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Rb25Det Oil Pumps And Oil Restrictors

mickr33couple

By mickr33couple,
in Engines & Forced Induction

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mickr33couple Community Regular

mickr33couple

Posted
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ok car is been built for street use daily driven, well see the 1/4mile and some hard use here and there

got a rb25det which had a n1 oil pump on there but i am rebuilding the motor and want to know which oil pump am i better off using? as of the storys in regards to the gears in the n1 pump stuffing out, dont wanna rebuild it just to have a stuff oil pump after 1000ks

will be putting extended drive collar on the crank

also with the n1 pumps been high flow what do i have to do with the oil restrictors and the head back to sump drain? anyone shred some light on these points

mods are

je pistons 0.20tho

eagle rods

arp 2000 bolts

acl race bearings

studded head

ff plenum

fmic

power fc

probably gt3540

thanks

Moodles2 Grand Master

Moodles2

Posted
Posted

Different companies make billet gears for N1 pumps: Reimax (japan), JPC (aussie) etc. The standard N1 gears are made from sintered steel and are known to crack & shatter.

As far as the best oil pump money can buy, is probably the Tomei pump because as far as I know it's the only oil pump that has an external oil pressure adjuster, all other pumps need to be taken off to adjust pressure.

With oil control, you really need to read the big thread that's on here somewhere.

Things off the top of my head are:

Enlarging the factory drains (in both the block and head) from 8mm to 9mm-9.5mm, with RB25's I can't remember what is recommended to block whether it's the VCT feed or the middle feed.

I'm not sure what the factory oil restrictors are in RB25's, but I know RB26's come with 2mm restrictors standard.

Switching to RB26 rocker covers so you can use Mine's cam baffles.

Overfilling to 6L-6.5L.

Those rear head drains don't actually work like most people think, instead of draining oil from the head, it helps relieve crankhouse pressure to allow oil to drain back to the sump quicker via the factory drains.

JonnoHR31 Grand Master

JonnoHR31

Posted
Posted

Just get some billet gears for the N1 pump as said.

Don't block the VCT feed in a 25, ever.

Standard 25 feeds are 1.5mm, some 1.2-1.3mm restrictors tapped in over the tops of these should suffice.

KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted

If you haven't already... read the first few and last few (or all if you're so inclined) pages of this thread:

http://www.skylinesaustralia.com/forums/topic/110680-oil-control-in-rbs-for-circuit-drag-or-drift/page__hl__sk+oil+control

SK recommends to leave the VCT, blank off the front feed and put a 1.5 in the rear for drags or 1.0mm for track or drifting. I wouldn't bother with the rear head "drain" but do relieve the internal drains and drill and tap the sump so that you can fit a breather running to a catch can - not the head.

Is your engine going to be fully forged and run to 9000 rpm?

I run an N1 pump (10,000km so far on my RB30/25) but I don't hammer the revlimiter and keep it under 7000 rpm. Depending on use you could be ok with dropping a set of Reimax gears in your pump.

KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted

Unless its a NEO, they are approx 1.27mm each

Do you have any evidence for this? Tomei restrictors are 1.5mm and the ads suggest the stock size is 2.0mm. The only figure I have seen for the RB30 is 1.8mm. Spools restrictors are 1.3mm and I doubt that both Tomei and Spool (and others for that matter) would knowingly make and sell restrictors that are bigger than the standard one.

[To declare my interest I sell the following restrictors: 1.5mm, 1.2mm, 1.0mm and blanking plugs].

KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted

This is for R33 RB25's?

Looks like I watsed money on tomei restrictors then :/

I don't think so - even if stock is 1.8mm then you will reduce flow by more than 30% with Tomei restrictors. If it is 2.0mm you have reduced flow by about 45%

I run 2 x 1.0mm on my RB30/25

kitto Mentor

kitto

Posted
Posted

Do you have any evidence for this? Tomei restrictors are 1.5mm and the ads suggest the stock size is 2.0mm. The only figure I have seen for the RB30 is 1.8mm. Spools restrictors are 1.3mm and I doubt that both Tomei and Spool (and others for that matter) would knowingly make and sell restrictors that are bigger than the standard one.

Ye p. I've got a NEO so I know. It was never opened before I got the engine. Came out of a stock GTT with 39k on it.

Measuring the stock restrictors the size is approx !.27mm.

Nissan pretty much fixed the size if the restrictor on the NEO. Because they use an N1 pump factory, have solid lifters and VCT. They worked out that smaller restrictor was sufficient.

mickr33couple Community Regular

mickr33couple

Posted
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Ok so I have spoken to another engine builder which has told me not to put oil restrictors in the head as it been a hydraulic lifters and cams? He it would make the lifters noise, said it will be find on a rb26 for oil restrictors, he said he will mod the oil galleries and grub screw the oil jets and put drive collar on the crank

brad 110 Collaborator

brad 110

Posted
Posted

You can reduce the rear feed to as small as 0.9 mm, block the centre and leave the front VCt restrictor std. This with hydraulic lifters is fine I have done this many times. The lifters will not be noisy and the VCt will work fine. This will not on its own stop the sump contents from jumping into the catch tank, but is a good start.

MJTru Mentor

MJTru

Posted
Posted

sound just like me years ago, i feel that you just got all the help you just needed from above, good advice mate follow it, and you sound like you did your home work, if i was to add anything get a good damper pulley. have fun boosting lol

best setup crank collar tomia pump 1.5mm rest, and extra head oil return, with good damper. and you should be good.

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