Rb25 Oil Setup?

[James_s14a]

Hi guys just thinking about oiling for my engine. Im hoping to run about 400-450bhp on stock pistons/rods. Car will be street driven with the odd drift/track day and a sensible rev limit, not thrashed off the limiter.

What would you all do in terms of oil pump/ oil restictor/ head drain kit? Baffled sump?

I was thinking a n1 pump, are they necissary?

Any advice welcome.

[KiwiRS4T]

Probably none of the above. Just fit a catch can to your cam cover breathers and see what you collect in it and then reconsider. The stock pump will supply enough oil now and hopefully not too much!

To do any of your suggestions is an engine out job - you may as well wait until you blow it up and then you can think again. If you really can drive sensibly and not get carried away it might hold together for ages.

[James_s14a]

Thanks for the reply. The engine is out now head is off, thats my prediciment.

I dont want to blow it up tbh as there fairly expensive engines over here, (I'm from the UK) or mabie im just tight. Is it worth spending the money for extra insurance or will I just cause myself un necessary headaches for no real benefit? If I just got a new stock pump and no fancy drain kits and what have you I could put the money toward cams or a better ecu ect.

I want the engine to be reliable, that's the main thing. I don't want it to go bang in three months or so.

[kitto]

Hmmm, if the head is off then you may as well do a bit of work to it.

Don't bother with an N1 pump. Especially not a new one as they tend to fail. If your not going to put a crank collar on, just use the stock RB25 oil pump.

Baffled sump is a very good idea IMO, restrictors - does depend on pump size, but if your using a stock RB25 pump, i think 2x 1.5mm restrictors will be good, seeing as its a street and track car and you have hydraulic lifters. Unless you have a NEO engine and in which case your restrictors are approximately 1.27mm factory anyway.

Drilling out the 5x 8mm holes in the block and head to 9.5mm can be a good idea.

Rear head drains, well theres a huge debate on whether it actually does anything or not, some say it doesn't, some say it does, some say its an oil drain, some say it acts as just a breather.

Try and better baffle your cam covers, then plumb them into a well thought catch can.

To prevent failure of the oil pump, i suggest you fit a brand new OEM harmonic balancer when your re-assembling the engine. It is a serviceable part and should be replaced.

There's a lot you can do, but how much time do you have and what do you want to spend.

[KiwiRS4T]

Ok if your engine is already out that changes things a bit.

The problem with drilling the block is that you need to completely strip it so that you can clean it properly afterwards. If you want to do that fine if not I wouldn't worry.

Yes put restrictors in. The SK chart in the oil control thread says block one and put a 1.5 in the other - I would suggest 1.0mm in each (you can get them from me)

Sump baffle kit is a good idea. If you can, drill and tap and plug a hole in the sump as high as possible on the inlet side so you can fit a breather later if you want / need.

Head drain is a waste of time and space.

Presumably you are going to do rings and bearings?

And stick with your stock oil pump.

[James_s14a]

Morning guys, thanks for the input. Ok I will look into getting oil restrictors and a baffled sump. How would i go about making a drain back to sump from my catch can?

I wasn't going to bother with bearings and piston rings, or drilling out the block oil returns tbh as that means fully stripping apart the block. I know if I had the pistons and rods out I wouldn't be able to help myself but forge them, then the engine would never get in the car!

So consensus down there is n1 pumps aren't worth the bother?

[R31Nismoid]

I've run N1 pumps for 8 years, 3 now over 3 builds - don't smash the limiter and you won't break them.

That said, i did smash limiter constantly and never broke one either (on the recent build from 2 years ago, no problems).

But that's another debate entirely really - use the search and form your own opinion on the matter is my best suggestion - there are only a few people with broken ones and a lot without.

[rob82]

I've run N1 pumps for 8 years, 3 now over 3 builds - don't smash the limiter and you won't break them.

That said, i did smash limiter constantly and never broke one either (on the recent build from 2 years ago, no problems).

But that's another debate entirely really - use the search and form your own opinion on the matter is my best suggestion - there are only a few people with broken ones and a lot without.

Yes but I bet your engine builder torqued the crank bolt up to factory spec.....

So many don't - that's where I believe the issue lies, as it will induce a load at 45degrees to the axis of the crank when loose. Problem only really exist on short drive cranks.

[James_s14a]

Imo you treat the n1 pump as a stock one, after all its only a reworked stock unit. Im becoming of the opinion other supporting mods are required to make the most of a n. Making them quite a lot more money for something I probably won't see benefit from

[KiwiRS4T]

Imo you treat the n1 pump as a stock one, after all its only a reworked stock unit. Im becoming of the opinion other supporting mods are required to make the most of a n. Making them quite a lot more money for something I probably won't see benefit from

Quite. The argument about the reliability of the N1 pump is seperate from the question of do you need an upgraded pump and you probably don't.

If you keep the stock pump and put the restrictors in hopefully your catch can will not fill with oil enough to need to drain it back into the sump. The hose from the sump is more to relieve pressure inside the sump (thus promoting the draining of oil back down from the head) and you would run it to the top of the catch can.

[James_s14a]

Spoke to my tuner about this today, one of the highest rated garages in europe.

Was told for my power won't need a restrictor or a rear head drain. The stock front drain on the 25 was said to be enough. He did however advise a n1 due to the extra mass of oil moved. As the car won't see prolonged high revs i think it should be ok on the head pooling issue.

[JonnoHR31]

Spoke to my tuner about this today, one of the highest rated garages in europe.

Was told for my power won't need a restrictor or a rear head drain. The stock front drain on the 25 was said to be enough. He did however advise a n1 due to the extra mass of oil moved. As the car won't see prolonged high revs i think it should be ok on the head pooling issue.

A stock motor will flood the head and starve the pickup if revved for any extended period.

The "drain" at the front of the motor is a breather, not a drain. Any RB build should include drilling out the oil drains, there are no downsides and it helps avoid problems later on, so why not do it?

As said, if your not going to fit a crank collar and get an aftermarket (N1 is not aftermarket) pump then just use a standard 25 pump, they do a good job and are very reliable. Don't buy a new N1 pump, sure some say they're fine, but why pay more for something that's generally less reliable?

I'm sure your tuner is good, but how much experience does he have with building RB engines?

Edited October 3, 2012 by JonnoHR31

[KiwiRS4T]

The problem with drilling out the drains is that you have to strip and clean the block. Putting the restrictors in is 2 minutes work and AU$20 from me or possibly cheaper elsewhere or you could make your own. As I said before I would put at least provision for a sump breather and if I had an engine out with the head off I would put rings and bearings in it.