# Oil cavitation: does this sound normal to you?



## Jobi Joba (Apr 19, 2004)

The problem:
If I gently (up to 50% throttle) rev the engine up to the rev limiter (8k rpm), the oil pressure normaly goes up to 6 to 7 bar, along with the revs.
If I floor the pedal, when the engine comes to real life, after the turbo lag (approx 4,300rpm or so), I suddenly lose between 1 and 2 bar of oil pressure when compared to the value I have at the same rpm on part throttle.

BUT, what is interesting is that it's not related to engine load at all. Actually, if I do this test in 4th gear (or even in 5th gear), the oil pressure doesn't really change from its normal value and gently stays above 5 bar.
But when at WOT on 2nd gear, the oil pressure drops below 4 bar at 6k rpm.

So basically, it's related to crank acceleration. It seems the oil pump can't suck enough oil in a little amount of time. Dunno if I make things clear...
Anyway, IMHO, it defo sounds like oil cavitation.

First question: should I worry?
Second question: would an oil grade change help in any way? (thicker or thinner)
Last question: I've seen pics of oil pumps and I wonder if it would be possible to change it without having to completely remove the engine?

And now for those who gonna help, some details:

First of all, my oil system setup:
- N1 oil pump
- Extended sump (Tomei IIRC)
- Oil cooler
- Mobil 0w40 oil at the moment
- std oil filter

Engine: nevermind the specs, here are the dyno results:










The oil pressure metering device I'm using: std gauge and Defi gauge. Both showing the same behaviour (even if std gauge is way less accurate).

Oil pressure @ idle:
- 6 to 7 bar when cold
- approx 2.2bar @ 80/90°C
- approx 1.9bar after about 30min on track

Thx for help!!!


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## Jobi Joba (Apr 19, 2004)

BTW: I never noticed this phenomenon before today when I entered a track day at Spa in Belgium...
Actually, I don't use the car very much and when I use it, I mostly enjoy some in gear launches on highways and not during a very long time...


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## Asim R32GTR (Sep 24, 2003)

Oilpressure drop is caused by the g-force when you accellerate.
You need a baffleplate in your sump.

Asim


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## Jobi Joba (Apr 19, 2004)

Why wouldn't I suffer from this problem when cornering?
RBs are not affected by lateral G forces?


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## mattysupra (Oct 31, 2008)

Mine was doing the same as this. It turned out that it was a faulty oil filter (nissan oil filter! that had just been installed) 

I two thought it was the sump running dry/ baffle extended sump needed but when i realised it would do it in say 4th or 5th gear where there is no where near as much g-force i started looking at other reasons why it was doing it. 

However i have now purchased an accusump to be double safe.


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## kismetcapitan (Nov 25, 2005)

oil filter is the last thing anyone thinks of, but it does have an effect. I switched from generic plain oil filters to K&N high flow oil filters. Made a difference.

I had the same symptoms, but that was before I added an extended sump and set up my Accusump.

Essentially, for whatever reason, under fast engine acceleration (not load-related), the oil pump is running out of oil and ends up sucking oil as fast as it's being returned to the sump. To get a better idea, take a straw and a drink. Then put the straw at the very edge of the drink, and suck. Flow becomes intermittent.

Oil pumps don't like sucking air; you can break your pump.

Quick fix - add another liter of oil, fill your dipstick past the max line up to the hump. Check oil level regularly.

Yes, you should worry. But it's not difficult to fix. It's good you put so much information, it makes it easier to diagnose.

To replace the oil pump, take out the engine. It's the easiest way. Ironically, if you were to do nothing else except change the oil pump to a Tomei, your pressure problem versus crank acceleration would only get worse. The symptoms indicate that the oil pump isn't being fed enough oil in the early gears.

Another way to look at this is that oil is being returned to the sump slower than the pump is pulling oil out. Hence, changing oil grade should have little to no effect on your problem. With 0W-40, what are the oil temperatures that you see? Maximum oil temp your car sees?

I can't imagine that your sump doesn't have a baffle, but if for some reason that was true that could explain some of the problem.

Another very rare problem could be perhaps some kind of blockage with the oil return galleries. But if that were true, it'd be the first time I've heard of it.

