Oil Control In Rb's For Circuit Drag Or Drift

[Duncan]

BTW Paul thanks for the reminder. I added my engine blow ups to the engine death thread. As I said none were related to oil control problems - since the first motor I've build (using Gary's recommendations from the first post in this thread), I've had no oiling problems.

#1: first motor

http://www.skylinesaustralia.com/forums/in...t&p=1119558

#2: washer thru the turbos

http://www.skylinesaustralia.com/forums/in...t&p=2541082

#3: fuel pump earth

http://www.skylinesaustralia.com/forums/in...t&p=3498277

#4: radiator

http://www.skylinesaustralia.com/forums/in...t&p=3717505

#5: cracked block/oil gallery in 2nd hand block

http://www.skylinesaustralia.com/forums/in...t&p=4158984

#6: cam clearance (oil pump)

http://www.skylinesaustralia.com/forums/in...t&p=4696960

#7: crap in head galleries (cam snapped)

http://www.skylinesaustralia.com/forums/in...t&p=4696968

Its a bit sad where this thread has gone. last few pages arguing about vent vs drain (not whether it is a good idea or not) has not really added anything except confusion.

[Swiper the Fox]

BTW Paul thanks for the reminder. I added my engine blow ups to the engine death thread. As I said none were related to oil control problems - since the first motor I've build (using Gary's recommendations from the first post in this thread), I've had no oiling problems.

Its a bit sad where this thread has gone. last few pages arguing about vent vs drain (not whether it is a good idea or not) has not really added anything except confusion.

Thanks for the info Dunc's...what a read! Damn how many chinamen have you assainated?

Look its not sad at all...it sheds some light on what is actually occuring inside the hose when performing this mod. Most of the gains installing the rear fitting (which im saying to do if no other venting is used) is from venting pressure and allowing the system the Nissan engineer's designed do its job. There is no confusion...do the mod if you are not venting elsewhere...simple.

Dont just except that all its doing is draining the oil from your head...its simply not doing that job to return the oil...the factory returns are being helped do their job.

[Duncan]

lol my engine builder asked the exact same question about people of chinese descent. I'm just learning as I go, but one thing I am 100% certain of is that building a bottom end properly is a very simple task.

I guess my concern, like I said earlier, is that a well built rb with reasonable boost doesn't breathe that much. yes some motors do, and yes they certainly do under big boost. but this thread was about "circuit, drag, drift" according to the title, and if you are in nsw and doing circuit you are either running standard boost or 2x 32mm restrictors (or you are lofty). drift I've got no idea about except that a single run is about1/2 a lap (say 60 seconds), and drift the same except it only last 11 seconds or more.

if you can fill a catch can or even a head in 11 seconds (or 60 for that matter) you've got some real issues.

none of my engines have ever breathed enough to fill a catch can (I use a 2 part setup with one over the cam covers and another near the battery for excess) even in very long races with sustained high revs, and I've done the same mods as the first post.

I've got no doubt that there are some circumstances where there is more blow by than the average motor (high boost/agressively loose clearances), and I also think in that case you should vent the block not the head.

[NYTSKY]

Duncan,

You should turn all your dead RB engine blocks into fancy coffee tables. You would make a fortune!

[GT-RZ]

Thanks for the info Dunc's...what a read! Damn how many chinamen have you assainated?

Look its not sad at all...it sheds some light on what is actually occuring inside the hose when performing this mod. Most of the gains installing the rear fitting (which im saying to do if no other venting is used) is from venting pressure and allowing the system the Nissan engineer's designed do its job. There is no confusion...do the mod if you are not venting elsewhere...simple.

Dont just except that all its doing is draining the oil from your head...its simply not doing that job to return the oil...the factory returns are being helped do their job.

yep i agree with that perfectly.

The factory re-circ infact is almost a perfect system if a catch can/seperator was introduced in to it (uses one way pcv valve and venturi effect to create vacuum). with the additional connection to the back of the head and larger returns to allow the bottom end to talk with the head easier. Would be flawless IMO.

If you had your own manifolds / piping to achieve the ideal setup you simply need to go out and buy a pcv valve (one that allows hoses to fit either end)

Then run a hose from the cam cover breathers (just link one to the other then run one hose to the catch can/seperator (with an oil drain to the block if you wish, not recommended) then run a hose with an inline pcv valve (could be mounted to catch can if you wish) to the intake just before the turbo (behind pod filter/ AFM) (reason being is that if you have after the turbo when on boost you will not get ANY vacuum at all as your boosting... if it was an N/A you could mount it anywhere as the engine is always sucking and never being 'boosted'.

