N1 Oil Pump?

[Merli]

So I want to upgrade my oil pump. I don't want any oil starvation issues with this engine. Yes, I have baffle plates and upper oil gallery restrictor already sorted... Last thing I need to organise is an oil pump.

So an N1 oil pump brand new from Nissan is about $500-ish...

Why is the NISMO oil pump for RB26 so much more expensive? The NISMO, Jun, GREX, HKS are all about $1200-$1400...

Has anyone got any flow rates for the N1 oil pump? Here are the flow rates for the standard oil pump and the JUN one.

rpm STD JUN

600 4.4 5.5

2000 15.2 19.5

6000 46.7 58.9

Is the N1 pump that much more inferior to these more expensive ones? I assumed that the N1 oil pump would be better than the NISMO one... I guess not judging by the price?

[Kinks]

Those stickers aren't cheap to produce you know

What purpose does the gallery restrictor fulfill? I'm also not familiar with the level of modification you're doing, but I assume you'd have to be chasing serious power to need an oil pump that costs 2-3 times as much.

google = http://forums.skylinesdownunder.co.nz/arch...ic/29548-1.html

this guy used the N1 pump, if it helps.

[japtaxi]

merli,

have a read thru this thread on pf

http://board.performanceforums.com/forums/...readid=67162465

That'll give you some details on N1 pump and actual usage report from JUN pump.

I guess if I ever need to change oil pump again I'll get JUN pump

[Blitz]

Thanks for that link japtaxi - a few of us have been looking for this information

[Kinks]

Good link.. so if you plan to run 13k RPM you need a JUN pump, merli. But otherwise..

"NB: Any pump has an efficency range, so not only is the rev ceiling important, but also note that the lower watermark point - below the effective range of said pump, you may also have cavitation and surge issues occur. Therefore, in some cases, (such as GTR-700's) you would need to ensure that idle is high enough to ensure you won't have low end flow problems."

so don't overengineer things too much

note that tyndago had the N1 pump and destroyed his motor while pushing hard, but he also had the standard baffling. A JUN pump wouldn't mean shit in this case, because pressure/flow is irrelevant when you're sucking in air

[Merli]

Thanks for the replies so far guys...

Kinks: A standard RB26 pumps too much oil up around the camshafts at high rpm, which doesn't leave enough oil down in the sump and can lead to oil starvation during high cornering loads at high rpm, even with sump baffle plates. (i.e. track situations) An oil gallery restrictor restricts how much oil is pumped around the head and leaves more in the sump.

Japtaxi: Sean was pretty vague in his reply, and we all know Mario is very biased towards JUN ... Having personally visited JUN's workshop and smelting house in Saitama, Japan, I can say without a doubt that Mario is founded in his beliefs that they produce nothing but the best goods and have the equipment to do the best R&D for their products.

However, for the person on a tighter budget, I cannot just jump for the "best option", more so, I have to think of the "best option for my needs", which makes my choice a little harder

If Sean is correct that an N1 oil pump is nothing more than a standard pump with a stronger spring, I don't feel that that is a worthwhile upgrade, and I will need to look at spending that extra money (sigh) for a different pump...

I have JUN sump baffle plates sitting here, so I'm not worried about oil starvation due to oil movement...

Does anyone else have any more experience/information they can share with me on this?

[Kinks]

Ah cool. I had a feeling they did something like that but didn't want to assume so.

I guess the question is what the actual differences are between the normal pump, N1, and the aftermarket ones. Stock pump with a higher pressure rating doesn't sound brilliant, but then Nissan do have quite a decent safety margin in their engineering.

I would have thought that a more powerful oil pump (eg JUN) would also need increased sump capacity (not just baffles) to keep it well fed. After all the more oil you pump into the engine the less you have in the sump - the gallery restrictors reduce the problem a fair bit though I'm sure.

Some more googling:

http://www.automotivehelper.com/topic311.htm

GTR2.7L's running a 500HP motor using an N1 pump

http://forums.skylinesdownunder.co.nz/arch...ic/28255-1.html

claims N1 volume figure is 20-30% above stock, which is pretty much the same gain as the JUN figures you quoted in the first post.

One of the tuning shop pumps would probably be better but don't discount the N1 unless it looks like it can't do the job for your power level

[Duncan]

Merli, shoot HAW001 a pm, he has just put an N1 pump in his race car and would have further details. As I understand there is a small mod you can make to the N1 pump that makes it more reliable....