Anyways, fill the oil up to the hump on the dipstick. See what that does. When you change your oil, how many liters are you putting into the engine to refill it?


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## Jobi Joba (Apr 19, 2004)

Ok, so it seems I should begin with an oil and filter change. Kismetcapitan, where do you buy your K&N oil filters? (Has anyone tried the Nismo Veruspeed filters?)

Do you guys have pictures of your accusump fitment? Is that a hassle to fit? I thought I understood how it works, but I don't understand why it would help me as my oil pressure is far from dropping to zero. Have I missed a point (possible)?

Oil level: on my dipstick, my oil level (engine hot) was approx 5mm above the max level (it's about 0.3 or 0.4L extra I think). Should have I overfilled a little bit more?

Baffle plate: I guess I have one as lateral G forces doesn't change my oil pressure, no matter how hard I'm cornering. (and trust me, this car is mental! Never seen so much lateral grip!!).

Changing the oil pump: so you don't think it could be cavitation due to crank acceleration? And that an oil pump change would cure the problem? I'd be happy if you're right, cause I don't have time to drop the engine on this car! (which seems to be a hassle BTW) Is the oil pick up directly bolted on the pump?

Max oil temp: yesterday on track, the needle was just below the middle of the gauge, so I would say 110/115°C. But the weather was kinda cold.

How many liters do I put when changing oil? Errrr...will tell you that within a few days! lol Actually I bought the car in April and the oil had just been changed. Now the oil is approx 3,000 miles old, I'll flush it for the first time.


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## Nexen (Jul 19, 2009)

Problem like this is what wrecked my engine . Happened in 2nd gear at hard acceleration . Oil pressure droppped and sounded as if i had run a bearing . Got towed home by a mate . Next morning started car and the noise was there for a couple of seconds then went away . Was convinced but nissan head was knackered but changed head and theres stiil a slight rattle on cylinder6 which has been found to be a small end bearing . Think it was caused by the oil pressure drop . New motor busy being build which will handle alot more power but dont know what to do to prevent this from happening again .


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## mattysupra (Oct 31, 2008)

i have not fitted my accusump yet. I will be doing so next week. Toby has some pics on here of his fitted if you try a search. 


The way the accusump works is that it will pump iol direct into the engine (not the sump) when a certain set pressure activates it. You can set this pressure yourself. I,e it could be set at 1bar and below or maybe 6bar and below.

I think most people set them at about 4bar? So when the engine does drop oil the accusump takes over. When the oil pressure pick up again from the oil pump the accusump will be refilling itself ready for the next drop in oil pressure. 

These are simple to fit. Basically you need to connect one oil pipe. 

Also you can set the accusump up to pre oil your engine before you even start the car. for instance you could put your key in the ignision and you will have 4bar of oil pressure running around the engine without the car being started!


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## Jobi Joba (Apr 19, 2004)

Nexen: have you found what has caused the problem? In my case, I don't think the problem is due to anything else than the oil circuit because tests proved that it's not related to revs nor load... But I wanna solve it before throwing a bearing or something else...


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## Asim R32GTR (Sep 24, 2003)

Have you tried to rev your engine fast up to 7000rpm and watched the oilpressure? 

If the oilpressure is ok when doing this, then it is because of the hard acceleration making the oil move around in the sump. 

Asim


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## Nexen (Jul 19, 2009)

well I only had standard oil pump so hoping n1 oil pump will solve it . reading this thread though seems to happen with n1 aswell . Was thinking of trying a higher velocity sump but googled the accusump earlier and looks like a good idea . Might just buy one while running motor in . Thats when its finished


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## mattysupra (Oct 31, 2008)

Asim R32GTR said:


> Have you tried to rev your engine fast up to 7000rpm and watched the oilpressure?
> 
> If the oilpressure is ok when doing this, then it is because of the hard acceleration making the oil move around in the sump.
> 
> Asim



when mine was playing up it was only doing it when it pleased and mainly after your giving it 3/4 throttle which would explain that it was oil surge in the sump and not picking up oil. 

