R33 Rb30 Conversion

[Cubes]

Thanx for digging that up SteveL.

I was in denile, now I've accepted it

Those figures u posted are spot on as the measuring tool showed only ever so slightly under 11mm. This thread is turning out to contain some quite detailed interesting information.

[the phantom]

Hey,

I can also confirm the measurements. I used a pair of verniers and got 10.8 mm wide for the RB30E and 11 mm for the RB25DET. Both gears have the same internal diameters differing only in engagement width onto their respective crankshafts.

So it looks as though the RB30ET pump is the way to go, dont think the over-revving will be an issue for us !

[GiJOr33]

so the RB25DET oil pump isn't as good as the RB30ET pump??? i wouldn't have thought that as it also has to power oil squirters and VCT in the head... as well as the turbo supply.

[the phantom]

Without actually seeing an RB30ET pump I can only speculate....damn I wish I had one lying around. Even though it appears the 'ET pump has a wider gear than the '25DET , I dont believe you can automatically assume the '30ET flows more than the '25DET. There is the substantial difference in tooth design to consider (see the pics I took above), so the '25DET may actually be more efficient and flow more then the 'ET even with the thinner gear. Given the information we have, one would think this is the case for the exact reasons you mentioned above, i.e double overhead cams and oil squirters vs single cam and no squirters for the '30. Personally I'm not too fussed about the crank engagement issue too much as my application is for a strong street engine with revs way below astronomical. What does concern me though is the flow capability of the 'ET pump and the effects to the long term health of the engine. At the moment I'm more inclined to fit the early RB26DETT pump, or modify the crank and fit the '25DET pump and take advantage of the R&D Nissan has already done. I know the '30ET pump works in my current engine, but I neither have the time nor inclination for regular rebuilds, or to investigate the long term effects. I preffer to do things right the first time and build for long term trouble free use.

[riceline]

Hey Guys

I have got a R31 rebuilt/balanced rb30 botom end with a R32 rb25de head. I am having troubles with the loom and the injectors... So far I have soldered the plugs from the top feed R32 injectors onto the R33 wireing loom... This works a little (dont think that they are all on positive to positive, so I am trying to find a wireing diagram to figure that bit out).. but not the best at all (don't think they are all fireing properly). Any help with this would be great. But if thats not possible.

Is there any way to get the r33 rb25det injectors (side feed) to work on the R32 Rb25de manifold.

I guess im just after some sort of how to as to what to do to get it working.

This is all that is stoping me from going now..

Thanks

[Sydneykid]

Hi Ghost Who Walks, I think the issue with comparing RB30 (SOHC) oil pumps with those from RB20/25/26 (DOHC) is rpm. The RB20/25/26 oil pump is obviously designed for far greater engine revs (8,500 rpm) than the RB30 pump (6,250 rpm) would ever be. So I would always use an RB20/25/26 oil pump. Which one depends on your power target and budget.

Hi riceline, stick with the top feed injectors, you have a much greater choice at far lower prices than side feed injectors.

Hope that helps

[the phantom]

Hi Sydneykid,

Yeah that certainly adds up. Although my current engine seems to have held up OK for over 55K km with the ET pump, it is only relatively mild (250 rwKW) but has had more than its fair share of excursions to the firm RPM limit of 7000. Who knows how close to the edge it has come. With the new one in progress I intend on much more ( I'm not scared yet !) , and with my intention to dabble in drag racing and its associated stresses, I'd rather not take any chances and skimp here. How does one reliably modify the RB30 crank snout for the wider gear? I'm thinking some sort of keyed shrink fit adaptor on a turned down crank snout. Any recommendations or experiences on how to do this? I do recall adaptors being available for the early RB26's from some Jap company....

Sorry Joel, I fear a relapse in your denial condition

[Cubes]

Phantom,

I am concerned..

I seriously have run out of money for a new pump, I can afford a second hand pump but not new. I havn't been able to track down a second hand turbo pump however I have tracked down a second hand RB25DE NA pump for $100.

I'm thinking I may be able to use a RB20DET valve pressure reg in the RB25DE pump.

Can any one help me out or has the resources to find out if the RB25DE pump is suitable for turbo application If the RB20DET vavle pressure reg is used?