The Rb25 has a pcv valve in the cam cover but it does not matter if you intend to have an oil drain to the block, reason being that if you just used the cam cover valve and then put a drain from the catch can which links to near the front pod the 'oil drain' from the catch can will be acting as a vent too without any vacuum control. If you don't intend to have a drain back then you can use the one in the cam cover. although the closer the valve to the source of vacuum the better so having it inline with the hose to the intake is better IMO.

Then with this setup you would ideally want the vent/return to the rear of the head to help everything flow around easier. Enlarged oil returns etc would still be a go go.

Where the drain/vent from the head plumbs in to the block is your decision, i think either side will have some benefit but read what's being said and make an educated guess! personally i'm leaning to the intake side wherever is convenient and use it to help vent some pressure up top as the primary goal. (still want to see m speed r34 intake side of engine to see what they did ) someone gotta have a pic!!!!!!

With the above setup a vent from the block directly would not be needed, i think the above is the best solution IMO as the connection to the head allows venting and potential oil return also.

Of any use?

Edited July 5, 2009 by GT-RZ

[PSI Parts]

I haven't been able to track down a clear image of the intake side, however it's interesting to see the changes M-Speed have made over time to the engine's breathing system due to what I can only imagine was some sort of problem with the initial set-up.

Taken in 2006

Taken in 2008

Unknown Date

[Swiper the Fox]

the 2008 M speed set-up is very similar to what im running now.

[GT-RZ]

Yes they have a very nice setup and with the later version seem to have added extra filters rather than have the one which is up to the individual, probably a good idea especially if you plumb it in to re-circ.

interestingly with there setup is the additional brass attachment tapped in to there head connection:

as seen here

which is an addition to the Auto Staff product. it's more than likely just a vac line attached to a gauge to read the pressure (which would be handy?)

As for the re-circ i tend to think that the m speed r34 would re using re-circ especially when it still has the standard throttle body assembly with the balance tube etc which is where the factory pcv valve is located... if you look on both images there is certainly a hose heading from the PCV valve but tracking where it leads to is another case (looks like the factory location, though), there is also hoses under the catch can...

If you do not change your manifold or 'throttle body assembly' with rb26 then the factory recirc setup is as good as any other choice you can make just add in your own catch tank etc that is sealed, that's why above i listed it as 'If you had your own manifolds / piping' you could always try to duplicate the factory system with it's t junction etc but probably not needed.

I might try sending them an email you never know.

Edited July 6, 2009 by GT-RZ

[GT-RZ]

the 2008 M speed set-up is very similar to what im running now.

There is some similarities mainly in the use of multiple filters/tanks but they are using intake vacuum and you vent to atmo. so there system will be venting much more efficiently and more than likely creating internal atmospheric vacuum which we all know the benefits of by now.

They still use the factory pcv setup (one in the balancer tube and the other near the turbos) just with there additional tanks/filters. The other way to achieve the same effect would be to block of the factory pcv valve then run a line directly from the final catch tank to between the turbos/pod with an inline PCV valve although there must be some advantage in doing it the way the factory has otherwise i fail to see the reason behind all the effort.

Not forgetting they have the connection at the rear of the head to aid flow to the covers and as a potential oil escape. wheras you opted for the block vent method, both good options.

With your current setup dirt going with the idea of keeping your current oil drain from your catch tank (since it would at some point be submerged in oil imo due to placement in the sump wing and not acting as a vent all the time)

Plumb another attachment from the block to mid point in your catch tank (or relocate your drain higher up in both tank and block). Then replace the filter on your final tank with a pipe that connects to between the turbo/pod with an inline PCV valve (or thread one in to your catch tank at the start of this pipe).

Due to the large amount of tubing you have making sure it's all air tight would be paramount. Then you will be using a vacuum system VERY similar to m speed r34 with the extensive amount of filtration.

what would be good is to attach a pressure gauge to your system (wherever you like) before you do this and then compare results.

When i get around to setting all this up on my new 26/30! i'll be doing it like above most likely unless i go the hard yards and set up lke m speeds 'factory variation' The only difference to yours is i'll probably fit the head attachment and miss the block vent and try and net both potential gains.

Edited July 6, 2009 by GT-RZ

[Beer Baron]

BB see those large galleries in the rear of the head near the head bolt holes...do you think oil would prefer to drain through these to the sump...or through a tiny little hole through a fitting mounted higher up in the head. ?

Thanks for digging up the pic. A picture tells a 1000 words.

yeah I agrees 100%. and that's the way i've done it too. nice enlarged oil galleries to let it drain nicely. as you know my one was done in japan too and very much in the same vein as m-speeds philosophy. and I think quite possibly on the same track as your head and block theories.