But like i say, mine turned out to be a faulty NISSAN filter. I only found out it was a faulty filter by chance and that was because i had another one lying around and i tapped an oil pressure gauge into the top of it. 

The problem was solved when using the other oil filter. So i swapped back to the nissan filter (which was brand new at the time -5 miles) and the pressure drop was there again. 

It makes me wonder how many people have fitted an extended sump etc presuming that it was lack of oil pick up? End of the day you would change the oil filter and oil while fitting a sump extension so you would of gotten red of the faulty item without knowing about it! 

BUT! i have still purchased a accusump also to safe gaurd myself against oil surge/lack of pick up or what ever you want to call it. :thumbsup:


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## Jobi Joba (Apr 19, 2004)

Asim: as I said, when reved up on part throttle, no pb. When reved up on high gears, no pb. I only have the problem when reved at full throttle in low gears, when my 500+ engine is pulling the car f*cking hard. So yes, it's related to acceleration. But my main question is which one? Crank acceleration or car acceleration?

At the moment, here is what I've planed to do: change oil and oil filter. (Matty, are u still using std Nissan filters?). And after this change, find a hill and see what happens when going up on part throttle (gravity helping to simulate car acceleration), and going down at full throttle in low gear (gravity helping to reduce oil going backways in my sump).

I'm also looking at accusump products (with 60psi valve)...


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## Asim R32GTR (Sep 24, 2003)

Jobi Joba said:


> Asim: as I said, when reved up on part throttle, no pb. When reved up on high gears, no pb. I only have the problem when reved at full throttle in low gears, when my 500+ engine is pulling the car f*cking hard. So yes, it's related to acceleration. But my main question is which one? Crank acceleration or car acceleration?
> 
> At the moment, here is what I've planed to do: change oil and oil filter. (Matty, are u still using std Nissan filters?). And after this change, find a hill and see what happens when going up on part throttle (gravity helping to simulate car acceleration), and going down at full throttle in low gear (gravity helping to reduce oil going backways in my sump).
> 
> I'm also looking at accusump products (with 60psi valve)...


Ok, i think im having trouble getting my point clear.

Have you tried to rev the engine fast while car is standing still. Just floor the pedal and watch the oilpressure gauge. 
Suerly the revs will go up fast enough, or close to what is happening when you drive the car i 2nd gear.

If the oilpressure is ok, then it is not related to crank, but to the accelleration of the car. 

Asim


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## kismetcapitan (Nov 25, 2005)

K&N oil filters can be bought on eBay, I bought a whole bunch, about two years worth. I was using Nismo Veruspeed filters, but the K&N just seems to flow better. Plus it's a lot bigger. If you do a search, I once posted the model number - the application is for Toyota but it fits onto Nissan just fine.

Also, did you try adding oil so it is around the middle of the hump in the dipstick, above the max line? It's a quick patch fix, but I've gotten into the habit of always going past the max line, even with 4 extra liters of oil in my extended sump as well as Accusump.


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## mattysupra (Oct 31, 2008)

ASIM i understand where you coming from....... and again in my case the car would only do this fault while moving that would indicate acceleration G-force. However it was not in my case and again it makes me wonder if it is the true reason in other peoples cases. 


JOBI, i have stopped using the nissan filter after i found out that my problem was related the filter. I now use a filter from my local motor factors. People say that are not as good but end of the day at least my oil pressure now sits as it should do! 

My mate used to work for a FRAM making oil filters and he has always said that there are many manufactores that they make filters for and there is no difference between the after market ones and the OEM ones apart from outside paint finish! He also makes oil filters for some top tuning names that sell for 3 x the price but are still the same thing. Im starting to belive him! 


And yes, i have taken the car to a steep hill and launched it and drove it hard all the way into 3 numbers while passenegr watch's oil pressure gauge. There is no problem since. 

However, im only running about 450 bhp. The power should be at 600+ after mapping hence i have the accusump also now.


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## Jobi Joba (Apr 19, 2004)

Asim R32GTR said:


> Have you tried to rev the engine fast while car is standing still. Just floor the pedal and watch the oilpressure gauge.
> Suerly the revs will go up fast enough, or close to what is happening when you drive the car i 2nd gear.
> 
> If the oilpressure is ok, then it is not related to crank, but to the accelleration of the car.
> ...


