Rb26 Or Rb 30

[Lithium]

I know of them from marvelling at Arab drag/sand racing patrols over the years but not so sure they'd drop straight into an engine bay designed for an RB-series engine. An RB30 is not a completely different family of engine by any stretch.

[Lived4eva]

It all comes down to intended purpose. It seems people want to say outright that an RB30 bottom end is better no disadvantages. While in certain circumstances this might be true. It is definitely not true in all.

Weighed up going RB30 for my R32 GTR streeter and found that it would probably be a fair bit of mucking around plus legality, insurance and resale. Now had it been for a circuit or drag car I would of been more than happen to whack the RB30 bottom end in.

Truth is time and time again the RB26 has proven it can produce big numbers. I can't realistically say I need more than what an RB26 can produce for a street driven car. I know having the 3litre bottom end would have made me feel a bit bigger in the pants but at the end of the day it would have made no difference to what I was using the car for.

[NZM.031]

and having owned an r31 with the rb30e... while it wasnt twin cam... it had head work and a large cam so it had a few more rpms up top... i also thought it would be a great idea to chuck in some 4.11 diff gears the out of a pintara instead of the 3.7s in the skyline.

now correct me if im wrong... but dont all our skylines have 4.11 gears??? which work great with the lesser capacity engines.. giving them a bit more acceleration/torque through the gears alone..

after i put the 4.11s in... i was constantly changing gears... 1st gear was non existent, it would reach redline within a second after launching... 2nd gear was over and all i was doing was 80km.. it was harsh on the driveline aswell as the engine. i changed the gears straight away and enjoyed revving it out with some time in between shifts.

[N1GTR]

Wait on, has anyone tried the patrol motor in a GTR?

Does the 26 head go straight on?

Mmmmm that sort of displacement would be great........with a t04z

[Angus Smart]

That patrol is a 3.4 diesel yeah? it would surely go nicely if a head would fit on it!!

i'm starting to wish i went with a 3L build.. but i'm sure the 2.6 will still do its intended job quiet well!

[superjet760]

For all the people that arnt interested in making " BIG " power you should pull your rb26 out and put an rb20 in for fuel economy.

Lets face it if your building a forged rb engine your doing it to make power right?

So if this is the case you cant go past the 30/26 MONSTER

[Lithium]

That patrol is a 3.4 diesel yeah? it would surely go nicely if a head would fit on it!!

Pretty sure the motor in question is the TB48DE which is a twin cam injected petrol 4.8litre straight 6 complete with VTC (like RB25DETs). They don't rev particularly hard but are strong as hell and at the end of the day a huge motor so torque and power are going to come naturally. They are a 99.5mm bore, I doubt very very much anything RBish will suit them - I'd expect new mounts would need to be made up and they'd generally pack out an RB-intended engine bay easily, not sure what you'd use for transmission.

There is a little aftermarket support out there too, lots of >700hp ones running around in the Arab nations so there is bound to be information on them somewhere. Have a nosy here: http://www.briancrower.com/makes/nissan/tb48.shtml

[T04GTR]

the only thing that stopped me was fear of breaking the oil pump.... thats it. nothing else.

[N1GTR]

Dave, thats good to hear

[FineLine]

Pretty sure the motor in question is the TB48DE which is a twin cam injected petrol 4.8litre straight 6 complete with VTC (like RB25DETs). They don't rev particularly hard but are strong as hell and at the end of the day a huge motor so torque and power are going to come naturally. They are a 99.5mm bore, I doubt very very much anything RBish will suit them - I'd expect new mounts would need to be made up and they'd generally pack out an RB-intended engine bay easily, not sure what you'd use for transmission.

There is a little aftermarket support out there too, lots of >700hp ones running around in the Arab nations so there is bound to be information on them somewhere. Have a nosy here: http://www.briancrower.com/makes/nissan/tb48.shtml

Yes it is the TB 4.8 litre.Try 1000 to 1200 hp in the land of sand.

Crower makes a neat stroker kit for them too. 5.1 litres to be excact. The peeps talkin dirty thirtys because they want torque could do a lot worse than have a look at one. Over all engine size is not much bigger than an rb. As soon as it cools down enough I am going to measure mine for engine height width etc. The Patrol gearbox,s are already designed to take stupendous amounts of low range torque so they can handle a fair bit. Always the option of upgrading to ppg etc as well.

At first glance the head looks straight from a neo 25. No doubt that isnt the case as I'm sure bolt patterns are different between the 2 engines but i am just as sure that the design has been lifted from the neo.

[Dynamix]

the only thing that stopped me was fear of breaking the oil pump.... thats it. nothing else.

Why not run an external oil pump bud, problem solved. Not matter what series RB motor I'd feel alot safer running that over the normal style pumps.

