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Joel ... this is from the tomei website

http://www.tomei-p.co.jp/_2003web-catalogu...l-lub_rset.html

says at the bottom that the restrictors should only be used on the RB25 when using solid lifters, and not with lash type...

thoughts?

Joel ... this is from the tomei website

http://www.tomei-p.co.jp/_2003web-catalogu...l-lub_rset.html

says at the bottom that the restrictors should only be used on the RB25 when using solid lifters, and not with lash type...

thoughts?

Well we know the lash type require oil pressure cause they are hydraulic dependant for their movement. But you wouldnt think it would starve them of oil by decreasing the flow. We would be effectively increasing the pressure by reducing the feeds size.

Ok so they fit all but reccomended for only solid type...well that doesnt help the situation ;)

Edited by r33_racer

Hi guys , I would not be ordering a small parallel brass bung from Japan with a 1.5mm (60 thou) hole in it . If you are lucky the basic OD of the thing will very likely be a std brass rod size and only need drilling to size parting off and de burring . Any machine shop could make these for you very easily though you may want more than two to make it worth their while . Actually just had a thought , Nissan L series engines use a similar type of in block head oil restrictor and its just possible that it could fit and work if the ID/OD is suitable .

We have the technology here cheers A .

Bl4ck32,

See how yours goes.. Next time its on the dyno and shaun's gave it a big run quickly unscrew the oil filler cap. My rocker covers were definitely fullish.

Sky30 I believe ran the stock rb30 1.8mm size with an rb20t pump and still wasn't completely happy, I believe he too is looking at going smaller.

Thanks for the obvious tip Discopotato03, I didn't think of such an obvious easy fix (brass rod). ;)

Joel ... this is from the tomei website

http://www.tomei-p.co.jp/_2003web-catalogu...l-lub_rset.html

says at the bottom that the restrictors should only be used on the RB25 when using solid lifters, and not with lash type...

Do remember the rb30 block doesn't run piston oil squirters so in the case of the rb30det, its not that simple to know.

Mine... There's simply too much oil in the head with my setup.

Being...

Rb25det oil pump

R32 non-vct rb25 head

Standard rb20/25 2.4mm restrictors

no piston oil squirters

honed block oil return.

I require smaller oil restrictors. :)

The way I look at it is if there's enough oil for 1 x 1.5mm restrictor to feed the rb26 head + keep the valve springs cool + lube the cam lobes and cam bearings then 2 x 1.5mm restrictors is going to be plenty. ;)

is that 2x0.75 per bank?

when i take the head off the RB30 on monday i'll measure the feed and see what size it is, would have to be pretty spot on for the copper rod to go in there right? like only just fit...

Joel, are you saying that there is more pressure going to the head, since there are no piston squirters to reduce the pressure in the system?

No its only 2 x .75mm per head. :)

Same as how we run 2 x 2.4mm or 2 x 1.8mm (rb30).

You will need to obviously measure the od diamater, punch the old one down as it won't be coming out too easy. :)

---

RE: no oil squirters.

I don't completely understand how decreasing oil flow to the head will increase oil flow or pressure to the main bearings based on the fact that all oil pumps run an internal bypass. Say pressure reaches 100psi, the oil pumps spring bypass opens up and prevents any more pressure being made.

I obviously dont understand the mechanics of it as logic would tell me that if I were to increase the heads oil restrictor size then the oil pump would be flowing more oil to create the same pressure, decrease the heads oil restrictor and the pump would be flowing less to create the same oil pressure.

A smaller head restrictor you may notice higher oil pressure lower in the rpm range which is a good thing with the rb30 as higher power (which is what the rb30 does lower in the rpm) requires higher oil pressure.

All I can see running a smaller restrictor doing is leaving more oil in the sump, less in the head, less chances of lifter pump up, less blowby, not really feeding more oil to the bearings UNLESS the heads restrictor was so big it was preventing the bearings from seeing very little oil pressure due to the oil pump never hitting its internal bypass, which in this case I doubt. I am thinking too much. Don't need to. :P

RE: Patrol RB30

As far as I'm aware they are the same RB30E SOHC.

hi all. this WASN'T covered in this thread (actually used the search :) )....are any of you familiar with the RB30 used in a nissan patrol? think it came carbed. Can this engine be used? thank you

What is it exactly that you want to know?

Let me try a few guesses...............