Errr... I feel quite...err... lonely. :chairshot What you suggest ends up to the same result I'll have with the up and down hill test, except that it's way way easier to do!! :thumbsup: Will do that this week and keep you informed. Thx for this simple idea! 

Kismet: will do a serach for the K&N part number. Where have you ordered yours? Ebay?


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## Asim R32GTR (Sep 24, 2003)

Jobi Joba said:


> Errr... I feel quite...err... lonely. :chairshot What you suggest ends up to the same result I'll have with the up and down hill test, except that it's way way easier to do!! :thumbsup: Will do that this week and keep you informed. Thx for this simple idea!
> 
> Kismet: will do a serach for the K&N part number. Where have you ordered yours? Ebay?


I have always used MAN W818/82. Cheap and you can get them from your local carpart store. 

Asim


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## Chris Wilson (Aug 20, 2001)

Load on main bearings with big clearances can affect oil pressure. If I was chasing the problem I'd find a good operator with a variable load rolling road or hub dyno (not an inertia dyno) and run the car up under load to try and mimic RPM versus wheel speed change under hard acceleration on the road. This is a very different test to revving in neutral. If the oil pressure remains stable on the dyno look to oil surge, if it still changes look at the bearing clearances with a view to possibly running less clearance. Too much clearance can cause the main or big end bearings to act as an epicyclic pump and squeeze oil out as they rotate, and they can move a LOT of il to the detriment of oil pressure.


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## Jobi Joba (Apr 19, 2004)

Chris Wilson said:


> Load on main bearings with big clearances can affect oil pressure. If I was chasing the problem I'd find a good operator with a variable load rolling road or hub dyno (not an inertia dyno) and run the car up under load to try and mimic RPM versus wheel speed change under hard acceleration on the road. This is a very different test to revving in neutral. If the oil pressure remains stable on the dyno look to oil surge, if it still changes look at the bearing clearances with a view to possibly running less clearance. Too much clearance can cause the main or big end bearings to act as an epicyclic pump and squeeze oil out as they rotate, and they can move a LOT of il to the detriment of oil pressure.


I thought of mechanical problem such as bearing clearance first...But as I said, when at WOT in 4th gear, thus with a higher load than in 2nd gear, the oil pressure is ok. If it was a bearing clearance problem, as far as I know, I would have seen the oil pressure dropping of a few bars...


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## Asim R32GTR (Sep 24, 2003)

One important thing i may have missed.
What gauge are you using to measure the oilpressure?

Asim


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## Infomotive (Oct 22, 2009)

Test


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## Infomotive (Oct 22, 2009)

Firstly oil filter collapse is the most common cause of sudden unexplained oil pressure loss in rbs. and the first place to check because it leads on to the other likly possibility of worn out thrust bearings. This will cause symptoms described also.
Simply, free reving oil pressure will keep crank central and problem not noticable.
Hard accel/decel in low gears forces crank back and forward opening thrust clearance on oppisite side causing op drop.
Remove oil filter.
Cut open with pipe cutter.
Inspect pleats, if folded on to themselves filter is collapsed.
Lay out element and check for bearing material.
If present check crank endfloat.
Jason


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## Jobi Joba (Apr 19, 2004)

Asim: I have a Defi oil pressure gauge.

Infomotive: why the crank wouldn't move back and forward under heavy load in 4th or 5th gear?


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## Nexen (Jul 19, 2009)

If I get a chance I'll cut mine open tonight and see if this is the case


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## Infomotive (Oct 22, 2009)

The axial g force is a fraction of what 2nd gear is compared to 4th/5th. Check the oil filter. Will tell you alot about the state of your engine.


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## kismetcapitan (Nov 25, 2005)

I once used Renault/Samsung oil filters. Cheap, easy to get, and because they're designed to work on Samsung Motors (betcha didn't know Samsung made cars eh??) VQ35 (and of course screw right onto any Nissan engine) figured it'd be ok. Nope. They suck with an uprated oil pump.


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## blue34 (Jul 28, 2005)

has the cylinder head been fitted with oil restrictors? essential with an upgraded oil pump. I also have an external drain, rear of head back to sump, and trust extended sump.


