Oil Control In Rb's For Circuit Drag Or Drift

[Sydneykid]

regarding restrictors and such, what kind of restrictors should one use on a rb20 using a n1 oil pump?

also ive a shot the back of my head and not sure where i should fit the external drain, advice on both q's is always appreciated.

The upper of the 2 welsh plugs. Look at it from the inside, you can just see it past the camshaft, the oil runs into the Y valley behind the welsh plug.

The lower welsh plug goes into the water jacket.

cheers

[Craved]

SK,

any chance of a pic of one you have setup with the rear drain..

that welsh plug is pretty large, is there usually room behind the head for a 90 deg bend of a earls fitting the entire size of the welsh plug? or do you braze in a smaller fitting then use a 90 to a braided line..

[CruiseLiner]

SK,

any chance of a pic of one you have setup with the rear drain..

that welsh plug is pretty large, is there usually room behind the head for a 90 deg bend of a earls fitting the entire size of the welsh plug? or do you braze in a smaller fitting then use a 90 to a braided line..

same question as craved, my area behind the head in my engine bay is pretty damn tight, and heater hoses r right in the way...

[Craved]

that reminds me , the turbos water feed runs behind the RB25 head ... which means even less room .. looks like the metal line will have to go if this drain is used

[carl h]

lol you think your engine bay is tight?

try cramming a rb into a s chassis, talk about tight.

[Guilt-Toy]

I wish i knew this back in 2004 when I was building my RB30DET.

Its not a huge problem for me but i think installing the baffles will help mine heaps.

[CruiseLiner]

that reminds me , the turbos water feed runs behind the RB25 head ... which means even less room .. looks like the metal line will have to go if this drain is used

the turbo water feed runs around the back of the 26 as well, and yes it would be a damn tight squeeze i reckon. my stagea bay is huge compared to r32's though, so maybe ill fit it if sk does in a 32.

[Turbo Tim]

How big of a problem is this oil issue? Reason being im considering using my essentially stock rb25 for a bit of track work/short sprints, is it going to be a huge issue? Stock limiter is still in place, so I cant spend huge amounts of time up in the revs. Still might be something to think about and might further influence me to thinking about changing for an s14 or similar.

[T04GTR]

for those of uss who are after a good "band aid" fix simply fill the oil leval to the "hump" on the dipstick.

works for me. i tested it using a mechanical oil pressure guage looking for oil surge. at the drags and at wakfield park with good tyres.

anything below the hump and the presure would bounce like crazy.

this is for my street driven gtr with no baffeling etc etc.

so if you are thinking about any track work or nasho runs and the like and drags i strongly sugest you fill er up to the hump.

works out to be about an extra 1.0-1.5 litres extra.

so if you want to keep all of those legs in bed then doooo-it..

ps... it doesnt fill up the catch can any extra either.

[SirRacer]

for those of uss who are after a good "band aid" fix simply fill the oil leval to the "hump" on the dipstick.

works for me. i tested it using a mechanical oil pressure guage looking for oil surge. at the drags and at wakfield park with good tyres.

anything below the hump and the presure would bounce like crazy.

this is for my street driven gtr with no baffeling etc etc.

so if you are thinking about any track work or nasho runs and the like and drags i strongly sugest you fill er up to the hump.

works out to be about an extra 1.0-1.5 litres extra.

so if you want to keep all of those legs in bed then doooo-it..

ps... it doesnt fill up the catch can any extra either.

thats also similar to something that RIPS said on an nz forum. he builds quite anumber of competitive rb30's

i think thats more of a band aid situation thought, getting to the bottom of the problem looks alot better

sydneykid have you had any time to put up your list of reccomendations. if you want you can pm it to me and ill make a chart from it

[T04GTR]

yess. this is for us who couldent be botherd to fab up a 10 litre sump with the usual baffeling

[T04GTR]

but it works for me and others wih no bad outcomes.

but the factory setup is crap and needs atention.. a good oil pressure guage is a very nessesary tool for ironing out this engine destroying fault.

see for your self and im sure youl be alarmed at how much it surges with the oil leval on full.

just in a straight line.

the best test is to do it when its cold going up a hill.

[Destijl]

This might be a stupid question, but do standard SR's suffer from the same oil control problems, or do they handle sustained higher rpms better compared to RBS?

[carl h]

i would imagine that doing the afformentioned mods and adding a sutibly sized oil cooler that the oil system's capacity would be enlarged a bit as well; so perhaps surge would be reduced quite a bit.

while adding an extra quart or so to the sump would work i would think it would cause parastic loss due to excess oil in said sump, no?

[Guilt-Toy]

I know this thread is old. But i am going to revive it.

Reason being is that I am pulling the engine out this weekend and putting a restrictor in.

I got one of those Tomei restrictors from high octane and im not sure what size it is - i think they are 1.5

I am a little confused as to what to do - block the rear oil line completly and then run the 1.5 mm restrictor in the front oil feed or ??

