Oil Control In Rb's For Circuit Drag Or Drift

[the_tonkau]

yes you will need to plumb a return into the sump i just happen to weld a extra fitting on the sump just incase i needed it in the future just so happened the future wasnt so far down the road lol

Cool. I had a fitting welded to mine last time it was out which I am using for the rear head vent/drain that I can tee into. Looks like the plan. This should save me a lot of work and will actually be a good thing to be able to to tweak the oil pressure easily. I wonder why more people are not this type of setup or are even aware of this solution? Anyway, thanks for sharing the info

[kyle785]

hmm not sure you will be able to tee it in as the rear head oil drain is gravity feed to return and the oil pressure relief is pressure feed return you might find the oil running up the the oil drain from the head a little as there is a fair bit of oil running through the relief valve specialy when in the highter rev's but its all trial and error

[jangles]

Cool. I had a fitting welded to mine last time it was out which I am using for the rear head vent/drain that I can tee into. Looks like the plan. This should save me a lot of work and will actually be a good thing to be able to to tweak the oil pressure easily. I wonder why more people are not this type of setup or are even aware of this solution? Anyway, thanks for sharing the info

hasnt it been covered in this thread earlier that the oil drain is more of a vent? not a drain, therefor forcing oil into a line that isnt full of oil would cause issues? cancelling out the whole reason behind putting in the head vent/drain anyway?

[the_tonkau]

hmm not sure you will be able to tee it in as the rear head oil drain is gravity feed to return and the oil pressure relief is pressure feed return you might find the oil running up the the oil drain from the head a little as there is a fair bit of oil running through the relief valve specialy when in the highter rev's but its all trial and error

My first idea was to use a Y style connection for the up to 40psi of oil pressure/flow and so that it would be pointing "downhill" as such, rather than teeing in at a 45deg angle. Then after a couple of refreshing beers I thought another option might be to use a steel -10 weld-on fitting and fit that to the sump plug hole that's on the side of my custom sump setup.......like you said, trial and error. Good news is that UPS tell me my Peterson regulator is turning up today....excellent.

[rb30_bmw]

I have read this entire thread as the oil pressure issue is what I'm looking for a solid solution for. At some point there was a fairly clear outcome (basically the oil drain from the back of the head into the sump) but by the end, and after some off track wanderings, I'm still not sure.

So ... I have 2 very simple questions that only require a yes or no answer ... since my RB25/30 is assembled and in the car with all ancilliaries fitted.

Q1. Can I do the plumbback mod from the welsh plug to the sump without pulling my engine out as there doesn't seem to be working access to the rear of the head?

Q2. If i'm pulling the engine out and money is no object (obviously it's a factor but for the sake of getting a clear answer) am I better off going for a dry sump conversion?

[jangles]

if you read in this thread it tells you what the rear drain/vent does.

it also tells you you dont need to do it.

cam breathers into intermediate tank, intermediate into main catch, drain to sump,(something like that)

[rb30_bmw]

if you read in this thread it tells you what the rear drain/vent does.

it also tells you you dont need to do it.

cam breathers into intermediate tank, intermediate into main catch, drain to sump,(something like that)

Thanks jangles, I have read this thread many times. Although your solution is mentioned throughout the thread, it has some flaws in it which include not really addressing the issue but instead trying to mitigate the subsequent excess oil result. Obviously without pulling the engine down I have limited options.

I'm pretty sure dry sumping it (although expensive) is a sound solution as it allows the car to be driven on the track without any associated oil issues. Part of the dry sump conversion involves a scavenge tank from the back of head plumbed back into the oil pump so it addresses the excess oil issue without creating any atmospheric component to the oil circuit and assisting with equalized pressure between crankcase and head.

Aithout choosing to go for this option, I believe the other most viable option is to go for an external drain from the welsh plug to the passenger side (RHD) of the sump, block the PCV and move the rocker baffles back to assist the drain back to return oil to the sump.

[jangles]

Thanks jangles, I have read this thread many times. Although your solution is mentioned throughout the thread, it has some flaws in it which include not really addressing the issue but instead trying to mitigate the subsequent excess oil result. Obviously without pulling the engine down I have limited options.

I'm pretty sure dry sumping it (although expensive) is a sound solution as it allows the car to be driven on the track without any associated oil issues. Part of the dry sump conversion involves a scavenge tank from the back of head plumbed back into the oil pump so it addresses the excess oil issue without creating any atmospheric component to the oil circuit and assisting with equalized pressure between crankcase and head.