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## Jobi Joba (Apr 19, 2004)

blue34 said:


> has the cylinder head been fitted with oil restrictors? essential with an upgraded oil pump. I also have an external drain, rear of head back to sump, and trust extended sump.



I have no idea if an oil restrictor has been fitted. I bought the car already tuned (very first time I do that as I'm normaly used to tune engines by myself) and it came from Japan with the engine already tuned like it's today.

I'm interested in your external drain: do you have pics of it?


BTW, can someone tell me if the oil pick up is directly bolted to the oil pump?


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## Asim R32GTR (Sep 24, 2003)

Jobi Joba said:


> BTW, can someone tell me if the oil pick up is directly bolted to the oil pump?


Oil pickup is bolted to the block, about in the middle on the exhaust side if i remember correctly. 

And before anybody else tells you that it is a engine out job, i have done it 2-3 times with the engine in the car, changed the oilpump.

But, the r32gtrs i have done it on was lhd converted, maybe its easier on them.

Asim


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## mattysupra (Oct 31, 2008)

where does this oil resrictor go? Is it head off or does it go some where simple to get to? 

Also as they restrict the oil flow to the head i presume dont they raise oil pressure else where and maybe put more strain on the pump? 



And for the oil filter collapasing , when mine played up it was a brand new oil filter that had covered 0 miles when it first showed the problem.


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## kismetcapitan (Nov 25, 2005)

oil restrictor to the head is about as basic a mod as doing a catback exhaust.

oil flow to the head is already restricted - on a stock RB26, one is blocked completely, and the other has a restrictor with a 2mm opening. That's all the oil that the head is allowed to get...from the factory. Tomei reduces that to 1.5mm, Nismo made restrictors that were even tighter, 1.2mm IIRC (maybe 1.3mm?). Guess cams don't need much oil.


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## blue34 (Jul 28, 2005)

As Toby says: Oil restrictors are fitted to the block and reduce the diameter of the oilway feeding the cylinder head. This helps with the problem of all the oil ending up in the head when fitting an upgraded oil pump.

I did a quick search and this info is taken from one previous thread

"If your intensions are to race, then the dry sump system is the one for you. But for fast road/occasional track l'd go for the tomei pump, sump extension, oil restrictors and maybe head to sump oil return. And for peice of mind fit an accusump"

picture of oil restrictor










The head drain is a custom fabricated outlet that replaces the oil core plug on the back of the head and has a braided hose back down to an inlet on the side of the sump. - sorry don't have any pics to hand.


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## Jobi Joba (Apr 19, 2004)

Asim R32GTR said:


> Oil pickup is bolted to the block, about in the middle on the exhaust side if i remember correctly.
> 
> And before anybody else tells you that it is a engine out job, i have done it 2-3 times with the engine in the car, changed the oilpump.


You got it. I was asking about oil pick-up exactly with that in mind.
So you have managed to slightly drop the oil pan so that the oil pump can be removed easily? Cause it seems that 1cm clearance in the front of the pan would be enough... Was it such a hassle to do?

Matty: as far as I know, the oil restrictor is a head off job...(as you guess when seeing picture)

Blue 34: do you think it would be possible for you to take pics of where you've plugged it in the back of the head? Or, if I find a picture of the back of a removed head, could you show us where the core plug you mentioned is?


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## blue34 (Jul 28, 2005)

head drain mod, early version been refined a bit further since - but you get the idea.


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## Jobi Joba (Apr 19, 2004)

That's what I was afraid of: it's defo an engine out job...

Thx for picture anyway


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## Nexen (Jul 19, 2009)

Does the rb25det also have this oil restictor


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## kismetcapitan (Nov 25, 2005)

Nexen said:


> Does the rb25det also have this oil restictor


yes but the sizes are different. I only really know the RB26 but I do know that someone once posted the restrictor sizes for the RB20, RB25, and RB26 on one of the Australian forums.

you can remove the head without taking out the rest of the engine IIRC. 

I've done every wet sump mod possible...except the head drain. There was a debate on how and where to connect the oil return, and I didn't feel like being experimental with the head drain mod.

