

-Rear head drain to under oil level AN10

-Rocker cover breathers to top of catch can AN12

-Rear twin turbo return line works as a crankcase vent to top of catch can

-Catch can return line to sump under oil level

-And a modified Trust/Greddy oilpan sump

What oilpump and restrictor he is using I do not know. I'm using JUN pump and 1.2mm

So, I went to use his solution. But I'm swaping into another chassis, so to build the sump downwards is not an option. Here are some pictures of how far I have come now. And I'm happy to get input on this. Remember, this is my first RB26 so do NOT copy this and think this is a top of the line solution.

I delivered my engine to the best engine builder in Norway. He has build some 25-30 RB engine over the years. Most of the engines that comes out of his shop runs and runs and runs. I think it is probably because he is very detail orientated and checks everything twice.

What I wanted he to do is a lot, but now lest focus on the oil control. I told him to drill out the return galleries. And since I have not found any damn pictures of that being done in this thread I might as well post it. This is done by a professional, and it is not recommended doing on the garage floor with a hand held drill.

Fist he cleaned the block, pressure tested it and honed it:

The oil is returning in these small holes as seen here

Here as seen with the Cometic MLS head gasket laid on

No fancy equipment, just e regular drill

The drill is marked to how deep he was going to drill the hole

Here you can see the other side of it

Then he decked the block to the finish an MLS gasket requires as well as degrading

The same was done to the head

And the result with the head gasket back on

The block got powder coated and is ready for further assembly

[GTRPSI]

How many mm did you drill out your block oil returns to?

No pics you say, plenty of pics.....ive got these pics in a few threads for RB30's.

I even did my own annular groves in the RB30 block to get oiling under the bearing seats like on RB26's.

Edited August 13, 2015 by GTRPSI

[Looney_Head]

Hi people,

i have a question regarding catch can setups, i have put two -12 fittings on the drivers side of sump as high as possible with the intention of running one to the top of the catch can and the other to the bottom of the "strained" side of the can for a drain.

my question, is it safe to run this setup when using E85, i have read that E85 will do nasty things to oil and the vapour out of the breathers has a heavier water content than regular gas.

also nice pics GTRPSI and SSM

cheers.

Phillip

Edited August 18, 2015 by Looney_Head

[The Mafia]

I just got my oil test back after running about 300L of E85 through my RB26 with 400awkw. (Stock motor with 50,000kms on it).

Tests had less water in the oil than when I was just running 98.

[Looney_Head]

I just got my oil test back after running about 300L of E85 through my RB26 with 400awkw. (Stock motor with 50,000kms on it).

Tests had less water in the oil than when I was just running 98.

wow awesome, thanks for that reply. guess i will be going with the two line option.

[ScreamerNewbie]

Well this is the kinda stuff ya catch can catches on a fresh engine after 1 weekend at racewars (1000m drag racing) with e85, my setup was -12 from each baffled cam cover to cams approved catch can, 2x -12 sump breathers from Intake side of sump above oil to catch can. All inputs to catch can are at the same height, no drain back. Catch can is very well baffled and vented

Ill let u decided if you wish to drain the cc back to the sump

[Looney_Head]

Thanks Screamer. That doesn't look like something I want going into oil. Have you had any analysis done on that to see what it’s made up of? What run in did you do on the fresh engine out of curiosity?

[GTSBoy]

That's emulsified oil and water. Exactly what you'd expect. Realistically, if you are running a non-draining catch can on a competition car, then you'd be fine with having to empty it out yourself. But for a street car, where ideally the crankcase gases are passed from the catch can to the intake, and you'd probably not want to be manually emptying your can, then draining it back would increase the water content of the oil, which would boil off in the sump, which would come to the catch can as vapour and be sucked into the intake and disposed of. Some of the moisture would condense in the lines and can and pass back to the sump, exactly as it does in any other engine. So it's not a huge problem to let the milk stay in the system.

[ScreamerNewbie]

Yeah dusnt look good. In saying that this looks very similar to the oil that comes out of the drag car i crew on (top alcohol funny car) and we run it again and again for around 5 passes. Though we also change bearings more than our undies so again ill let u be the judge.

I havent had it tested, as i said it dusnt look the best and with auch a large sump (9L oil total) i decided no need for me to return it anyway.

I did 1000kms run in.