RB25DET Oil Requirement

[Touge Whore]

Hey guys!

After doing some tests on the RB I currently have in the S14, I have concluded it will need a rebuild. Oil fouling on 5 of the 6 spark plugs is never a good sign. I will be doing a full build with turbo replacement in the near future to hit a RELIABLE 400whp for daily driver and drift. I have been reading that RB's have oil sump issues when rev'ed for long periods at high levels. Some of the solutions include baffled sumps, restrictor/plug on oil galleys, and larger return chambers and lines. Now, on the other hand, I have seen tuners have 400whp with no mention of many of these issues. Most of the people complaining about oil pressure and sump issues were hardcore track/drag cars in excess of 1.5G's on either cornering or WOT. Would the oil galley restrictor and plug with a baffled sump be sufficient for minimizing this oil problem for my specific requirements? Are these truley necessary? Thanks in advance for any help...

References

Oil Control In Rb's For Circuit Drag Or Drift - Skylines Australia (http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/)
RB25DET Tuning - Skyline Owners Forum (http://www.skylineowners.com/forum/showthread.php?t=66975)

[Zacho]

The issue is at high rpm the oil is all pumped to the head and cannot return to the sump fast enough. People have solved this by either boring the returns or restricting certain feeds.

The oil pump drive snout on early rb engines also makes just a few mm contact with the pump. It is also a good idea to upgrade this. it doesn't help that oem oil pump backing plate screws like to back out.

I personally think sump baffles, A restrictor in the feed(s) and at least an inspection of the crank snout should be done for a track duty car. My car is a street car/occaisonal track and I just did the restrictor for oiling mods. I just stay off the limiter.

[Touge Whore]

Yeah, that was my plan. I was going with the drive snout, 1.5mm restrictor with plug for 2nd, and the baffles for sump. You think this is enough to solve the issue for longer rev limit hits around 7.2-7.5k? I also noticed McKinney has the baffled sump that allows for 7qts. Would this be something you would recommend as well? More oil in the sump...

[Sileighty_85]

you should also get the crank collar since you'll be rebuilding ther engine

[Touge Whore]

Thanks Sileighty...that's what I was actually referring to. Does upgrading the crank collar solve the problem with the oil pump drive snout? Are these not the same thing?

[Touge Whore]

This is pretty much what I was planning on the build...just so you guys have a better picture of where this engine is heading.

Engine
N1 Oil Pump
Raw 6 Ext. Crank Collar
Tomei Oil Galley Restrictor
Brian Crower Rods
Wiseco 87mm Pistons
Cosworth Head Gasket
Tomei Poncams
Supertech Valve Spring Kit
Nissan OEM Gasket Kit
Garrett GT3071R
ACL Race Bearings
McKinney Baffled Sump

[smoked240]

I was going to do this to my engine, but It will only be driven on the street and will very seldom see even close to the limiter. I will do it once I pull the engine later and do a complete build from bottom up. right now I just want to get it done and running.

[Zacho]

This is pretty much what I was planning on the build...just so you guys have a better picture of where this engine is heading.

Engine
N1 Oil Pump
Raw 6 Ext. Crank Collar
Tomei Oil Galley Restrictor
Brian Crower Rods
Wiseco 87mm Pistons
Cosworth Head Gasket
Tomei Poncams
Supertech Valve Spring Kit
Nissan OEM Gasket Kit
Garrett GT3071R
ACL Race Bearings
McKinney Baffled Sump


Personally I'd avoid the N1 pump(not saying it is a bad pump per-say), go OEM, or if you want a great upgrade get the reimax gear set.

Upgrading the collar does give you much more contact on the snout/oil pump drive gear(which is a whole separate issue to oil starvation in the sump).

[Touge Whore]

Ok, I was 50/50 on the N1...I've been reading more and people are saying there are issues with the pump and failure. Appreciate the feedback on that.

As far as the snout/drive gear goes...does the Reimax gear set solve this problem? I can't really find too much information on the oil pump snout.

[Zacho]

I'm not sure if you completely understand, so I'll show you some pics to help :D

Above is a RB crank with the short snout. The shiny silver part on the bottom right of the snout is usually all that makes contact with the oil pump. These cranks you can install the collar on.

Below is an RB crank with the long snout.

http://i6.photobucket.com/albums/y250/guishnu/shortnosevslongnosecranks.jpg

The drive gear of the oil pump shown below is what actually contacts the snout.

http://www.reimax.co.jp/pages/products/lower-area/images/05.jpg


So basically it is independent of what oil pump you run. The snout itself has to be upgraded.

[eSco13ar]

ok, so what you are implying is to go with the ka24e turbo set-up...

haha!

what it do josh?! (tougewhore)

[Touge Whore]

Ahhh, yes, the pics connected the dots. Can any machine shop make the snout longer? or do you have to purchase one similar to the collar? Thanks again...

Hector!!! What is up man? Yes, we are going to trade the RB for a K-Turbo setup and call it a day. Haha!