Now thinking about it though, although the head drain return plug is welded somewhere on the oil pan (debate is whether oil can flow backwards up this hose)...if the head oil drain is teed into one of the turbo oil drains, I'd do it. I already have a Nismo oil separator teed into the rear turbo oil drain, don't see why I can't drain the head into the front turbo drain.


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## kismetcapitan (Nov 25, 2005)

Asim R32GTR said:


> Oil pickup is bolted to the block, about in the middle on the exhaust side if i remember correctly.
> 
> And before anybody else tells you that it is a engine out job, i have done it 2-3 times with the engine in the car, changed the oilpump.
> 
> ...


did you remove the entire oilpan?? Might very well be an LHD versus RHD thing, are the subframes different? And did you unbolt and pull back the transmission?


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## Nexen (Jul 19, 2009)

Ok mine has 3 oil restrictors in the block . where can I get smaller ones and how do you take the old ones out ? Could make smaller ones at work but need to know size then .


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## Chris Wilson (Aug 20, 2001)

All you ever could wish to know, and more )) about oil restriction in RB25 and RB26 engines:

Oil Control In Rb's For Circuit Drag Or Drift - Skylines Australia


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## kismetcapitan (Nov 25, 2005)

you don't take the old ones out, you just hammer the new ones in over the old ones.


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## Nexen (Jul 19, 2009)

So if the Rb26 already has one of these oil holes blocked , which one is it Front , middle or back ? Can I block the same one on my Rb25 motor


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## Asim R32GTR (Sep 24, 2003)

kismetcapitan said:


> did you remove the entire oilpan?? Might very well be an LHD versus RHD thing, are the subframes different? And did you unbolt and pull back the transmission?


Yes, completely removed the sump. 
Had to move gearbox about 2-3cam back. 

Unbolted the enginemounts, and used a engine lifting thing (dont know the english word) that you put on the edge of each fender, and hook up to the engine with chain. 
Pulled the engine up as far as it came, took out the subframe bolts and used a gearboxjack to lower it as low it could get, easy to remove the pan after that.

Asim


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## Asim R32GTR (Sep 24, 2003)

Jobi Joba said:


> That's what I was afraid of: it's defo an engine out job...
> 
> Thx for picture anyway


If you want to do the oil return mod you need to have the engine out. 

This is how i did it.



















Asim


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## Chris Wilson (Aug 20, 2001)

How do you find the Quarter Master seven and a quarter inch clutch? Is it a twin or triple plate? Thanks.


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## Asim R32GTR (Sep 24, 2003)

Chris Wilson said:


> How do you find the Quarter Master seven and a quarter inch clutch? Is it a twin or triple plate? Thanks.


Well, to put it nicely.. its a motherbitch to drive! haha 
It is a tripple plate. 

Im also using a Tilton Flow Control Valve, wich makes it a little bit softer on quick release of the pedal, but if released slowly, it bites... HARD.
Im used to it now, but anyone else who tries do drive my car just give up.

But then again, it was the only thing at a reasonable price that did the job on my engine, go tired of burnt out twinplate OS clutches :chairshot

Asim


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## Chris Wilson (Aug 20, 2001)

I have a QM twin plate in a Zeus Sports Prototype I race, and it's as smooth as silk, I can potter it around the paddock like a road car, so that surprises me. Is it on a re drilled stock flywheel? My current RB26 engine, which is nearly finished, has a triple plate OS Giken clutch, these have proven very good on a few Supras I have built for people. Thanks for the info.


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## Asim R32GTR (Sep 24, 2003)

Chris Wilson said:


> I have a QM twin plate in a Zeus Sports Prototype I race, and it's as smooth as silk, I can potter it around the paddock like a road car, so that surprises me. Is it on a re drilled stock flywheel? My current RB26 engine, which is nearly finished, has a triple plate OS Giken clutch, these have proven very good on a few Supras I have built for people. Thanks for the info.


There is a big defference between twin and tripple QM clutches. 
Its not that hard to drive, like i said, i manage just fine. 

I very often cruise around i Oslo centrum, and its ok if you know how to drive these kinds of clutches. 