[Sydneykid]

It looks to me like they are using the vacuum take off (on top of the throttle bodies) for the brake booster, which is what I do on the R32. It replaces the PCV valve, which isn't used anymore.

The alloy cylinder on the RHS strut tower looks to ba an oil/air separator, the air then flow from it into the large catch can near the RHS head light. Any oil collected in the separator could be returned to the sump via a fitting on the RHS of the block/ sump or by the dip stick tube.. Which is what I do on the R33.

Cheers

Gary

[Beer Baron]

im re-gigging my setup

i think ill run a extra breather to the dipstick hole now to give that a bash as well

although my heavy breathing may have something to do with my tolerances... seeing as the stock bottom rb30 in it at the moment just clicked over 400k

lol

your heavy breathing is mainly caused by a diet of guiness and meat pies. if you get a catch tank for your nose it may muffle the noise a bit and let gemma get some sleep...

[Beer Baron]

Anyone got a pic of the m speed r34 intake side of the engine???? That will prove if they are using the head connection primariliy as a drain or a vent... If its higher than the centre of the crank it would certainly point towards more of a drain utilising the venturi effect... if not then more of an extra windage escape...

I would like to add that the connection to the head would not be as neccissary if you have a vent from the block directly... Anyone know where you can source some pneumatic one way valves? one that is adjustable and able to open at very low pressures would be ideal...

You could connect that from your vent on the intake side of the block (must be above oil level, dipstick would be ok) or from the breathers on the covers ideally coupled with the head attachment if you don't want a vent from the block. Then attach that directly to the TOP of your catch can that vents to atmo or even better to some sort of vacuum setup, or either plumbed in to intake (factory re-circ would work... and with the one way valve you would not need a BOV if you did not want one...) or exhaust to utilise natural vacuum (venturi effect).

That way you could guarantee no positive pressure is going to enter the crankcase from your escape (engine will make it's own negative pressures depending load of the engine) and it would allow rising positive pressure an escape!

the pic you posted i'm pretty sure shows it. you can see the fitting going into the side of the sump on the intake side.

[Beer Baron]

This picture does not explain it all. if we had a picture of the intake side of the engine it attaches to we can make more educated guesses.

You clearly underestimate some laws of physics. In an engine as we accelerate the g force does increase but what also increases is the windage within the block and with that would also come an increase in vacuum from the potential 'venturi effect' which is exactly how the turbo oil returns work.

This is also exactly how the stock re-circ system works. you increase RPM hence windage and simultaneously the intake air speeds are increased which pulls more vacuum, a perfect cycle.

This is the entire reason why we have no clear answer to this debate, it can be used as a drain or vent on EITHER side of the block depending on it's location relative to the cranks centre.

Fact remains if you added a drain it would help oil problems and if you added a vent it would help oil problems, which way is best is what we will not know without testing (or copying the fastest R34 around a track M speed pics ppl????)

To add to your image 'conclusion' i have attached a link (posted earlier. the link is to the following product:

http://www.rhdjapan.com/jdm-low/Auto-Staff-RB-Engine-Oil-Return-Block-RB25DET-RB26DETT-59928

That is the exact drain used on the image you think clears everything up. They state:

They do not list where it should be attached to the block so it does not help with any part of this discussion but it seems clear on there 'intended' use. weather or not m speed followed this path we don't know. m speed pics

We do know they have it attached to the right side, which proves not much.

PS i am not taking any side. there is arguments from both setups. I do know that if a vent was the primary goal with no additional oil drain needed, a vent directly from the block would be far more efficient.

Maybe the m speed r34 team aim for both as even if it was located as a vent due to the size of the hose any reasonable amount of oil would have no trouble flowing down half the tube whilst the other half was still being used as a vent...

Despite what some think crank 'windage' is not all that strong. the main concern is pressure build up.

i would not take what is on rhdjapan as gospel of what that product is for. they would have written that themselves going by what they 'think' it's designed for. that is not neccisarily what auto staff or m-speed use it for.

[GT-RZ]

This picture does not explain it all. if we had a picture of the intake side of the engine it attaches to we can make more educated guesses.

You clearly underestimate some laws of physics. In an engine as we accelerate the g force does increase but what also increases is the windage within the block and with that would also come an increase in vacuum from the potential 'venturi effect' which is exactly how the turbo oil returns work.

This is also exactly how the stock re-circ system works. you increase RPM hence windage and simultaneously the intake air speeds are increased which pulls more vacuum, a perfect cycle.

This is the entire reason why we have no clear answer to this debate, it can be used as a drain or vent on EITHER side of the block depending on it's location relative to the cranks centre.

Fact remains if you added a drain it would help oil problems and if you added a vent it would help oil problems, which way is best is what we will not know without testing (or copying the fastest R34 around a track M speed pics ppl????)

