Oil Control In Rb's For Circuit Drag Or Drift

[iruvyouskyrine]

What is your question?

[-S-]

I *think* the s2 rb25 is using hydraulic lifters?

[GTSBoy]

53 minutes ago, -S- said:

I *think* the s2 rb25 is using hydraulic lifters?

Well, yes they do.  But the question you ask about Tomei something something.....we don't know what the something something is.

[-S-]

Excuse my ignorance but what does solid type engine means?

[Huzqld]

On 4/11/2017 at 6:36 PM, thebe said:

Afaik the head "drain" works mostly as a sump breather. I dont think its needed if you fit proper sump breathers (and rocker cover breather setup).

Have welded 4 -12 fittings to sump 3 on inlet side one on exhaust side.. Will use one as sump vent. one as drain back. (other 2 are just spares for whatever, I'd rather have it there in case its ever needed instead of pulling motor back out.

Also fitting the head drain/vent. Will bung this off and only use if necessary (doubt it will be)

-12 breathers from cam covers to catch can, and -12 vent back to turbo inlet eventually. 

Cheers for the help and will update on how it goes once I eventually get it together and back to the track.

[R_34]

It means solid lifters opposed to lash type (hydraulics lifters).

[-S-]

Exactly my point. I thought tomei mentioned the restrictors are for solid engines only?

[GTSBoy]

Hell no.  You need to restrict different amounts depending on how big your oil pump is.  There can be no blanket rule on whether to fit them or not based on what type of lifters are in there.

[89CAL]

Yes. There are different restrictors/blanks depending on what the engine is. There is a guide (table) somewhere that tells you whats what

[iruvyouskyrine]

For you because some people don't know what searching is. Here is my combined post of all the info in this thread. Can't believe i madde this over 3 years ago now!

 

On 2014-3-13 at 0:54 AM, iruvyouskyrine said:

Whoops, yes i did mean catch can, corrected it now.

Yes i understand that now. The two goals are to reduce the amount of oil entering the head, and equalize crankcase pressure.

The oiling issue is solved by selecting the appropriately sized oil restrictor/s that vary with each engine set up. What must be taken into account is the head that you are using, and the oil pump that you are using. Heads with hydraulic lifters (IE R33 RB25) require more oil in the head than heads with Hydraulic lifters (RB26, RB25 NEO) and as such larger restrictors (IE providing less oil restriction) are used in those engines.

Here is a slight update on the original Skydneykid table created way back in 2006. It is pretty much exactly as it was just more user friendly and now includes the NEO. I left the RB20 off the table as nobody seems to be interested in them RE oil control issues, questions about them were asked nowhere near as frequently as RB25/26. They can be added back in if you wish.

The other issue is that of crankcase pressurization. The steps taken to achieve this are drilling out the oil returns in the block to 10mm, and giving them a chamfered edge to promote oil drainage. To displace the oil that is in the head, air must be moved into the head allowing the oil to drain (I am going to use the 'turning a drink bottle upside down' analogy here even though its not 100% accurate i think it gives everyone a good idea of what is going on) Increasing the oil drain cross-sectional area by drilling not only promotes oil drainage but gives air a larger path to travel up into the head, which increases drainage yet again.

A Combination of these two mods is a very good start to sorting out the problems associated with RB oil control, and should be the starting point for anyone looking into this.

A good catch can setup will help even further by acting as an equalizer for crankcase pressure and catching any oil that would otherwise be making its way back into the engine. I will use the method that KiwiRS4T has mentioned and others seem to be using with success. Both cam covers are individually run to a catch can mounted at approximately battery height in the engine bay. 2x -10AN fittings are welded onto the sump above the oil level in the sump. One is run to the highest point in the catch can, and the other run to the lowest point. The catch can can then be either vented to atmosphere, or run to another catch can that does the final oil/air separation before being piped back into the turbo intake.

All of the things mentioned above should be supported by other basic modifications such as

• Baffling in the cam covers, whether it be mines baffles or something similar
• Trapdoors in the sump to keen a consistent oil pickup
• Increasing the capacity of the sump
• Using an oil cooler

Even better control of oil would be done by having

• A Nissan N1 oil pump, or any aftermarket item (Nitto, Tomei etc)
• Fitting your standard nissan on N1 pump with billet gears (Reimax, Nitto etc)
• Fitting a crank colllar to your crankshaft to widen oil pump gear engagement
• Running an ACCUSUMP accumulator to control split second oil pressure loss and for the benefit of pre-oiling

Pics below of what SimonR32 has done with his catch can, which is what i was trying to explain in the diagram above.

If you cannot be bothered reading through the entire thread then read these posts, as i feel that they are some of the most important in the thread to get an understanding of what is actually happening inside the engine, which in turn is able to help us create a way in which to solve these problems.

 

http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/page-49#entry6798597

http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/page-49#entry6798648

http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/page-50#entry6929479

http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/page-53#entry7157413

http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/page-54#entry7159347

http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/page-54#entry7181463

http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/page-55#entry7208766

 

 

All the information in this above guide is purely my own thoughts/experiences on the whole RB oil control issue. Please do not take it as gospel and follow it to the letter. As always do your own research and come to the conclusion of what will suit you best based on your own setup.

 

Big thanks to everyone who posted in this thread.

 

[-S-]

I have that pdf file ok (downloaded that like 5 months back! ) so don't go assuming i didn't read through this thread wise ass! That's why i asked to be sure after recently researching and read what tomei posted!

[iruvyouskyrine]

That is not a PDF, that is a post i made in this topic 3 years ago.

The restrictors are absolutely not for solid lifters only. In fact if anything were true it would be close to the oppotsite. The hydraulic lifters require more oil that their solid counterparts, hence you can see in the table that the hydraulic head (RB25) requires a larger restrictor than the RB20/26/Neo.

Edited May 10, 2017 by iruvyouskyrine

[-S-]

Well i was stating the fact that i do know about that spread sheet u shared. (And that i did read about it and not just ask without searching) I downloaded a pdf version from this thread. Only recently i came across what tomei mentioned and was a bit confused. But nonetheless now i can be sure it's OK to use them in hydraulic type lifters.

[iruvyouskyrine]

Go forth and restrict with your new found information! 

[Rb25/240]

So does it matter on a rb25 s1 if u block the middle or the rear does it make a difference?

[-S-]

Follow the guide. .. it's just a guide that is tried and tested. .. or work alongside that guide. ..

 

 

[Rb25/240]

To late lol o well ill let u guys know what happenes 

[-S-]

What did u do?

[Rb25/240]

Put the restrictor in the middle and blocked the back one

 

[-S-]

Did u accidentally or did u intentionally? Lol