Oil Control In Rb's For Circuit Drag Or Drift

[NXTIME]

I know that there is a company in Japan that makes the original ones, but they aren't cheap.

Someone local should make a batch of them and sell them to all those rebuilding RB26's...

[Sydneykid]

In regards to the RB25 , why is the front feed blocked off and the rear feed restricted but with the other engines its the rear feed that gets blocked off and the front feed get's the restrictor as per sydneykids table ??

It's actually quite logical, VCT heads have 3 oil feeds, front (for the VCT), middle and rear. Since you have to run the front oil feed (otherwise the VCT won't work) it makes sense to block off the middle feed and use the rear. It balances the flow better along the head. For a 2 oil feed head (non VCT) you want to use the oil feed closest to the oil pump, that's the front one, and block off the rear one. Logical isn't it?

we dont know where sydney kid comes up with his ideas but they have been proven to work time after time after time so its a good idea not to ask questions how he comes up with it...

I do the research, come up with the solution to the problem and then we test, test, test. The oil flow mods were originally arrived at in 1999 and have been only slightly revised since, so there are 8 years of testing. They work, everytime, just follow the table.

Merry Xmas

Gary

[Cubes]

I wouldn't bother questioning Garymeister with regards to the oil feed mods.

I did as I was a little worried about the lack of oil due to no feed from the vct and my head machinist recommending against it.

I ended up going with Gary's recommendation (R32 RB25DE head, no-vct, blocked rear, 1.5mm up front) and it works a charm. The only noise I get on start up is a little piston slap for the first second or so as it has always done, then a light slap until its at operating temp. The top end is silent.

4months and still perfectly fine. The rb30det has now clocked a total of 72,000km's and counting with zero oil in the catch can or a smear of oil in the catch cans piping. Extremely happy.

[SATO GTS]

Hello Gary

sorry to question your experience but i am in the process of building a rb25 with forgies and hks cams so i was just wanting to make sure that no oil supply problems would occur.. ITS A RB25 WITH VCT . leave front feed , block middle and restrict rear feed ..

Yes your reply make perfect sence and i do understand it ..

I have a concern with the std restrictors that i pulled out of the block , i only removed the rear. The restrictor itself is of only a small orifice but its what is underneath the restrictor that i am having problems.. the restrictor is roughly 10mm long with a step down that has 3 hole in the bottom that angled into the bottom if it. Underneath that is a drian back valve or what looks like to be . Do you remove the drain back valve aswell or just the restrictor??

If i was to but the restrictor with the valve left in place then once oil pressure reaches the valve then the valve would be shut on the bottom side of the restrictor (tomei 1.5 restrictor) that i am installing and would not let any oil up to the head . i would draw a diagram but it a bit hard to manage.. I have never seen a restrictor like this before and i am very concerned.

I would really like some info on this if possible please

my mob is 0417224107.

thankyou

kyle

[GTRgeoff]

Kyle. I can answer that. You need to be worried about the amount of oil going into the upper area of the head and not the drainback, so just do the upper restrictors as per the guide.

[SATO GTS]

if i could remove the drainback i would but it is lower in the gallery with only a very small wall thicknes that a screw will not bite to too remove it. if i leave it in and then put to new 1.5 mm restrictor in on top of it the valve it may close up on the restrictor and cause no oil to get into the head once it has oil pressure behind it.

have pics of the difference's between the std and tomei restrictor

i am starting to wish i never even pulled the restrictor out and just left it how nissan intended it to be ..

tomei restrictor on the left and the 25 std restrictor on the right

i also have drawings of what i am thinking about doing to overcome this problem.

Edited December 23, 2007 by SATO GTS

[GTRgeoff]

Kyle, most of us just bang the new restrictor in straight on top of the old one.

No-one has had a problem yet mate, so don't try to make it too complicated.

[bnr#@]

Hey, I'm just doing the oil return mod myself in a 32GTR and was wondering what people do with the solid metal lines that run arround the back of the head that feed water and such to the turbos? They are completley in the way...

[Sydneykid]

Hey, I'm just doing the oil return mod myself in a 32GTR and was wondering what people do with the solid metal lines that run arround the back of the head that feed water and such to the turbos? They are completley in the way...

Move them out of the way, bend them carefully and slowly.

Cheers

Gary

[bnr#@]

Bend them back a bit yeah?

[Sydneykid]

Bend them back a bit yeah?

It depends on what style of fitting you are using. With ours, it is simply a matter of movng the oil & water lines down a bit.

Cheers

Gary

[bnr#@]

Making a block with a fitting in it that bolts straight to the back of the head, it requires about 20mm clearance between the head and the water lines, the lines seem to be able to be bent that far out but just woried about the clearance with the firewall. Do you think it will clear?

[Duncan]

sure will. As long as the fitting itself doesn't sit out too far. even then it clears the firewall but is the firs tthing to hit when you tilt the motor to pull it out

re the diameter for the gravtiy drain, if 1/2" isn't enough for an auxiliary drain then we all have lots of challenges. same diameter as the turbo returns for instance

[PHATR32]

hey does anyone have pics of the setup mensioned up top?

the ol 26 is out so i might as well do it......

[bnr#@]

Will take some pix soon and put them up so you guys can see what was done...

[bnr#@]

Here are some pix of what we have done with my gtr with the oil return, the blue line runs down to the sump on the intake sump into a off the shelf fitting that was tapped in and will be secured with two stainless hose clamps each end. Not fully finished yet but gives you guys an idea

[Duncan]

that fittings looks a little small to be honest - what's the diameter of the hose? and since you've run the lines behind the fitting not over or under it you might have clearance problems.

[PHATR32]

duncan, you mensioned using a braided hose, can we use a oil/heat proof rubber instead? can the braided hose get flattened easily incase there are clearance issues? ie have the hose sitting in an oval shape instead of round?

thanks fellas.

steve

[bnr#@]

that fittings looks a little small to be honest - what's the diameter of the hose? and since you've run the lines behind the fitting not over or under it you might have clearance problems.

The inside diameter of the fitting is 12mm I think. It seems as you would have to bend the lines a hell of a lot to be able to run them above or bellow the fitting...

Its using about 20mm more clearance then before with the fitting like that, maybe a little bit more

[Chris Wilson]

Why not just cut and re swage the hard pipes on the turbo side of the block, and run flexible hose to the other side of the engine, routed to avoid any oil return fitting? I intend using a hose of much greater internal diameter, as the drain is purely gravity, and I would like to see at least a 20mm ID pipe down to the sump region. I may use an alloy pipe and flatten it locally if clearance to the bulkhead is an issue. Great discussion, and pics sure help get the ideas over. Excellent stuff