Oil Control In Rb's For Circuit Drag Or Drift

[Craved]

Is engine oil drain into the sump affected by the pressure within the block?

could putting a external breather on the sump (as i have seen in old holden 5L) to allow it to breath better without having to get to the head and out the head breathers allow for better flow of the oil back into the sump ??

[Cubes]

Is engine oil drain into the sump affected by the pressure within the block?

could putting a external breather on the sump (as i have seen in old holden 5L) to allow it to breath better without having to get to the head and out the head breathers allow for better flow of the oil back into the sump ??

Which is what Rob82 has suggested has an influence over how quickly the oil returns to the sump.

[Craved]

Has anybody tryed venting the sump to atmoshpere/catch can to prevent the pressure build up within the crank.

My thoughts are that with sustained high rpm/load the crankcase is pressurising causing the oil not to drain back to the sump. The oil galleries are below the level of oil which means if the sump is pressurised there is no way for oil to drain back. This is why the mod to drain the back of the head via the welch plug on the rear will work as is it more to do with equalling the pressure differential between head and sump than being a drain - but what happens if the oil level is above the level of the rear drain you going to get the same situation.

The way I see it is if the sump itself is vented then you will never have any issue as all the oil drains back from the head will be more than ample to keep the oil in the sump.

It might be an easier option then lifting the head as well if your enigne is back together.

That's a good solution if blow by is a problem. But that's got zero to do with the fact that the head has insufficient oil return capacity for sustained high rpm. Venting the sump does nothing for that problem.

The oil return is best done to the LHS of the sump. Since the crank turns clockwise, that means the oil is returning into the partial vacuum created by the crank rotation. Hence the oil flows intro the sump. Oil level nothwithstanding.

cheers

ahh found related posts

thinking on this, there is only 1 way the block can breath, and thats through these rear oil returns.

isnt there always some level of blow by anyway? whether this results in oil out the breathers or not doesnt remove the pressure being forced up into the head covers to escape.

[DVS JEZ]

What about this concept of putting some fuel cell foam in the cam covers somewhere?

Can someone explain it to me? Does it work?

Ps I built my engine before this thread was started and didn't pm SK to ask about oil control.

dont worry buddy your not alone, i did the same thing. had my motor running for about 2 months before i knew, now im worried about racing it, so i am gonna pull the motor out this week end.

spewin....

[Guilt-Toy]

We built my RB30DET back in early 2004 - there was only a few pages of the RB30DET thread at that stage.. So it is a learning curve.. I have allready pulled my engine out and put the tomei restrictor in and it caused my lifter issue.. So it will be interesting to see if you guys get the same issues OR maybe my lifters are nearly dead and yours might be ok.

Sydneykid: QUOTE

Lastly oil pump, if the oil pump is not achieving maximum oil pressure (and therefore flow) by 3,000 rpm, then you have an oil pump problem. Revving the engine to higher rpms should not result in higher oil pressure. If it does, then you have an oil pump problem that needs to be fixed.

----

Can you please give me some ideas on how i can test for this. If i need a new oil pump then i will get one for this weekend and change it while i do my lifters and cams and timing belt....

Thanks

****EDIT UPDATE**** the issue was allways with the bottom end. the restrictor had nothing to do with the lifter noise what so ever. I rebuilt the engine with a totally forged bottem end and used the same lifters and oil restrictor and the engine is fine. no ticking no lifer pump nothing.

SO to confirm with everyone no need to worry - using the 1.5m restrictor and totally blocking off the other oil feed works 100% and was not the cause of my issue. Spun bearings was my issue.

Edited January 9, 2007 by Guilt-Toy

[Cubes]

We built my RB30DET back in early 2004 - there was only a few pages of the RB30DET thread at that stage.. So it is a learning curve.. I have allready pulled my engine out and put the tomei restrictor in and it caused my lifter issue.. So it will be interesting to see if you guys get the same issues OR maybe my lifters are nearly dead and yours might be ok.

A learning curve it was and still is.

Did you run 2 x 1.5mm Tomei restrictors or just the one?

I believe the RB25's run 1.5mm restrictors from factory?!?

[Craved]

A learning curve it was and still is.

Did you run 2 x 1.5mm Tomei restrictors or just the one?

I believe the RB25's run 1.5mm restrictors from factory?!?

i'll measure the block i have at home and see.

side note :

nice superman moderator group tag

[rob82]

Lastly oil pump, if the oil pump is not achieving maximum oil pressure (and therefore flow) by 3,000 rpm, then you have an oil pump problem. Revving the engine to higher rpms should not result in higher oil pressure. If it does, then you have an oil pump problem that needs to be fixed.

Keep in mind that a swap to solid lifters will also require a swap to camshafts designed to run with solid lifters.

Hope that has been of some help

cheers

If there is the same oil flow/pressure to the head at 3000rpm as there is at 6000rpm then why dont we have oil return issues at crusie on the highway, as 3000 rpm is where most skylines criuse at 110km/hr? Is this a safe assumption?

