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

[HoWiE_Au]

Oh lets eliminate somthing else too . Dump the oil out of the catch can into a clear jar and let it settle for the day, the water and oil will seperate if theres any condenstation getting into the lines.

[HoWiE_Au]

Just another mate, What Viscosity oil are you running and type ( Full Syn etc..)

[BoostdR]

Just a thought when this engine was built was the clearance between the sump and pickup measured ???. Also is it running the same Valve stem seals ? if so what type are the positive pressure type ?. Yeah maybe even to much volume trying to be delivered. Think of a hose squirting oil into a hole the size of 10 cents and then think about the same size hole but a 1 inch hose feeding oil into it theres a few ideas to make of it . But eliminating other varibles is the way to go. Start by removing your restrictor it sounds stupid but try it, its not going to kill anyone or anything.

Cheers Rob

The pickup was measured to the sump...can't tell you the exact clearance but its reasonably close to the bottom would be 5-15mm off the bottom...I am interested as to why you ask?

It is running new valve stem seals. Genuine nissan

Remove the restrictor?

[BoostdR]

Also empty the catch can and drive around at 2500rpm for say 10 mins , then drive around at 3000rpm + for 10mins and check the catch can . Obviously its going to higher at 3000+ but at least you know its being delivered into the catch can by excess pressure

At low rpm there is minimal oil

at high rpm low boost there is a small amount

at high boost high rpm there is heaps

I have a tap on my PCV line that I close on the track. The other day I left it open and gave it a run. Filled the can to most it has ever...even activated the over pressure valve at the top of the can. I will do so logical tests and give you some direct data.

ie rpm, boost, vac open or closed.

I was running 10W40 I now Have 10W30 for which Its seems worse(more oil coming out)

From what I have read I really need a 1mm head restrictor

Maybe less than the 113psi oil pressure(if I reduce this I may go to 1.1-1.2mm restrictor)

A head drain to equalise pressure to sump and help return

[O2 Autosports]

i have a 1.1mm restrictor and all the other mods, no oil in the can.

[BoostdR]

Oh lets eliminate somthing else too . Dump the oil out of the catch can into a clear jar and let it settle for the day, the water and oil will seperate if theres any condenstation getting into the lines.

There is definately condenstion in the can to..

If i go from 2nd to 5th @ 1.6bar, Nulon full syn 5W30, 1.5mm restrictor, 113psi oil pressure, 8ltrs of oil. It will fill the primary can...over fill it even.

[BoostdR]

i have a 1.1mm restrictor and all the other mods, no oil in the can.

Thats exactely the things I need to hear, real world results. Can I ask some questions

What oil pump?

What oil?

Baffles?

Can setup(with std lines -pvc and turbo inlet return...atmo breather?)

Sump setup?

Power level?

Leak down result?

Much appreciated

Edited September 19, 2010 by BoostdR

[O2 Autosports]

jun

motul 15/50

std cam covers/baffles

4l can with 19mm hose off each cover, 25mm breather to atmo, pcv blocked

hi-octane 8l baffled sump

330rwkw

haven't done leak down test

[BoostdR]

jun

motul 15/50

std cam covers/baffles

4l can with 19mm hose off each cover, 25mm breather to atmo, pcv blocked

hi-octane 8l baffled sump

330rwkw

haven't done leak down test

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

[woolls]

I had the same problem. 7 laps of Symmons would put about 2.5 ltr into the catch can. Its a 25/30. It was just built. the standard rb30 restrictors (I think they are 1.8) was left in. It does have the head drain back to side of block. I tried a few things but had no luck. I ended up running drain on the catch can back to the sump. ran all of 09 season like this.

The start of this year I spun a rod bearing, so It was rebuild time again. this time 1mm restrictors went in. Still runs the back of head drain back to block. I also Put RB 26 covers with mines baffles. pissed off the oil return from catch can to the sump. Had its first race meet today, and not 1 drop of oil in the catch can.

I am running a N1 pump. Edge 10/60 oil.

[BoostdR]

I also feel the associated extra blowby at this power level is making the issue worse. I will give it a run on low boost and see how it goes from 2nd to 5th...be back in few minutes....

[R32 TT]

At low rpm there is minimal oil

at high rpm low boost there is a small amount

at high boost high rpm there is heaps

Hmm

Isn't the answer about size of restrictor and oil pump pressure answered in those three lines above then?

If at high revs and no boost there is only a little then this indicates that the pump and restrictor size are probably ok.... If it suddenly rises when boost comes on, then this says blowby is somehow a factor and you are pressurizing the sump hence the oil can't get back down. Also velocity out the rocker covers must be up at this point which will be a great transport for the oil...

Can you get a map sensor on your sump?

[BoostdR]

I had the same problem. 7 laps of Symmons would put about 2.5 ltr into the catch can. Its a 25/30. It was just built. the standard rb30 restrictors (I think they are 1.8) was left in. It does have the head drain back to side of block. I tried a few things but had no luck. I ended up running drain on the catch can back to the sump. ran all of 09 season like this.

The start of this year I spun a rod bearing, so It was rebuild time again. this time 1mm restrictors went in. Still runs the back of head drain back to block. I also Put RB 26 covers with mines baffles. pissed off the oil return from catch can to the sump. Had its first race meet today, and not 1 drop of oil in the catch can.

I am running a N1 pump. Edge 10/60 oil.

You are running 2 1mm restrictors....front and rear?

I have a drain from the can to dip stick tube but it has a ball valve tap on it. I have a one way valve on order. I filled the can at the hill climb without the ball valve in the can to dipstick tube. The oil would not return untill I swicthed the motor off. I did have the vac still connected at that time.

[BoostdR]

Hmm

Isn't the answer about size of restrictor and oil pump pressure answered in those three lines above then?