[Sydneykid]

Hi guys, we have used a Jun late RB26 oil pump on an RB30 using the Jun adaptor. It's just a ring that fits between the crank (small) and the oil pump (large). I ordered it from Nengun with the pump so I don't know how much it cost, but it wasn't much.

You may already know this, but just in case. Changing the pressure relief spring doesn't increase the amount of oil flow, it just increases the maximum oil pressure. Pressure is not the problem, it is the amount of oil flow that I consider important. This means any N1 designated pump is pretty much a waste of time as it only has a stronger spring. The alternative is an aftermarket (brand name oil pump) and the prices of those are simple ridiculous. I could buy a dry sump pump for less.

I keep hearing about RB's with block mounted oil squirters needing more oil pressure and flow than RB's with big end bearing (conrod) supplied oil squirters. I don't believe there is any difference, the amount of oil supplied is pretty much the same, as would be the pressure required.

Bottom line, I used an RB26 oil pump with new, slightly stronger pressure relief spring, cost $5 from the local spring supplier. I had the choice between the RB30 oil pump (that came with the RB30 block) and the RB26 oil pump (that came with the damaged RB26). I strongly suggest you check around, plenty of guys with GTR's are upgrading the their pumps and sell off their perfectly good, standard RB26 ones cheap.

Hope that helps

[GTR-Ben]

So does the stock RB26 oil pump from an R32 bolt up to the stock RB30 or not?

I have a spare R32 GTR pump, don't know if it would be worth sending to you though joel, i'm sure you can find one there cheap enough.

[the phantom]

Hi Sydneykid,

But the RB25/26 has piston oil squirters AND conrod squirters, wheras the RB30 only has the conrod squirters. I was under the impression that the conrod squirters lube the cylinder walls and the piston squirters cool the piston from below. Wouldn't having both together require additional flow? Do you run the piston squirters on your RB31's?

[Cubes]

RB20t pump was measured up today.

Didn't get the teeth counted however will do it tomorrow.

The gear width is 9mm.

Piston squirters are good to have however they are not detrimental to a 450-500hp engine. I look at it as there have been that many hi-po VL turbo's getting around that with a set of forged pistons without failures so it won't matter a great deal. If I was doing the whole hog (rods etc) I would most definately adapt the oil squirters.

Its easy to do, should have done it but to be honest I didn't really want to fiddle to much.

The piston oil squirters is most probably why the RB25DET's hold so much power (250rwkw+) with a good tune for so long.

[Sydneykid]

Holla GTR-Ben, the early RB26 oil pump drive is the same as the RB20 and the RB30. So the early RB26 oil pump, will fit the RB30 crank.

Hi Mr Walker, sometimes we use block fed oil squirters in RB31's, sometimes we don't, it all depends on what type of conrod we use. Provided the oil flow from the big end is correctly directed and there is sufficient flow, it doesn't seem to make any difference. We ceramic coat the tops of the pistons, as that works better than oil squirters. It contains the temperature within the combustion chamber. So not only do you get cooler running, you also get more horsepower, which does not happen when you use excessive oil to cool the piston. This is because the extra combustion temperature is passed into the oil. Plus, the oil flowing upwards underneath the piston slows the motion of he piston down, and thus absorbs horsepower.

Sup Joel. It is not easy to get oil squirters into an RB30 block. The main bearing oil gallery is in a different position to those in an RB20/25/26. So there is considerable machining required to make them fit.

Hope that answers all the questions fellas

[riceline]

hmmm - so sick of my r33 rb30det!

The botom end has been completly rebuilt - Balanced everything - honed - cleaned etc etc.

R32 Rb25de non vct head is on. Using the smaller na injectors..

just can't get the prick of a thing to run properly!(3months without a car sucks!)

Does anybody know who in QLD is good with the rb30det's?

I'm at the point of just sending it to them.

I have heard good and bad about Sub Zero anywhere else that can be recomended?

[matlowth]

Riceline -what's the prob with your car?

Cheers,

matt

[Cubes]

riceline,

Can you grab the part number off the cam belt for me?

Did u use the tensioner above the waterpump setup?

The bloke fitting has fitted the head on the block however the cam belt number according to his supplier isn't available?!?!?!

with regards to your problem.