Aithout choosing to go for this option, I believe the other most viable option is to go for an external drain from the welsh plug to the passenger side (RHD) of the sump, block the PCV and move the rocker baffles back to assist the drain back to return oil to the sump.

better read again then,

i dont want an arguement, just trying to point out whats happening.

the drain you are talking about is not a drain, its a vent, its about equalizing pressure.

therefore, the way i said is what people are doing without any oiling issues, to vent the sump. hardly any oil in the tanks.

ultimately, if you dont have oil restrictors in the block, then everything is bandaid.

from the head to the sump, or from the sump to an intermediate can to covers is all a vent.

i worked this out while reading this thread.

Edited October 13, 2010 by jangles

[bubba]

+1

And to fit that vent you're going to have to pull the head off, I wouldn't be drilling/tapping the head while it is on the engine and if you do want to try that, you'll need to pull the engine out anyway.

So if the head is off, might aswell fit some restrictors to the block

My understanding is that the "vent" from the back of the head gives the gasses an alternative path instead of trying to push up against the oil flow in the factory returns. The vent AIDS the draining of oil through the factory drains.

As jangles said, whether the "vent" goes to the sump or an intermediate catch can, it effectively does the same thing.

[r33_racer]

This may help people understand roughly how the internals work. If anyone has anything to add, feel free! Its probably far from bang on.

[bcozican]

and if you are still filling catch cans etc

fit a VDO oil Scavenger pump to your return from the catch can to the sump and operate it through a missle switch in the cabin, as in some cases a simple line draining back to the sump doesnt flow enough so pump it instead.....

just my opinion coz it worked for me a 2 others have done the same with built engines and heaps of problems and it has solved them (using for drift)

[Supa Steve]

Thanks jangles, I have read this thread many times. Although your solution is mentioned throughout the thread, it has some flaws in it which include not really addressing the issue but instead trying to mitigate the subsequent excess oil result. Obviously without pulling the engine down I have limited options.

I'm pretty sure dry sumping it (although expensive) is a sound solution as it allows the car to be driven on the track without any associated oil issues. Part of the dry sump conversion involves a scavenge tank from the back of head plumbed back into the oil pump so it addresses the excess oil issue without creating any atmospheric component to the oil circuit and assisting with equalized pressure between crankcase and head.

Aithout choosing to go for this option, I believe the other most viable option is to go for an external drain from the welsh plug to the passenger side (RHD) of the sump, block the PCV and move the rocker baffles back to assist the drain back to return oil to the sump.

It addresses the issue as far as i can see as it helps the factory design to do its job. But yes, dry sump is the ultimate solution if you have plenty of folding stuff parked.

[RB30 Ceffy]

just need to bump this to read it without highlighted yellow text :S Been a couple yrs since I visited this thread.

[BoostdR]

Enjoy

[rad100]

so i have a 1.5mm restrictor in my rb25det, forged bottom end, gt3076r, nitto oil pump, mines cam baffles in 26 covers, rear drain to sump, vented catch tank, pcv blocked.

should i keep or remove the spring in the nitto pump before i fit it?

its for track duties.

cheers

[DAS KAMU]

ok

rb26

tomei sump baffle

1.5 oil restrictor front rear blocked

and nothing else

yes or no?

[BoostdR]

so i have a 1.5mm restrictor in my rb25det, forged bottom end, gt3076r, nitto oil pump, mines cam baffles in 26 covers, rear drain to sump, vented catch tank, pcv blocked.

should i keep or remove the spring in the nitto pump before i fit it?

its for track duties.

cheers

Is it a Neo or non neo head.. 1.5mm will be fine for hydraulic buckets.

[BoostdR]

ok

rb26

tomei sump baffle

1.5 oil restrictor front rear blocked

and nothing else

yes or no?

Should be fine with the std oil pump and pressure.

[fast_cav]

Im having a silly problem now after restricting an rb25...Standard pump

The 3 oil restrictors were already 1mm each...

I blocked off the rear one by a tack of weld...middle one was drilled out to 1.5mm but the drill bit only went in 4mm??? VVT one untouched

Strated up all good...Sounds sweet...

But with the knock block on and revs over 3500 there sounds to be a BAD tappet noise...

It gets worse the higher you rev it. Sounds like the lifters are not getting enough oil...Oil pressure in the engine is good...At 3.5k 6bar

Engine sounded all good before The restrictions were done

How far do you have to drill down to into the restrictors to enlarge them to 1.5mm???

I blocked off the back oil way as per RB26 is this wrong???

Is it possible the head is not getting enough oil at high revs causing the lifters to tick??

Thanks...

[JonnoHR31]

25 head needs more oil than 26 due to hydraulic lifters. a single 1mm feed (sounds like you havent drilled the 1.5mm all the way through) with a standard oil pump isnt anywhere near enough for a hydraulic head