[Merli]

I would have thought that a more powerful oil pump (eg JUN) would also need increased sump capacity (not just baffles) to keep it well fed.  

Excellent point... Anyone have any idea on this?

Dundan: Cheers mate, I'll shoot him a PM.

[Sydneykid]

Hi Merli, having measured quite a large number of RB pumps what I have noted follows;

*N1 GTR pumps run at higher oil pressure but the same flow as standard GTR pumps.

*I have "adjusted" the pressure relief valve on a standard GTR pump and achieved the same oil pressure as an N1 pump

*N1 pumps are the same dimensions as standard pumps therefore can not flow any more oil than a standard pump does at the same rpm.

*HKS GTR pumps are thicker across the impeller, therefore flow more oil at the same rpm.

*HKS GTR pumps have adjustable oil pressure, so you can run higher, lower or equal to strandard pressure but at higher flow rates.

On our circuit race cars we always increase the capacity of the sump and fit wings and one way baffles. Anybody who spends any time on a circuit should do the same.

Hope that helps

[Merli]

Thanks Sydneykid...

Yes, I have been convinced to do a sump extension. I initally didn't want to, as that meant another week off the road, and I need this car to get around, so I wanted as little shop time as possible...

But explained quite simply:

Standard - 150rwkw - 5 Litre Sump

After - 300rwkw + gas - 5 Litre Sump.

Not the best thing for reliability, so yes, I will be getting a sump extension, to hopefully 7.5 litres, and of course baffle plates.

Thanks for the info on the N1 and HKS oil pumps. I assume the JUN, Nismo and GREX oil pumps will all have similar flow rates and running pressure as the HKS one...

I also heard that the JUN oil pump won't bolt onto the standard crank, and needs the JUN crank?!?!?! That didn't make any sense to me whatsoever, but it came from CRD, the JUN distributors, so who am I to argue?

I found these figures for the HKS pump in the HKS Goodsmaster:

rpm STD HKS

600 3.7 5.0

2000 12.9 17.3

6000 39.9 53.1

The figures for the stock pump differ from what JUN claim (posted in the first post)... Interesting

I also found the price of the HKS oil pump, being 159,600 Yen, which works out to be $2050 at the current exchange rate, without shipping!!!! HOLY CRAP!

I might opt for the NISMO oil pump then, if it has similar flow/pressure to the HKS one, as that's sure to be a bolt-on...

Thanks for the help so far guys, much appreciated!

[Sydneykid]

Hi Merli, I have used a Jun oil pump with standard cranks, RB20, RB25, RB26 and RB30. The pumps need the later model (larger) drive flanges so if you have an early model crank you have to use an adaptor. Jun sell the adaptors, so I don't understand anyone saying they don't fit standard cranks.

This is pretty much the same as most brands of RB oil pumps I have seen, they are/have changed over to the later/larger flange style and you need an adaptor if you have an early/smaller flange crank.

RE Nismo, I haven't seen any differences (look or performance) between Nismo and HKS oil pumps, I wouldn't be surprised if they were both made by the same manufacturer.

Hope that helps some more

[Guest RedLineGTR]

great info guys. Thanks

[Merli]

Thanks again Sydneykid,

Yup, I know about the larger oil pump drive on the R33/R34 cranks, and seeing that I have an R33, I would have assumed a JUN pump would have bolted on, hence my surprise when CRD told me it wouldn't! Oh well..

Great news about the NISMO pump, hopefully I can source one of those for a decent price.

Cheers!

Andrew.

[ed]

Andrew,

Have you looked at the tomei oil pump?

I think it just replaces the internals?

They haven't published any flow rates on their site though.

[PSIKO]

SydneyKid: how can you alter the pressure of the standard pump?

Also, does anyone know where in Australia to get the JUN sleeve kits for the std pumps from, and what they're worth?

[ADM]

Andrew,

How much was your sump extension and who did the work?

Cheers

ADM

[Sydneykid]

SydneyKid: how can you alter the pressure of the standard pump?  

Also, does anyone know where in Australia to get the JUN sleeve kits for the std pumps from, and what they're worth?

Put a higher rate spring in the pressure relief valve.

We bought the oil pump adaptor ring from Nengun.