Oil Pressure, Head Restrictor, Big Pump = Too Much Oil

[BoostdR]

What valve do you have on order?

This one Valve

I may indeed not need it now. I may even bring my problem back... ARC do a catch can that returns to the dipstick that uses a check valve also..

[rockabilly]

right where to start.lol.

we have had alot of issues in the uk with the rb30,s on track whether it be an rb25 head or 26. on the road mine blows nothing, on spirited driving it blows nothing,zero, on track it throws it into the catch can. i run a tomei oil pump. back restrictor is blocked of fully, front one runs a .65 restrictor, yes you read that correctly. i run mines cam baffles and silkolene 15/50 pro oil. my cam cover pipes go to a catch can, from there the vent pipe goes down to another catch can near the sump. from that catch can the other pipe comes back up and vents to atmo behind the drivers headlight. the main catch can behind the drivers headlight also has a drain to sump on it..this has sorted all the track blowing oil out issues. i have done leak down, compression tests the lot. if you run an rb26/30 on track hard with over 1.6 bar boost or 650bhp it will blow oil out end of, what you have to do is control it and return it back to sump..its seems the 26 is suited for track and the 30 just isnt, we have a dozen or more here with the same problem including the original ripps uk001 engine. to4z powered. at castle comble the other year it blew a gallon of oil into the tank after 20 laps...?.this one was built by rob himself is very famous. was fitted to a white 33gtr that ran 10,s in nz. bernie uk

p.s if i build another i would put a .25 restrictor in the front and block the rear.i have just done a comprssion test on mine with the cam covers of,even without it running just turning over the cams are soaked with oil thats pumped up..

Edited September 20, 2010 by rockabilly

[R32 TT]

..its seems the 26 is suited for track and the 30 just isnt, we have a dozen or more here with the same problem including the original ripps uk001 engine. to4z powered. at castle comble the other year it blew a gallon of oil into the tank after 20 laps...?.this one was built by rob himself is very famous. was fitted to a white 33gtr that ran 10,s in nz. bernie uk

I really don't see how a RB26/30 can be any different to a RB26 in terms of oil control. Same head, same restrictors, same oil pump etc...

Also I am not sure about all these one-way valves that are being mentioned - keep it open so it can 'vent' as well as drain..

Vent the sump to the back of the head (it may not act as a drain but more likely relieves sump pressure and allows the oil to travel back down to the sump via the factory oil drains more easily). And have a decent drain back from the catch can to the sump. This will act both as a drain when it needs to, and also as another sump vent when its empty.

Running too small a restrictor at the front surely can't be good for valve spring temps and valve train in general?

I run a 1.5mm front and a big baffled 9L sump and the theory is that even if it does chuck oil out to the catch can it flows straight back down to the sump again.. so who cares. (but yes, avoiding it getting to the catch can in the first instance is the better solution I agree.)

[rockabilly]

good pionts mate, we have built many engines and i too cannot find why the 30 blows oil out. the only design differnce in the two is the windage trays?. one has them and the other does not. i suppose running toyo 888 on track wont help .lol..

[GTR1993]

also no oil squirters on the 30 could push a little more oil up the top??

[Marlin]

OP, do you run a windage tray?

At 8000rpm the breeze coming off the crank counterweights is around 300klm/h. What that wind can do to oil returning from up top shouldn't be underestimated. It can even disturb oil that's lying in the bottom and make it airborn.

I'm suprised more of you guys with high hp big buck engines aren't running dry sumps? It sure makes life easy, and negates The major downfall of a high revving RB.

Edited September 21, 2010 by Marlin

[O2 Autosports]

Thanks for that. Do you have a rear head drain at all?

yes, going to the rear turbo oil drain.(single turbo conversion)

[BoostdR]

I run the Windage trays on my Rb30. So I can safely say they don't fix the issue. I machined the girdle to suit. No oil squirters. As for the check valve, I have had the best result from not using one. I also agree it will stop the crankcase venting with a check valve installed. I can understand however why an off the shelf kit has one as they still use the standard emissions savy PCV and vac lines which would want to suck oil up from the sump.

I have a track day on Sat so will be a good test of the current setup which seems to make a world of difference.

I have a fair wack of oil in the inlet still. I wonder if the previous crankcase pressure was not doing any favours for the turbo oil returns also. You almost need to run a vac line to the sump...through a third catch can ----> that would be even better than just a vent/Filter. It would encourage the head oil to drain and the turbo oil returns.....hmmmmn

So from what I can see. Having a crankcase breather and catch can sump return-----other wise known as an 'open loop' or 'atmo' oil/air separator system is the key to oil control in GTR with over 400kwatw.

Some very good info in this thread. Seems the understanding of our issue is moving to the next level. Also seems like the rear head drain setup that Spool sell should be called a breather/oil return.

Matt

Edited September 21, 2010 by BoostdR

[R32 TT]

I'm suprised more of you guys with high hp big buck engines aren't running dry sumps? It sure makes life easy, and negates The major downfall of a high revving RB.

.....and how would I run my Aircon compressor then?