Correct ?

Anyone worked out how to get a fitting put onto the back of the head ???

My combo is RB25DET head with VCT and RB25DET oil pump.

Sydkid can you please confirm ?

[SirRacer]

even though your running a different head than im going to be i look forward to seeing how it works as im going to need to do something oil wise as well

im going to be running an rb25de pump with my rb30. was going to aim for more power however a wee problem is going to force me to just rebuild the engine to standard spec rather than the full forged i would have liked

sydneykid, while your at it what restiction on rb25de (r32) head with the same oil pump. that info would be great

someone sticky this thread

[Sydneykid]

First attempt at a table;

-------------------- -------------------- RB26 -------------------- -------------------- RB25/20 -------------------- -------------------- -------------------- RB25

-------------------- -------------------- No VVT -------------------- -------------------- No VVT -------------------- -------------------- -------------------- VVT

-------------------- -------------------- Front Feed, Rear Feed -------------------- Front Feed, Rear Feed -------------------- VVT Supply, Front Feed, Rear Feed

Standard Oil Pump

Road ----------------------------------- 1.5 mm, Block off, ------------------------------ 1.5 mm, Block off, ------------------------------ Leave, Block off, 1.5 mm,

Drag ----------------------------------- 1.25 mm, Block off, ------------------------------ 1.5 mm, Block off, ------------------------------ Leave, Block off, 1.5 mm,

Circuit/Drift ------------------------------ 1.25 mm, Block off, ------------------------------ 1.25 mm, Block off, ------------------------------ Leave, Block off, 1.25 mm,

RB26 N1 Oil Pump

Road ----------------------------------- 1.5 mm, Block off, ------------------------------ 1.5 mm, Block off, ------------------------------ Leave, Block off, 1.5 mm,

Drag ----------------------------------- 1.25 mm, Block off, ------------------------------ 1.5 mm, Block off, ------------------------------ Leave, Block off, 1.5 mm,

Circuit/Drift ------------------------------ 1 mm, Block off, ------------------------------ 1 mm, Block off, ------------------------------ Leave, Block off, 1 mm,

Aftermarket Oil Pump (Jun HKS Apexi Trust etc)

Road ----------------------------------- 1.25 mm, Block off, ------------------------------ 1.5 mm, Block off, ------------------------------ Leave, Block off, 1.5 mm,

Drag ----------------------------------- 1 mm, Block off, ------------------------------ 1.25 mm, Block off, ------------------------------ Leave, Block off, 1.25 mm,

Circuit/Drift ------------------------------ 1 mm, Block off, ------------------------------ 1 mm, Block off, ------------------------------ Leave, Block off, 1 mm,

Note that all of the above assumes;

1. Standard Nissan clearances

2. Oil cooler (where necessary)

3. Improved oil control in the sump (where necessary) including wings, baffles, one way doors etc

4. External oil return from cylinder head to sump on all circuit/drift cars and drag cars with non standard oil pumps

5. Hydraulic followers in RB20/25's. if changed to solid followers then use RB26 restrictor as above

6. Castrol Edge 10W60 (or equivalent)\

7. Improved oil flow in the cylinder head return galleries through the block.

8. Refer previous posts in this thread

cheers

PS; This guide is for what ever cylinder head you use, the block is irrelevant. Whether you use an RB20/23/24/25/26/27/28/30 bottom end is doesn't matter when it comes to restrictor sizes. It's all about what oil pump you use, what cylinder head and what you use the car for.

Edited May 25, 2006 by Sydneykid

[Guilt-Toy]

Very nice Sydney Kid =)

If anyone can answer a question directly it can be you.

I think this should be put into the RB30 guide thats available as its very important information - it only says restrictors are required but no information on it.

This covers it.

Edited May 25, 2006 by Guilt-Toy

[Sydneykid]

Very nice Sydney Kid =)

If anyone can answer a question directly it can be you.

BTW the middle should read 25/30 im guessing. may want to change it.

I think this should be put into the RB30 guide thats available as its very important information - it only says restrictors are required but no information on it.

This covers it.

Hi, thanks for the thanks. It’s really a selfish thing, I get so many PM's asking what size restrictor to run. So I figure if I made up a table and posted it I wouldn’t get so many PM’s.

The guide is for what ever cylinder head you use, the block is irrelevant. Hence the RB25/20 non VVT column. Whether you use an RB20/23/24/25/26/27/28/30 bottom end is irrelevant when it comes to restrictor sizes.

Cheers

[Guilt-Toy]

I cant wait to get this engine out this weekend and get the lifters changed over and the restrictor put in correctly and get the clutch changed over all in one go and see if i can get the knock sensors running a bit better.

Should be able to make another 80rwhp without any issues!!!

I will get some photos and put them up on where the restrictors go - how it should look etc etc to make things a bit easier for people doing this.

I have decided against running the rear drain as this car is mainly for street - goes to drag strip once a year if its lucky.

Thanks for all your help again Sydney Kid.