Rb26 Oil Control On Circuits

[djr81]

The only spot available currently is the rear oil drain (the issue being getting the line from the catch can to that drain) or the other potential option is we drill and tap the sump on the drivers side.

The catch can took 2L of oil after 7 laps of long track and 3 laps of short track at Barbagallo. That left my sump with just over low on the dip stick which is just enough to be on the safe side considering I have a Greddy extended sump and pickup. So even if nothing drained back during the run I could do 10 laps and still be ok, other stuff on the car is going to give up before then.

Well I would suggest if it did that at Wanners you will have real trouble at Collie. Anyway it is up to you. You can pull the sump off the thing without taking the engine out. Not a fun day at the office but manageable.

Who built your motor out of interest?

[SimonR32]

Well I would suggest if it did that at Wanners you will have real trouble at Collie. Anyway it is up to you. You can pull the sump off the thing without taking the engine out. Not a fun day at the office but manageable.

Who built your motor out of interest?

Stock motor, not built. Doing low 64/54's at Barbagallo so it's not exactly a Sunday drive.

Maybe I'll just avoid Collie

Edited March 5, 2013 by SimonR32

[djr81]

Yeah well the fat rings in the stock motors are actually pretty good at reducing blowby which is the root cause of the problem. Forged engines are more of a problem.

The difference with Wroo/Collie is as follows:
You make blowby/push oil into the heat on the straight - ie when you are accelerating. When cornering at Wroo it is mostly turn right which matches the drain holes in the head of the motor (on the passengers side) So you get some drainage. Also if the catch can is where the battery used to be and is plumbed back it can drain to the sump easilly under cornering load.

Unfortunately Collie is almost all left handers which allows neither of those things to happen. Hence it is much, much harder to sort hte problem there.

So anyone who tells you they have a cure ask them if it worked at Collie and dont beleive them until it has.

Also Collie is much more fun to drive around than Wanneroo.

[SimonR32]

Gav Beer's comment (who runs the same system) was Collie was the worst for oil issues. I think he has been through 3-4 catch can set ups that didn't work well enough. He mentioned that this catch can was the only one that worked for him and he could literally feel the oil draining from the catch can after runs at Collie by putting his hand on the catch can.

I did also do a few laps of long track with boost turned right up to 1.6bar (hit boost cut at 1.74bar about 6 times during 2 laps) so I doubt that would have helped with the blowby. Turned boost down to 1.1bar for the rest of the night but I'm not sure if that helped at all with the problem, for all I know all the oil had already gone to the catch can.

Edited March 5, 2013 by SimonR32

[fatz]

drian back + one way valve

or just knock your reves back 1k

i know which i would choose

[SimonR32]

drian back + one way valve

or just knock your reves back 1k

i know which i would choose

Only rev it to 7500 on the track already so f**k going 1000rpm less.

Just ordered one of these;

http://streetautoparts.com.au/index.php/aeroflow/valves/one-way-flap-valves/aeroflow-one-way-flap-valve-10an-black-af612-10blk.html

Don't know if anyone has used one before but I'll let you know what it's like.

[sav man]

From my experience the Nismo oil air separator don't work that will in practice. I've been chasing oil issues on a 450rwkw rb26 for about 12 months now, we found that oil was pushed from the sump through the Nismo separator back into the catch cans (this was on the dyno), i've put a 1 way valve on it now

Since then i've plumed the dip stick to the cam cover to bleed pressure out of the sump, and even though it's only going through a 1/4" BSP fitting, it made a big difference.

catch cans are a band aid solution, the core of the problem is pressure in the sump.

[sav man]

Only rev it to 7500 on the track already so f**k going 1000rpm less.

Just ordered one of these;

http://streetautoparts.com.au/index.php/aeroflow/valves/one-way-flap-valves/aeroflow-one-way-flap-valve-10an-black-af612-10blk.html

Don't know if anyone has used one before but I'll let you know what it's like.

make sure you remove the spring out of it, otherwise it will never drain back

[fatz]

i have a spare dry sump if you get desperate

[sav man]

have a spare dry sump if you get desperate

It's not my car, and I sugested a dry sump to the bloke a while back and he wasn't keen

[SimonR32]

From my experience the Nismo oil air separator don't work that will in practice. I've been chasing oil issues on a 450rwkw rb26 for about 12 months now, we found that oil was pushed from the sump through the Nismo separator back into the catch cans (this was on the dyno), i've put a 1 way valve on it now

Since then i've plumed the dip stick to the cam cover to bleed pressure out of the sump, and even though it's only going through a 1/4" BSP fitting, it made a big difference.

catch cans are a band aid solution, the core of the problem is pressure in the sump.

Interesting, mine has no issues on the dyno or straight line stuff. Only once it's out on the track does it start filling the catch can.

I do like the idea of plumbing the dipstick to release pressure in the sump, would love some pics on how you went about that. I guess then the only pain in the ass is how to actually measure oil levels?

[sav man]

The RB26 is on my garage floor ATM, so i'll take some pics of that tonight. The catch can return with 1 way valve is in my car, which isn't at my house. I'll be working on my car during the week, so i'll get some pics of the catch can return then.

Spitting oil out on the dyno is pretty rare. The tuner guessed that the Nismo separtor was being used as a vent, and carrying the oil from the turbo drain up to the head.

[djr81]

The RB26 is on my garage floor ATM, so i'll take some pics of that tonight. The catch can return with 1 way valve is in my car, which isn't at my house. I'll be working on my car during the week, so i'll get some pics of the catch can return then.

Spitting oil out on the dyno is pretty rare. The tuner guessed that the Nismo separtor was being used as a vent, and carrying the oil from the turbo drain up to the head.

Oil issues on the dyno are uncommon simply because the engine isnt on song long enough for it to become a problem. It needs to largely fill the cam covers before it starts pumping oil out. They have a reasonable volume which is enough for a pull on a dyno. On the track it is common for them to be on full throttle through the gears and then be subject to lateral and/or longitudinal gees - hence they accumulate oil & sump pressure and start pumping oil everywhere.

Venting the sump is one way of fixing it. It makes up for the lack of cross sectional area in the head of the motor to let the oil return to the sump and the blowby go to atmosphere. How much extra area you need to fix it depends on how much blowby you have.

The problem in all this is it is near on impossible to recreate on the street. Atleast if you are not being a complete spanker. It only happens on the track. Hence many, many RB26's that would otherwise exhibit the problem dont - simply because of the way they are used and not because of the way they are built.

I'd reckon the fix is to use a thicker top ring, fixate on the end gap of that ring and obsess over the run in procedure.

[sav man]

Here is the breather from the dip stick

[SimonR32]

Simple! I had convinced myself it was going to be somehow complicated.

When you said "made a big difference" I assume you mean substantially less oil coming out the breathers?

[sav man]

Yes lots less oil. Before I put that line on the car had 2 x 3l catch cans. It still has them, but the 2nd one only catches the E85 vaper. I have recently added this new -10 line as a breather, which should fix all the breathing problems once and for all.

[SimonR32]

Drilled and tapped the block and rocker cover?

Bit agricultural but I guess if it works who cares!

[sav man]

Yep. L series and SR have crank breathers from the factory

[djr81]

Drilled and tapped the block and rocker cover?

Bit agricultural but I guess if it works who cares!

Rather than mess about with the cam covers you can just run the pipe from the sump into your catch can.

[SimonR32]

Going to drain the catch can to start with and see how it goes, plan is to run a -6 line with one way valve around the back of the head to the rear turbo drain.

If that doesn't work well enough I'll think about running from dip stick to catch can or cam covers

Edited March 6, 2013 by SimonR32