Back to the 26 v 30, as others have stated I think it all comes down the the purpose intended. In almost all apilcations both can be made to work as well as each other, as there's more than one way to skin a cat. It all depends on your budget, your mechanic and purpose inteded. There is so many other factors that can also influence a decisions, high revs kill/wear motors out quicker, so an rb30 that can make power at 7500 rpm would be better suited than a rb26 that needs to rev to 9000 to make the same amount? But on the other end of scale the extra torque an rb30 can make can kill gear box's, drive shafts and diff's quicker with the extra/earlier torque that can be made.

I see alot of poeple arguring that there mates uncles sisters neighbours cousins dog raced an vl with x combination vs a gtr with x combination motor, which really in the end means nothing. The only way I can see a real world test example of which one can make more power, response, torque, drivabilty accuratly is having either two identicle setups with one being a 2.6L bottom end and the other being a 3.0L or dynoing/racing an rb26 and swapping out the bottom end with an rb30 and dynoing/racing changing nothing at all and tuning to the same perameteres. That would be the fairest comparison (some might say the cam secltions would make a bit of difference being suited to the turbo selction), so untill that happens, all you can do at the end of the say is take as much imformation in, ask to go for rides and ' feel ' what both have to offer, work out a budget, find a tuner that can do what you want and enjoy what you get..

[Lithium]

ask to go for rides and ' feel ' what both have to offer, work out a budget, find a tuner that can do what you want and enjoy what you get..

This should at least give an idea - exact same car, dyno etc. Went in to RIPS as a typical R34 GTR with all the normal bolt ons done to it, came out as an RB30DET with a T04Z. Sure the new engine is running a bigger turbo and more boost etc, but everyone here knows that if it were still a 2.6 the power would start climbing far far later. I'm sure there was another plot somewhere of an RB26 with twin T67s that ended up becoming a 3litre, I might be wrong though.

Boltons RB26DETT (stock R34 BB turbos) vs RB30DET T04Z otherwise same car:

[joeleo87]

Why not run an external oil pump bud, problem solved. Not matter what series RB motor I'd feel alot safer running that over the normal style pumps.

problem with that being the price... the price being half my rebuild budget :S

[Dynamix]

problem with that being the price... the price being half my rebuild budget :S

That was directed at T04GTR btw...

Joeleo87, oiling is the biggest problem on the rb series motors, so I'd address that pretty seriously. I think you'll find with the yen vs aud atm that it will be a fraction cheaper going external over a tomei pump. Not sure on the prices of Jun/Greddy or the others, but whatever option you end up going its going to hurt the wallet, unless you chose the N1 + pro engines collar but personaly i'd be staying right away from the n1 pumps. As said by Dirt and RIPS it dosnt matter what motor the oil pump is on if you still rev the tits off it its going to decrease everythings life, balance everything and you'll have less issues, by the best parts you can afford and you'll have less issues and so on.. Have you though about getting a ribs stock internal rb30 bottem end, the value is excellent and pretty cheap considdering how far you can push them.

[joeleo87]

That was directed at T04GTR btw...

Joeleo87, oiling is the biggest problem on the rb series motors, so I'd address that pretty seriously. I think you'll find with the yen vs aud atm that it will be a fraction cheaper going external over a tomei pump. Not sure on the prices of Jun/Greddy or the others, but whatever option you end up going its going to hurt the wallet, unless you chose the N1 + pro engines collar but personaly i'd be staying right away from the n1 pumps. As said by Dirt and RIPS it dosnt matter what motor the oil pump is on if you still rev the tits off it its going to decrease everythings life, balance everything and you'll have less issues, by the best parts you can afford and you'll have less issues and so on.. Have you though about getting a ribs stock internal rb30 bottem end, the value is excellent and pretty cheap considdering how far you can push them.

I hear ya man... after ive replaced my G/box and Diff ill be looking into that oilling issue. As my rear turbo blew only 3 months ago ie. More boost, Rev limiting..... my oil pump will be on its way out shortly. hopefully i can replace the pump before my pump fails and bungs a bearing :S

If im to replace the pump i may as well rebuild the motor to last another 100 thousand KMs.

[N1GTR]

So, just dont bounce it off the limiter if you know its an issue

[Dynamix]

Exatcly.. or build it tough enough to take it. But remember you are doing this to a stock internal rb26dett with about 1/3rd more power than facotry, its days are going to be numbered ever quicker with a rev limitng driving style..

All depends how much power you'e chaising too, preped stock rods, forged pistons, acl bearings, greedy oil pump (either r33 crank or collar the r32 crank) balance every part in the rotating mass, get someone who's good at bolting it all together and you have a 400kw motor no problems. No as dear as some would make out to be and 400kw is nothing to sneeze at..

[T04GTR]

yes. but 3.5 years ago when i built my motor, i wasnt thinking of that.. if im gonna do an external pump it gonna be a propper dry sump set up..

but now days i can make a pretty good wet sump. anyone got a s2 rb30 block etc etc??????? (with the factory idler hole tapped)

[T04GTR]

hey ive got till the end of 2010 till im licenced

[N1GTR]

Dave ive got a couple of motors spare.

You've got ages until you can drive it again anyway