Was there an RB30 used in Patrols? Yes

Is it the same as RB30 used in Commondoors and and Skylines? Yes

Does it have oil squirters? No

Is it a 4wd block? No

Are they cheaper than Commondoor RB30? No

Are there more of them than Commodoor RB30? No

Are they rare? Yes

Would I bother searching out for one? No

Hopefully one of those answered your question.

:P Cheers :laugh:

Edited by Sydneykid
I know of a couple people that have T'd in to the turbo oil return, they are having no problems.

I know of one person have problems and they are T'd in to the return. It could very well be something else, they are running the N1 high pressure oil pump without modification of oil restrictors. Possibly the real issue.

The problem is the oil from the turbo is rather frothy, it is whipped by the ball bearings and the high revs (<200,000 rpm). So feeding un-aerated oil from the cylinder head return into an already aerated mix is not something I would recommend. The flow would be interrupted and the return would not function as well as it needs to. The ball bearing turbo has restricted oil feed going to it, however notice how large the oil return is. That is to allow for the aerated oil, which has much greater volume than the oil on its own.

That’s why we always have the external oil return from the cylinder head going into the top of the LHS sump wing. Never T’d into the turbo oil return.

I don’t ever use plain bearing turbos, so I don’t know whether they would be any different.

:) cheers :P

Cheerz Gary..

Some one in the know. :dry:

Any chance you would have an opinion on the oil restrictors?

There are 3 answers, all previously posted;

RB26 cylinder head= 2 oil feed galleries between the block and the head

We block one off, same as RB26's are standard

We use a 1.5 mm restrictor in the other

Plenty of oil flow to the camshaft bearings, not too much oil slopping around in the head, getting chucked into the catch can and leaving the sump in short supply.

RB25 with VVT= 2 oil feed galleries between the block and the head

Plus 1 feed to the VVT actuator

We block one off, same as RB26's are standard

We use a 1.5 mm restrictor in the other

Plus leave the VVT oil feed as per standard

Plenty of oil flow to the camshaft bearings and VVT actuator but not too much oil slopping around in the head, getting chucked into the catch can and leaving the sump in short supply.

RB25 without VVT= 2 oil feed galleries between the block and the head

Plus 1 feed to the VVT actuator

We block one off, same as RB26's are standard

We use a 2.0 mm restrictor in the other

Plus block off the VVT oil feed

Plenty of oil flow to the camshaft bearings, no VVT actuator. Not too much oil slopping around in the head, getting chucked into the catch can and leaving the sump in short supply.

Hope that was of some help

:P cheers :P

RB25 without VVT= 2 oil feed galleries between the block and the head

Plus 1 feed to the VVT actuator

We block one off, same as RB26's are standard

We use a 2.0 mm restrictor in the other

Plus block off the VVT oil feed

Plenty of oil flow to the camshaft bearings, no VVT actuator. Not too much oil slopping around in the head, getting chucked into the catch can and leaving the sump in short supply.

Hope that was of some help

:dry: cheers :P

Let me make sure I've got this...

The RB25DET with VVT Disabled.

You run one 2mm oil restrictor as the RB26 does standard and you also block of the VVT oil feed.

Resulting in exactly the same standard setup as the RB26.

So... Myself running a R32 RB25DE head. If it was yours you would block off one of the oil feeds and run 1 2mm feed.

So if I were to run 2 x 1.5's that would still be more than you have suggest for a non vvt head.

I'll add to this my experiences.......

RB30 with R33 25 head. VCT enabled.

On the oil drain issue - head oil return is plumbed into the turbo oil return. Engine has been in and running for nearly 18 months without issue.

On the oil restrictors - I originally built the engine with 2 x 2.4mm restrictors plus the 1.2mm or whatever the VCT is. I had heaps of oil out the breathers if i maintained 4000rpm+ for 5 seconds or more.

About 4 months ago i purchased 2 x 1.5mm Tomei restrictors from Greenline. Punched the old ones down and put the 1.5's on top. So yes they fit the RB30. Oil blown out the breathers is now virtually nil. I did get a little (200ml) after a maintained high speed/rev run but otherwise i haven't checked the catch can since.

Edited by MonstaS4

Awesome MonstaS4,

The two 1.5mm items with non vct should work well. :D

Its always a little iffy when trying new things that really no one (well at least you think there is no one) has had experience with.

One question, which oil pump are you using?

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