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PRP oil pump gears - RB25/26 vs N1


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Your oil pump has to have some amount of backlash in the gears, otherwise any little bit of a thermal expansion would probably cause the gears to bind and destroy the entire assembly. When you have a rapid transition from acceleration to deceleration like a hard fuel cut I'm pretty sure that the oil pump gears and the collar on the crank are not staying in perfect contact with each other, instead they're changing RPMs at subtly different rates. So the steady state load you'd predict from something like a pull to 7000 RPM is no longer valid, instead you have to consider the maximum relative acceleration and the resulting impulse from impact when that lash is taken up again.

Some sources: http://www.skylife4ever.com/2011/01/real-problem-with-rb26-oil-pump.html

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On 11/27/2021 at 12:05 AM, joshuaho96 said:

Your oil pump has to have some amount of backlash in the gears, otherwise any little bit of a thermal expansion would probably cause the gears to bind and destroy the entire assembly. When you have a rapid transition from acceleration to deceleration like a hard fuel cut I'm pretty sure that the oil pump gears and the collar on the crank are not staying in perfect contact with each other, instead they're changing RPMs at subtly different rates. So the steady state load you'd predict from something like a pull to 7000 RPM is no longer valid, instead you have to consider the maximum relative acceleration and the resulting impulse from impact when that lash is taken up again.

Some sources: http://www.skylife4ever.com/2011/01/real-problem-with-rb26-oil-pump.html

All issues mentioned are mitigated by running billet gears and a long nose crank. My question pertains more to the oil pump housing differences. I already have an RB25 pump housing I wanted to put billet pump gears in. I was wondering if there's any advantage if I purchase an N1 pump instead and put billet gears into that. Even stranger is I found a link (One in OP) that states the RB25 pump housing is actually preferable which I'm wondering why.

 

Thanks

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On 11/27/2021 at 4:04 AM, TurboTapin said:

All issues mentioned are mitigated by running billet gears and a long nose crank. My question pertains more to the oil pump housing differences. I already have an RB25 pump housing I wanted to put billet pump gears in. I was wondering if there's any advantage if I purchase an N1 pump instead and put billet gears into that. Even stranger is I found a link (One in OP) that states the RB25 pump housing is actually preferable which I'm wondering why.

 

Thanks

https://www.gtr.co.uk/threads/n1-oil-pump.565753/#post-5759331
 

The N1 pump has the same flow rate as an RB26 OEM pump, the difference is basically in the gear dimensions and profile.

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On 11/27/2021 at 4:48 PM, joshuaho96 said:

https://www.gtr.co.uk/threads/n1-oil-pump.565753/#post-5759331
 

The N1 pump has the same flow rate as an RB26 OEM pump, the difference is basically in the gear dimensions and profile.

Yea that's also my understanding. That's why I'm presuming there's no gain in purchasing an N1 oil pump housing. The PRP billet pump gears are N1 style gears so whether they're in an RB26 or N1 housing, the advantages remain the same. 

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If you're planning to run N1 style gears, you'll need a RB26 or RB25DET NEO oil pump. They won't fit in a R32/R33 RB25DE/T housing.

Also I suggest you get a brand new pump then fit billet gears to them, this will allow a better fit and also reduce any unwanted movement.

I did the whole N1 gears in a RB25DET NEO pump that had probably 300k km+ on it. Let's say it didn't work out well.

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The only thing "wrong" with N1 pumps is that there appeared to be a period in the latter part of the first decade of this century where they were failing. This is not original N1 pumps that came in engines. This was N1 pumps that came from Nissan as spares. What is not clear is if there was a real problem or if they were being destroyed by clumsy installation/usage, which was rife at that time.

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On 11/28/2021 at 3:17 AM, Dose Pipe Sutututu said:

If you're planning to run N1 style gears, you'll need a RB26 or RB25DET NEO oil pump. They won't fit in a R32/R33 RB25DE/T housing.

Also I suggest you get a brand new pump then fit billet gears to them, this will allow a better fit and also reduce any unwanted movement.

I did the whole N1 gears in a RB25DET NEO pump that had probably 300k km+ on it. Let's say it didn't work out well.