OS tripple is very good, but the price difference is HUGE! 

I bought mine slightly used from a Nascar team, i paid 180USD for the clutch, it came with Ford spline discs, sold them and bought brand new set of discs for 350usd. Thats is total 530usd = 320GBP minus what i sold the ford discs for. So in total it cost me around 220GBP. 

Asim


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## Chris Wilson (Aug 20, 2001)

Cheap clutch, well done! Quarter Master are not well known in the UK, although Tilton is popular. I can SEE little difference between the quality of Tilton and QM clutches, and I have used several QM concentric release bearing kits to good effect.


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## Jobi Joba (Apr 19, 2004)

Asim R32GTR said:


> Yes, completely removed the sump.
> Had to move gearbox about 2-3cam back.
> 
> Unbolted the enginemounts, and used a engine lifting thing (dont know the english word) that you put on the edge of each fender, and hook up to the engine with chain.
> ...


Isn't it possible to just lower the front of the oil pan with less hassle?


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## kismetcapitan (Nov 25, 2005)

Jobi Joba said:


> Isn't it possible to just lower the front of the oil pan with less hassle?


nope. and the oilpan has to come off so that you can reseal it with silicone gasket goop.

My oil pump was once changed using the exact method Asim described. I'd rather pull the engine, about the same amount of labor or a bit more, and you get to look the whole thing over millimeter by millimeter.


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## Jobi Joba (Apr 19, 2004)

K&N oil filter and 10W50 Silkolene oil: ordered!


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## Nexen (Jul 19, 2009)

So who's going to answer my question . Which oil restictor can I block on my rb25 or which one is blocked on the rb26


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## Chris Wilson (Aug 20, 2001)

I have answered it, via the link to the Australian Skyline Forum link, it has been an ongoing and in depth discussion on there. All you could possible need to know to come to your own decision is on there


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## Jobi Joba (Apr 19, 2004)

Today I've decided that the car was in great need of a wash! (it rained last week-end at Spa, so needless to say the car wasn't white anymore!)

So I've tried to floor the engine with the car standing still and gearbox in neutral. Guess what happened? Yes, nothing, the oil pressure doesn't dropp at all.

So it seems that I'm indeed suffering from oil surge...

Next step, oil filter filter change and a flush!

At least I'm kinda happy cause now I know an Accusump will cure this! 

Oh, and BTW: my oil level hasn't moved at all and my catch tank level hasn't raised neither!


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## Jobi Joba (Apr 19, 2004)

Filter and oil received.
Accusump ordered.


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## Asim R32GTR (Sep 24, 2003)

If i were you i would pull the engine and rebuild the sump.

An accusump is not a fix to this problem. In my opinion its just another thing that can go wrong. 

Here is how i did my sump, and i never ever had any issues with oilpressure when driving on the track, street and dragstrip. 














































Asim


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## mattysupra (Oct 31, 2008)

well can i be excused for hijacking your thread with a total random question half way through please? 

My question is for TOBY, I see your from Seoul Korea? May i ask, are you british, american maybe and moved to Seoul Korea? I ask as your english is spot on and would of never of guessed you lived in Seoul Korea! Just intrested! sorry! LOL


Anyway back on with the thread, these extended sumps. They hold a bit more than the standard sump in the dip bit. (does that make sence) Now surely if some kind of lip between top and bottom is there the oil pump is dependant on how much oil its holding in there? 

However without some kind of chamber the extended sumps oil would be forced backwards and leave the sump dry? so the lip needs to be ther to catch some oil? 

So next question. How much oil (not including the standard sump) does the extended sump hold? 

Next question, how much oil does the oil pump suck out the sump in a lets say 20 second foot to the floor moment? 


Is there enough oil in that extended sump to supply 20+ seconds supply of oil?


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## Asim R32GTR (Sep 24, 2003)

There is a constant recirculation of the oil, so the sump never goes dry. Unless you are pumping 8+ liters of oil to the head, and nothing is returning, most likely that would never happen. 

My engine takes about 8liters of oil now, with the trust sump and a oilcooler in the front. 