To add to your image 'conclusion' i have attached a link (posted earlier. the link is to the following product:

http://www.rhdjapan.com/jdm-low/Auto-Staff-RB-Engine-Oil-Return-Block-RB25DET-RB26DETT-59928

That is the exact drain used on the image you think clears everything up. They state:

They do not list where it should be attached to the block so it does not help with any part of this discussion but it seems clear on there 'intended' use. weather or not m speed followed this path we don't know. m speed pics

We do know they have it attached to the right side, which proves not much.

PS i am not taking any side. there is arguments from both setups. I do know that if a vent was the primary goal with no additional oil drain needed, a vent directly from the block would be far more efficient.

Maybe the m speed r34 team aim for both as even if it was located as a vent due to the size of the hose any reasonable amount of oil would have no trouble flowing down half the tube whilst the other half was still being used as a vent...

Despite what some think crank 'windage' is not all that strong. the main concern is pressure build up.

i would not take what is on rhdjapan as gospel of what that product is for. they would have written that themselves going by what they 'think' it's designed for. that is not neccisarily what auto staff or m-speed use it for.

I agree. which is why the discussion did not end when the website was discovered.

Edited July 6, 2009 by GT-RZ

[Beer Baron]

There is some similarities mainly in the use of multiple filters/tanks but they are using intake vacuum and you vent to atmo. so there system will be venting much more efficiently and more than likely creating internal atmospheric vacuum which we all know the benefits of by now.

They still use the factory pcv setup (one in the balancer tube and the other near the turbos) just with there additional tanks/filters. The other way to achieve the same effect would be to block of the factory pcv valve then run a line directly from the final catch tank to between the turbos/pod with an inline PCV valve although there must be some advantage in doing it the way the factory has otherwise i fail to see the reason behind all the effort.

Not forgetting they have the connection at the rear of the head to aid flow to the covers and as a potential oil escape. wheras you opted for the block vent method, both good options.

With your current setup dirt going with the idea of keeping your current oil drain from your catch tank (since it would at some point be submerged in oil imo due to placement in the sump wing and not acting as a vent all the time)

Plumb another attachment from the block to mid point in your catch tank (or relocate your drain higher up in both tank and block). Then replace the filter on your final tank with a pipe that connects to between the turbo/pod with an inline PCV valve (or thread one in to your catch tank at the start of this pipe).

Due to the large amount of tubing you have making sure it's all air tight would be paramount. Then you will be using a vacuum system VERY similar to m speed r34 with the extensive amount of filtration.

what would be good is to attach a pressure gauge to your system (wherever you like) before you do this and then compare results.

When i get around to setting all this up on my new 26/30! i'll be doing it like above most likely unless i go the hard yards and set up lke m speeds 'factory variation' The only difference to yours is i'll probably fit the head attachment and miss the block vent and try and net both potential gains.

their catch tank is not feeding back into the inlet. it's vented to atmosphere.

[GT-RZ]

their catch tank is not feeding back into the inlet. it's vented to atmosphere.

? Why do you think that.

They must just connect a pipe to the PCV valve or 'blowby control valve' as Nissan call it for the joy of it then? I can assure you in the images above, both 2006 and 2009 they are using a re-circ system.

Edited July 6, 2009 by GT-RZ

[Beer Baron]

what would I know? i've only seen the car in person with my own 2 eyes about half a dozen times. I cannot see anywhere that shows a line from the catch tank back to the inlet. can you?

[GT-RZ]

what would I know? i've only seen the car in person with my own 2 eyes about half a dozen times. I cannot see anywhere that shows a line from the catch tank back to the inlet. can you?

In the 2009 image i can see a line that goes back from the catch tank yes. It would be travelling to the other vac line which plumbs in to near the turbo intake, like factory. there is always two lines on the factory setup. one near the manifold and the other near the intake. vacuum lines need only be small, easy to hide away and make things look tidy. Infact m speed joins the manifold PCV valve pipe in to a hard pipe that runs along the firewall. easy to spot?

If you have seen it with your own eyes i would have taken note of where the head connection joins the block! did you? i'm interested!

When the PCV is connected why would they use vent to atmo? have a hose to the PCV for looks or something

Edited July 6, 2009 by GT-RZ

[Beer Baron]

I can't be sure but look at the intake side of the sump. I would guess that that is where the rear head fitting is plumbed into the sump. it's the same pic you posted before.

I have lots of pics of the m-speed engine bay somewhere. if you have time have a look at my japan photo diary. there are bound to be some in there (link in my sig). otherwise if I have time I will try and find some on my other pc.

I also can't see any connection between the rocker covers and the PCV. as sydneykid states it's not being used for that.