[R31Nismoid]

Just on the SBS... Sump Baffle Syndrome

I dont believe there is an oil surge problem that requires a baffled sump for "most" punters.

Certainly none of the GTR's down here have ever had an issue in the mid 300rwkw range as you know Troy

I really dont think for a circuit car much more power is required.

Pretty much all of them are using a stock sump overfilled without one dead motor that im aware of, and they are all on semi's.

The other mods to lessen the flow and increase the return are done as they are built motors, and this stops the good ole "SBS" which seems to me, to be caused by everything else discussed here

Being there is enough oil down below all of a sudden, there is no issue.

Call me crazy, call everyone else down here crazy aswell, but no-one has problems.

[r33_racer]

all you mexicans are crazy There i said it ok, i said it!

What about on slicks and you've invested alot in your engine and you dont wanna take the risk of spinning something or starving something of oil, then a proper extended baffled sump is a much better option then just overfilling by 1L. Ideally a dry sump setup would be nice. Sooner or later someone only doing the bare minimum will suffer. Depends on how 'built' a motor actually is and how well they've done the required mods to allieviate the oil issues.

Call me crazy, and i dont know about many others racing gtsts or gtrs up here but i dont have any problems at all either. Funnily enough i like having 8-9litres of oil in my engine and sump rather then 4-5l. Helps in other ways rather then just constantly submerging the pickup at anyone time on the track.

P.S incase anyone decides to say it....I like being a bananabender!

Edited October 18, 2006 by r33_racer

[Roy]

...by all means, its your motor and if im rebuilding it then i would hope to be doing things only once and will be doing what i understand is required. RWD vs AWD sump seems to be a big difference to boot.

I guess im just being a pigeon by coming in here and sh1tting in a great thread But how much of this is 'critical to an engine" ? I mean if i suppose the restrictors are cheap enough, and the return lines from the back of the head is again cheap enough. But i would hope that will do???

Personally, i was planning on making a proper oil/air seperator and having the return tees to go to drain or return to the engine. Typically i would have it return to the engine, but would like the functionality of running closed to see the amount of oil that is pooling...have even sussed out a relatively compact level switch that i can install in the separator to alarm my data logger when a certain level is reached

[MerlinTheHapyPig]

^ I think stock oil air separators have a valve so that oil can return to the sump when the engine is turned off.

anyway, on a general note, I haven't had any major oil problems in my rb20 (ie i haven't blown an engine due to oil starvation), though i do get alot of blowby at high rpm. I'm running standard sump, slightly overfilled. However after reading this thread, I'm making these mods to the motor i'm currently building.

how can you tell if you are having oil starvation problems? aside from blowing motors or burning out bearings etc?

[Guilt-Toy]

There are 2 issues here

1: all the oil goes up to the top of the engine and you get none down the bottom and it causes bottom end engine failure.

2: all the oil goes up to the top and escapes out of the engine and fills your catch can in seconds.

So putting more oil in the engine could cause more oil to escape into the catch can wouldn't it ?

[Roy]

...LOL, by the time you have put a lot of band aids on the engien you could do things properly...but, are certain rocker covers baffled better then others? I see some GTRs with R31 rocker covers, or are they going for the NISMO LM race look? Or is it perhaps that earlier rocker covers are baffled better and stop oil from making its way into the hoses and into the catch can????

[Craved]

...LOL, by the time you have put a lot of band aids on the engien you could do things properly...but, are certain rocker covers baffled better then others? I see some GTRs with R31 rocker covers, or are they going for the NISMO LM race look? Or is it perhaps that earlier rocker covers are baffled better and stop oil from making its way into the hoses and into the catch can????

perhaps the location of the breathers, on hard launches the GTR breathers at the back of the motor assists any oil in the head to exit the breather and enter the catch can.

[Cubes]

.

[700HP-GTR33]

I like troys idea on making an outside baffle tank that returns the excess oil up top back to the bottom though.

I hate to put restrictors not knowing what they will do in the long run.

Anyway can we all overfill our cars by 1 litre and se if this causes us problem?

This would be a great test.

[N I B]

Ive run 1 litre overfull for 3 years without any problems in a GTR.

[huddy]

i have trouble with oil in the catch can - how do baffles in the cam covers help? and where do i get them from?

(sorry NOOB to this stuff)

thanks

-Matt

[r33_racer]

air/oil seperators have been around for ages...old idea, most performance places should know of them or have them available to buy.

Obviously the whole point of doing the oil mods is to solve the problem rather then making a bandaid fix which is what everyone seems to want to do. So far to date no one has had any long term problems with doing the mods, so obviously its not that bad. If it is im sure we will know about it when someone starts experiencing some problems. Weve had ours running in the race car for around 5-6 months so far with no dramas. But im sure time will tell.

Edited October 19, 2006 by r33_racer