Jump to content
SAU Community

Recommended Posts

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 :)

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..

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...

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.

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.

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.

  • Like 1
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

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. ;)

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?

  • 1 month later...

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 ?

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

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 :P

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 by Sydneykid
  • Like 1

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 by Guilt-Toy
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.

:P Cheers :D

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.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
    • No those pads are DBA too  but they have colors too. I look at the and imo the green "street" are the best.
    • I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
    • I'm not going to recommend an EBC pad. I don't like them. Just about anything else would suit me better. I've been using Intima pads for a while now.
×
×
  • Create New...