If at high revs and no boost there is only a little then this indicates that the pump and restrictor size are probably ok.... If it suddenly rises when boost comes on, then this says blowby is somehow a factor and you are pressurizing the sump hence the oil can't get back down. Also velocity out the rocker covers must be up at this point which will be a great transport for the oil...

Can you get a map sensor on your sump?

I could connect my map sensor from my Apexi PFC boost controller that is connected but not used. I could log then aswell. I agree the increased blowby restricts the oil return...but if you see how hard it is to get oil through a Mines Triple flow baffle there must be a huge amount of oil in the head. I have done a leak down with good results...I think the map sensor idea is great....I am going to see if I can hook it up. Should be easy

[woolls]

You are running 2 1mm restrictors....front and rear?

I have a drain from the can to dip stick tube but it has a ball valve tap on it. I have a one way valve on order. I filled the can at the hill climb without the ball valve in the can to dipstick tube. The oil would not return untill I swicthed the motor off. I did have the vac still connected at that time.

yes 2 x 1 mm resrictors also running vct that has a 1 mm restictor

[BoostdR]

I also feel the associated extra blowby at this power level is making the issue worse. I will give it a run on low boost and see how it goes from 2nd to 5th...be back in few minutes....

Ok i'm back from testing with some very interesting findings and a theory.

I did a 1st to 4th run all the way through the gears turned around and did it again. Pulled over to check the can. It was half full of oil. I left the motor running and opened the ball valve. The oil returned to the sump via the dip stick tube no worries.

I thought since the last setup when I ran with the Catch can oil return to sump opened, was with the std pcv and return to rear turbo inlet vaccum lines connected. Since I currently have no vaccum returns and an atmo breather on my secondary can I thought I may aswell open my ball valve on the primary catch sump return and do the same run as above again. My primary catch can is a Provent 200 which has a fine filter so when there is oil in it, it does take a while to filter through/empty giving me a chance to check it after a run before it goes into the sump.

I did another run 1st to 4th turned around and did it again. Pulled over and quickly checked the Catch can.....no oil! I went for another run and this time was very very quick to stop pop the bonnet and check the can...again no oil!!

I have a couple of theory's.

The sump return being open enables equalisation of sump and head pressure... Even positive pressure on top of the oil instead of below it pushing it up. I expect that would make it easier for the oil to return to the sump since the pressure differential is less from head to to sump. I would expect the sump pressure also could vent out the atmo filter in the Secondary catch can(refer to my setup below)

With the std Vac lines connected to the head in a car pushing 700hp has a hug amount of vac, this causes a larger pressure differential from the head to sump. Which is why I feel higher boost caused more issue's.....from more vac rather than more blowby. Obviously there will be more of both.

I will keep you up to date to confirm it is doing what I think it is. I have a track day on the 25th so will be the best test. I also have a friends RB25/30 with the vac still connected to the catch can(closed system) that does the same thing only on high boost. His leak down was 2.5% Will make the can vent to atom and attach a tube from the catch can outlet to the dip stick tube and see if it is also fixed.

My setup now is. Passenger rocker breather connected to Drives side breather connected to Provent 200 catch can(primary) with return to the dipstick tube. From the Primary catch can to a seconday catch can that has a small filter and a drain pipe connected to a ball valve. The PCV has a tap that I close when its driven hard. The turbo inlet(vac) line is blocked off.

Cheers,

Matt

[r33_racer]

Yeh you only need a good crankcase breather line to your catch can and thats enough to vent the excessive pressure. With the pressure out of the sump, everything else can work as it should.

[HoWiE_Au]

Sounds good mate keep us informed. I was reading a little bit about the rb25/30s oil issue too.

What type of filter is on the catch can? this is normally were the condensation starts.

What type of baffle setup is in the valve cover?.

Can you make up a gauge like a ball type which can keep a highest reading ?. Im thinking you might need to measure sump pressure via having a gauge in the dipstick to check blow by under pressure. You wont get a proper reading in the driveway because its not under load.

The reason i asked about the sump clearance is that at the moment im doing a engine building course in wangaratta and we were taught about doing simple measurements that save a lot of grief in the long run. The closer the sump pickup is to the sump pan it will give you a different oil pressure reading ( i shit you not ) Ive seen cars that had oil pressure issues and one that had a very low oil pressure, We noted it had a small dent in the sump and low behold it was right under the pickup its self ie reducing oil pressure. What u said about 5mm - 15mm is awesome more so 10mm + is ideal.

[BoostdR]

Sounds good mate keep us informed. I was reading a little bit about the rb25/30s oil issue too.

What type of filter is on the catch can? this is normally were the condensation starts.

What type of baffle setup is in the valve cover?.

Can you make up a gauge like a ball type which can keep a highest reading ?. Im thinking you might need to measure sump pressure via having a gauge in the dipstick to check blow by under pressure. You wont get a proper reading in the driveway because its not under load.

The reason i asked about the sump clearance is that at the moment im doing a engine building course in wangaratta and we were taught about doing simple measurements that save a lot of grief in the long run. The closer the sump pickup is to the sump pan it will give you a different oil pressure reading ( i shit you not ) Ive seen cars that had oil pressure issues and one that had a very low oil pressure, We noted it had a small dent in the sump and low behold it was right under the pickup its self ie reducing oil pressure. What u said about 5mm - 15mm is awesome more so 10mm + is ideal.

The filter is on the secondary catch can. and is a small type...about the size of a biscult in dimension. The primary catch can has an internal filter...see pic

The valve covers have Mine's triple flow baffles.

I can hook up my boost sensor and data log the output.

The GTR sump has ridges on the bottom so the pickup physically shouldn't be to close to the floor.

Edited September 20, 2010 by BoostdR

[N1GTR]

What valve do you have on order?