If im not mistaking the Trust oilpump pumps out 

800rpm = 5.5liter pr minute 
2000rpm = 19.7liter pr minute
6000rpm = 59liter pr minute

Asim


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## Jobi Joba (Apr 19, 2004)

Accusump received! (48h delivery from USA to France! My hat is off for Canton Racing!)

Now, just have to wait a decent weather (i.e. without rain) to fit everything on my pride and joy!

Asim: dropping the oil pan is a hassle compared to fitting an Accusump. BTW, I already have an oil pan extension. I think the Accusump should cure the problem.

Anyway, I'll let you know!


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## Jobi Joba (Apr 19, 2004)

I got news!
The engine is flushed.
Good news:
- my oil pressure reading is defo really accurate as I have a full Defi gauge kit, including the sensor (wasn't 100% sure).
- the engine won't overheat: I have a huge oil rad!! (Greddy kit, with thermostatic plate)
Bad news:
- the oil filter is a b*tch to remove!!
- actually I don't have any extended sump...  The car was supposed to have one but now I've flushed the car for the very first time, now I can tell it: my oil pan is std. This explains the surge problem.

I've drilled a hole to run the oil line for the accusump which will be fitted by the driver's seat. Trust me, drilling a hole in the pedal area is a true hassle...

Anyway, if I get my hands on all the plumbing required by saturday, I'll be able to tell you by the end of the week-end if everything is now ok with new oil, new oil filter, accusump, and overfilled oil pan!


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## freakazoid3 (Jan 19, 2008)

Where are you installing the accusump in the oilsystem?


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## Jobi Joba (Apr 19, 2004)

On the return line of my oil rad.


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## Jobi Joba (Apr 19, 2004)

After some issues fitting the Accusump (due to the K&N oil filter differences with the std small unit which was previously fitted on the engine), here are the final results:
- K&N oil filter + oil change: same problem I had
- Silkolene 10W50: better oil than the 5W40 I had, for sure. But still losing oil pressure under hard acceleration
- Accusump: GREAAAAAAAAAAAAAAT!!! Problem solved!! Lowest oil pressure seen under acceleration: 5.5bar!! 

This device just rocks!!
I'll take pics soon to show you how I have routed oil lines (this was a true hassle!).


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## Chris Wilson (Aug 20, 2001)

Yes, please share, I am fitting an Accusump as belt and braces for my new R26DETT engine, as well as a Tomei pump, head drain / crankcase breather, and a Trust deep sump extension. I have made a T piece to go into the return from the cooler to the block. Was thinking of putting the Accusump canister in the passenger footwell. It's not a road car.


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## nozza1 (Jan 13, 2007)

An update on this please

Found this thread to be a riveting/informative read.

Would like to know, with the extended sump, tomei pump, oil cooler, accusump, would you still fill the sump up to the max mark on the dipstick.

Its because l have heard a theory of the misconseption on oil level on extended sumps and that it should be nearer the minimum mark than the maximum as you increase the chances of oil getting past seals (turbo) as one well known member had discovered.

Thoughts please.


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## Chris Wilson (Aug 20, 2001)

I run an extended sump, Tomei pump and extended pick up to match the sump extension, and still I fill to 2 mm over the full mark on the dipstick. Quite why anyone would think this would affect turbo seals or cause cavitation I can't understand. It works fine, oil pressure is stable and the only corner on UK circuits I'd have any worries about is Gerards at Mallory Park, which is a notorious test of wet sumps due to the G forces and the length of time they go on for. It would doubtless be fine on road tyres, but slicks might be optimistic. If I went there I'd the Accusump I have in the workshop I think


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## northstar34 (Jul 24, 2009)

sounds interresting.


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## nozza1 (Jan 13, 2007)

forgot to mention that is was a high spec RB30, would that have made a difference?


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## Chris Wilson (Aug 20, 2001)

I doubt the oil pump is aware of how much the engine has cost  I just sucks oil from a pickup in the sump. If said pickup is say 3 inches longer it won't throw a wobbler...The turbos won't know if they are draining into a 2.6 or 26 litre capacity engine, they jusy gravity drain into a region above the oil level. If the sump underneath is a mile deep they won't know nor care. As for turbo seals, why should they be affected at all by the sump depth?


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