They sell both 81mm and 77mm diameter gears for regular or n1 pumps. My pump doesn't have many km's but I'll verifiy clearances prior. I think I'm going to try the 81mm gears in my RB25 pump. 

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Also food for thought, you buy billet gears, then a new housing and it ends up costing very close to a new Nitto oil pump.

I've done the following:

  • Engine No. 1 - Old housing, new Spool v1.0 gears
    • Gears eventually developed pitting and all sorts of crap
    • Suspect due to clearance issues and gears moved about causing cavitation (broscience)
    • Start up oil pressure issues
  • Engine No. 1 - New Housing, New Spool v2.0 gears
    • Oil pressure issue seem to be resolved
    • No start up oil pressure issues
    • Oil pump worked a bit too good, kept filling the head/catch can, etc. on track days
    • Binned motor from oil starvation
  • Engine No. 2 - Nitto Oil Pump
    • Oil pressure amazing
    • Also have a 5L catch can draining back to sump
    • Nitto Head drain/crank case vent installed
    • Hope to never talk about oil issues again

 

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On 30/11/21 at 11:29 AM, Dose Pipe Sutututu said:

Also food for thought, you buy billet gears, then a new housing and it ends up costing very close to a new Nitto oil pump.

  • Engine No. 2 - Nitto Oil Pump
    • Oil pressure amazing
    • Also have a 5L catch can draining back to sump
    • Nitto Head drain/crank case vent installed
    • Hope to never talk about oil issues again

 

On this, with my new setup not sure if I should run a new catch can, currently have a Hi Octane catch can, believe it’s 2.5 - 3 litre capacity, its plumbed back to the sump. This was fine with my old RB30 setup, that motor had very little blow by, not sure how the new 2.7 will be? Shop wants me to fit a bigger catch can. 
New motor has the new Nitto billet sine drive oil pump. 

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On 30/11/21 at 11:29 AM, Dose Pipe Sutututu said:

Also food for thought, you buy billet gears, then a new housing and it ends up costing very close to a new Nitto oil pump.

I've done the following:

  • Engine No. 1 - Old housing, new Spool v1.0 gears
    • Gears eventually developed pitting and all sorts of crap
    • Suspect due to clearance issues and gears moved about causing cavitation (broscience)
    • Start up oil pressure issues
  • Engine No. 1 - New Housing, New Spool v2.0 gears
    • Oil pressure issue seem to be resolved
    • No start up oil pressure issues
    • Oil pump worked a bit too good, kept filling the head/catch can, etc. on track days
    • Binned motor from oil starvation
  • Engine No. 2 - Nitto Oil Pump
    • Oil pressure amazing
    • Also have a 5L catch can draining back to sump
    • Nitto Head drain/crank case vent installed
    • Hope to never talk about oil issues again

 

Only way to never have oil issues ever again is dry sump 

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On 05/12/2021 at 2:02 PM, Old man 32 GTR said:

Shop wants me to fit a bigger catch can. 

Seems like these days (with massive boost), most workshops are fitting massive catch cans and returning them to the sump.

I've fit my shit box with a ball valve to switch from street duties (no return) to break stock gearbox mode (return to sump).

On 05/12/2021 at 2:37 PM, r32-25t said:

Only way to never have oil issues ever again is dry sump

Or fit a 2JZ lol.

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On 12/4/2021 at 9:48 PM, r32-25t said:

Make enough sense that Porsche come with them factory along with plenty of other cars 

A lot of wasted space in skylines may as well use it for the dry sump 

Right, but those solutions are usually packaged and designed to work nicely. For a street car that ultimately isn't about outright performance doing all the usual wet sump tricks is probably good enough. Maybe the Hi Octane kit is the way to go there but it's hard for me to say whether it's really "no compromises" for a street car when there's no real photos for how it's installed. The mention of having to swap sway bars, power steering pumps, etc... though definitely gives me pause.

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Factory style oil pumps can cause cavitation at high rpm, even as good as the hi octane big sump is even they went to a dry sump in their own time attack car because the only way to guarantee zero oil issues is with a dry sump as my original post stated 
 

For a street car that drives your grandma to bingo it’s “good enough”, but the original person I quoted has every intention of taking their car and cutting laps at the track. 

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