You have an R33.

You have used a Non-VCT head? Why?

You are using smaller injectors? Why?

The best way is to keep things simple.

If you have an R33 use the top end from the R33 RB25DE/T.

If you have an R32 use the top end from the R32 RB25DE.

[Bobjones]

riceline,

 

with regards to your problem.

 

You have an R33.

You have used a Non-VCT head? Why?

You are using smaller injectors? Why?

 

The best way is to keep things simple.

 

If you have an R33 use the top end from the R33 RB25DE/T.

If you have an R32 use the top end from the R32 RB25DE.

Could not agree more...

the fact is the VCT head works well as it contributes greatly to low down and mid range torque...it also slow alot better so that you can USE the increase capacity of the bottom end...

Obviously you have done your homework and investment re the bottom end, maybe a similar investment in the head is warranted!!!

The second is your better off using the head combined with a decent ecu...what are you running???

Also running the standard na injectors is just silly (no offense) but they flow bugger all...

[Cubes]

If you use the RB25DE NA injectors it is the same as using the RB20DET injectors.

They both flow 270cc's.

With a bit more fuel pressure the 270cc's have managed around 220-240rwkw.

When pushing injectors to the limit you also have to be aware that you alter their spray pattern. In turn if they are spraying while the inlet valves are open (duty cycle maxed) it is possible to spray on to the exhaust valve which can damage the exhaust valve.

Similiar to pooring boiling hot water in to a glass.

Generally this is one of the biggest problems with diesels when their injectors fail.

Well thats what my engine builder told me. I don't really know.

RB30DET guide has been updated.

I've gone right through it and fixed up a few things..

I've also added a few little things i.e heater hose attachments etc.

Timing belt tension issues (over 20kg's) when only using a tensioner above the water pump. Requries a tensioner also on the torque side of the belt (near crank).

The problem we had was we didn't have enough loosening adjustment as the tensioner would foul the timing belt cover. Using the RB style tensioner isn't a problem on the torque side as it is a locking type tensioner. Not a spring loaded type for example the spring loaded type tensioner on a VN V6 Fan/waterpump/AC belt.

Nissans recommended spec for the timing belt tension is 20kg's.

[matlowth]

The same sort of thing also applies to "high-flowed" injectors... It stuffs up the spray patterns....

Cheers,

matt

When pushing injectors to the limit you also have to be aware that you alter their spray pattern. In turn if they are spraying while the inlet valves are open (duty cycle maxed) it is possible to spray on to the exhaust valve which can damage the exhaust valve.

Similiar to pooring boiling hot water in to a glass.

[Sydneykid]

Hi Joel the maxed duty cycle spray on the exhaust valve is only relevant at low rpm (2,000 or less) so it really is diesel problem only. Unles you could get an RB to amx out the injectors at idle, some engine huh?

Hi Joel (thanks for quoting me on which head to use in which chassis) and BobJones, I have used a RB30 bottom end with a RB25DE top end. The first one I ever buiit, it is still going 5 years later and making 500 bhp. So leave riceline alone, if you are doing it on a budget and want to sell a complete RB25DET, it's a perfectly acceptable solution.

As for VVT being worth it, maybe on an R34 GTT where it is infinitely variable but on an R33 GTST where it is either on or off, very marginal. If I got it for free I'd keep it, but if I have to pay $1,000 more for it, not gunna happen. Plus I can get heaps of used cams for a non vvt engine.

Hi matlowth, I have tried quite a few injectors at over standard pressure, I have yet to find one that has any problem at +15%. So I can comfortably say increasing the flow by 10% is a pretty safe option.

Hi riceline, I don't think you need an RB specialist, you are not looking at tuning it, just diagnosing what's wrong. This is standard mechanics stuff, any good workshop should be able to do it, all they need is a leak down tester, a multimeter, a timing light and a mechanics stethoscope. A quick leak down test will tell them if everything is OK inside the engine and if the valve timing is close enough. Then it is spark and fuel. Do all 6 plugs fire when they should, that's timing light stuff. Do all 6 injectors fire when they should, that's multimeter and stethoscope stuff. Find your local workshop with that gear and I’ll bet they can diagnose the problem.

Hope that helps