[R32 TT]

I have a fair wack of oil in the inlet still. I wonder if the previous crankcase pressure was not doing any favours for the turbo oil returns also. You almost need to run a vac line to the sump...through a third catch can ----> that would be even better than just a vent/Filter. It would encourage the head oil to drain and the turbo oil returns.....hmmmmn

Some people do this by venting the catch can to the exhaust system. The speed of the exhaust gases suck the fumes from the catch can. If your sump is vented to the catch can this might help create the vacuum you're looking for.

I haven't done this myself, am only repeating what I think I have read elsewhere so someone might correct me in this..

[BoostdR]

Some people do this by venting the catch can to the exhaust system. The speed of the exhaust gases suck the fumes from the catch can. If your sump is vented to the catch can this might help create the vacuum you're looking for.

I haven't done this myself, am only repeating what I think I have read elsewhere so someone might correct me in this..

I will steer clear of this one, it has smoke screen written all over it...lol

[R32 TT]

I will steer clear of this one, it has smoke screen written all over it...lol

Oh that's right... It was in a James Bond novel I read it!

[BoostdR]

Any info on your warm max oil pressure guys?

[rockabilly]

at 90 degrees on track i see the following, running tomei pump as it came, acl race bearings

1000 rpm 3 bar

2000 rpm 4 bar

3000 rpm 4.7 bar

4000 rpm 5.6 bar

5000 rpm 6.5 bar

6000 rpm 7.4 bar

7000 rpm of gauge 8 bar,but i have a capillary too that shows 8.5 bar

but this piont things are moving fast and its difficult to concentrate on a stupid little gauge in the corner.

Edited September 21, 2010 by rockabilly

[r33_racer]

Yeh you can vent your catch can breather into the exhaust via a 1 way check valve. So back fires wont pressurise your catch can and engine. The fitting needs to be welded at a angle similiar to how you would merge a wastegate outlet to your exhaust. The exhaust flow rushing past creates a vacuum and that opens the 1 way valve and draws any oil/air into your exhaust....However having alot of oil in the can will only lead to copious oil fumes. Only good if you have the oil control sorted and it alleviates the need for air filters on the can.

Best setup is individual lines from cam covers to can and a crankcase vent from inlet side of sump to can and a return from can to exhaust side sump. The way the crank spins, it creates a vacuum on the exhaust side encouraging oil drain (oil return holes are on this side) and return from the head, while the inlet side is what vents the crankcase of blowby pressure. The direction of flow is the same as the crank's clockwise rotation. Similiar principle to windage. Its why crankscrapers always face the crank at a tangent to its swinging arc, from the inlet side. Or why the louvers on windage trays are bent up towards the exhaust side.

Hopefully this will help.

Please excuse my lame paint skills.

Edited September 21, 2010 by r33_racer

[Marlin]

.....and how would I run my Aircon compressor then?

By running the exact same setup as we run on Berry's time attack R34 that's how!

The complete kit is available from High Octane, retains air con

[BoostdR]

Yeh you can vent your catch can breather into the exhaust via a 1 way check valve. So back fires wont pressurise your catch can and engine. The fitting needs to be welded at a angle similiar to how you would merge a wastegate outlet to your exhaust. The exhaust flow rushing past creates a vacuum and that opens the 1 way valve and draws any oil/air into your exhaust....However having alot of oil in the can will only lead to copious oil fumes. Only good if you have the oil control sorted and it alleviates the need for air filters on the can.

Best setup is individual lines from cam covers to can and a crankcase vent from inlet side of sump to can and a return from can to exhaust side sump. The way the crank spins, it creates a vacuum on the exhaust side encouraging oil drain (oil return holes are on this side) and return from the head, while the inlet side is what vents the crankcase of blowby pressure. The direction of flow is the same as the crank's clockwise rotation. Similiar principle to windage. Its why crankscrapers always face the crank at a tangent to its swinging arc, from the inlet side. Or why the louvers on windage trays are bent up towards the exhaust side.

Hopefully this will help.

Please excuse my lame paint skills.

[BoostdR]

great stuff!

[BoostdR]

at 90 degrees on track i see the following, running tomei pump as it came, acl race bearings

1000 rpm 3 bar

2000 rpm 4 bar

3000 rpm 4.7 bar

4000 rpm 5.6 bar

5000 rpm 6.5 bar

6000 rpm 7.4 bar

7000 rpm of gauge 8 bar,but i have a capillary too that shows 8.5 bar

but this piont things are moving fast and its difficult to concentrate on a stupid little gauge in the corner.

This is with a .65mm restrictor? Are your measurements in metric?....just to make sure

[rockabilly]

metric?. my gauge reads in psi i just converted it for you guys.. believe me when i did a compression test this week and the cam covers were of as i was checking valve clearances at the same time, with the cas disconnected and wot the oil that was being pumped to the cams was unbelievable. i suspect with a 1.5 mm in there and 8000rpm there would be a gallon a miniute in them covers, no cam baffle will help that, its no wonder they breath. if i built another i might even reduce it more, its frightening how much oil get up there from such a small hole, god forbid i left both the oil feeds in, the sump would empty..lol