Rb20det And Rb25det

[Halo a]

Hey there. Im doing sum research about these 2 engines. I want 2 know about these 2 engines differences. I want to know more about internal, block and etc. is the oil flow, water flow different between them ?

Which engine is better handling for 500HP? which engine can survive long in 500HP ?

Thanks for the advice

Mick

Edited March 5, 2007 by Halo a

[Rolls]

A 500hp Rb20 would not be very fun to drive, let alone easy to make. It'd need to be seeing 10k.

Edited March 5, 2007 by Rolls

[nisskid]

RB30, the end.

[Halo a]

ok im very fresh to RB30 i did some research before in google but nothing much is pop up about this engine.

Also, wat is difference about them. Is RB30 strong than RB25 ?

Thanks

[Simon-S14]

try searching

[bubba]

The engine will be as strong as the parts you can afford to put in it.. I think all the RB block are much of a muchness except when it comes to N1 blocks..

P.S. I know of an RB30DETT for sale in Perth if you're interested

[MANWHORE]

man, I don't think you'll get any decent replies to this thread. After people have answered the questino about 2-3 times, their reply gets shorter. After 5 times, it gets shorter again.

In answer to your question. It's simply not worth even trying an rb20 at that level.

[Pauly33GTS-t]

youd think thered be 100 stickied threads by now lol.

[BOOSTA]

Halo,

What car is the RB going into?

Apart from the obvious things like capacity which is

RB20DET - 2 ltr

RB25DET - 2.5 ltr

RB30DET - 3 ltr

There all great engines but like anything else the more capacity you have the easier it can be to make more HP and with more reliability.

But more importantly it will also come down to what components you use and also what gets done to the block and other bolt ons that will make 500hp and make it reliably.

The Rb20det is unfortuately getting alil old and with that fact comes the lower amount of aftermarket parts for it aswell.

The Rb25det is newer and has been gaining in popularity in Australia so the amount of aftermarket parts is quite large which also means cheaper prices aswell.

The Rb30det has been around along time in Australia because of the VL and R31 which where australian made / delivered cars and in large numbers so the aftermarket scene for these is also large and prices vary accordingly.

If you really want to see whats the best my advice would be to visit a few aftermarket workshops who have built a few tough Rb's and just asking them about questions you have. These guys do this for a job and so will have a load of information about whats your best plan of attack for building a 500hp engine with as much reliability as possible.

Maybe even speak with the sponsors from SAU... theres some great workshops who know lots about the nissan engines and could give you rough guesses about easiest options etc... Try searching SAU for specs theres lots of threads about, just make sure u change the search button to 365days so u get all the threads

Try http://nissanskyline.6te.net/ <--- basic info of rb20 and rb25, rb26dett etc etc

Cheers BOOSTA

[Demoniak]

Hey there. Im doing sum research about these 2 engines. I want 2 know about these 2 engines differences. I want to know more about internal, block and etc. is the oil flow, water flow different between them ?

Which engine is better handling for 500HP? which engine can survive long in 500HP ?

Thanks for the advice

Mick

500hp?

no offence but have you just finished playing need for speed?

ive seen some 300-350 kw powered rb26's and not only are they psycho but cost a lot to build.

Unless you are going to sell kidneys on the black market just got for 200-270kw and be done with it.

No engine will "surivive" 500hp.. it all comes down to how much money you got to make the engine bullet proof.. just dont expect that you wont have to rip it apart every month to fix shit up.

also 500hp on a single turbo means the lag would be just too stupid.. unless you put Nos in it ( making it 1000% illegal on roads and a rebuild every 1000km's).

I think you should read more on google first before making a tard post like this

[liamlw]

bbbbbbbbbbbbbbbbbb

Edited July 11, 2007 by liamlw

[Cubes]

500hp (~310rwkw on the dyno I run on) is a walk in the park for stock rb30's and rb25's providing they are in good condition and tuned well with an appropriately sized turbo.

Its wise to drop the static comp to a more friendly 8.5:1 if its an rb25.

The Rb30 will be more reliable than the rb25 as it 'can' do it with less rev's. The same goes for the rb25 vs the rb20.

A gt35r .82 comes makes all its boost a shade over 3500rpm. A GT3040 which can also 'squeeze' 500hp if you push 22psi through it with a set of cams, good exh. manifold, plenum etc will come on strong a shade over 3000rpm. Thats not 'stupid' lag demoniak.

[-_-StRyDeR-_-]

mate just search the forums for your answers, they are here! not google.

[Halo a]

Halo,

What car is the RB going into?

Apart from the obvious things like capacity which is

RB20DET - 2 ltr

RB25DET - 2.5 ltr

RB30DET - 3 ltr

There all great engines but like anything else the more capacity you have the easier it can be to make more HP and with more reliability.

But more importantly it will also come down to what components you use and also what gets done to the block and other bolt ons that will make 500hp and make it reliably.

The Rb20det is unfortuately getting alil old and with that fact comes the lower amount of aftermarket parts for it aswell.

The Rb25det is newer and has been gaining in popularity in Australia so the amount of aftermarket parts is quite large which also means cheaper prices aswell.

The Rb30det has been around along time in Australia because of the VL and R31 which where australian made / delivered cars and in large numbers so the aftermarket scene for these is also large and prices vary accordingly.

If you really want to see whats the best my advice would be to visit a few aftermarket workshops who have built a few tough Rb's and just asking them about questions you have. These guys do this for a job and so will have a load of information about whats your best plan of attack for building a 500hp engine with as much reliability as possible.

Maybe even speak with the sponsors from SAU... theres some great workshops who know lots about the nissan engines and could give you rough guesses about easiest options etc... Try searching SAU for specs theres lots of threads about, just make sure u change the search button to 365days so u get all the threads

Try http://nissanskyline.6te.net/ <--- basic info of rb20 and rb25, rb26dett etc etc

Cheers BOOSTA

thanks boosta. the engine will going into r32 4 door. I do knw a awsome mechanic i will ask him when i back to OZ im asking all these Q's because not much people know about RB's in my country.

I havent bought a r32 yet but i have a s13 project car and RB26DETT is ready to get in. but im thinking r32 4 door should be better balance since is a sedan n a bit heavier. That's what im thinking of building 500 HP engine. Im aiming 250-300 rwkw so that should be around 500 HP in the engine. correct me if wrong.

i will speak to my mechanic and ask him about all of these Q'.

I did some reseach about the RB's engine but end up not much answer pop up. I didnt research enough yet. but thanks for the wedsite. i already go though with that already too.

Thanks

[Roy]

You want to know the strongest RB, well i say its the RB20. Hang with me for a second.

They only have 78mm bores so they have plenty of meat between the cylinders. So the block is very strong.

They also have a very short stroke meaning that for the same rpm they have lower piston speeds. The big end bearings are about the same for all RBs so you have a very similar surface area of bearing for lower loads meaning the bottom end wont be as stressed.

The smaller bore also means smaller and lighter pistons meaning that again the forces from rotational mass is reduced. The rods in the RB20 are very strong std. Throw in some aftermarket rods and it would be near impossible to damage them.

Now the problem with the RB20 is the same small bore means small combustion chamber which means smaller valves then the bigger RBs. But the difference may not be as much as ppl make out. Isolate one cylinder and look at the surface area of inlet and exhaust valve and compare it to the displacement of that cylinder. The ratio may not be as dramatic as ppl make out.

So you can only really go 1mm oversize in the valve department. And the other big problem is the small displacement Rb20 will have a hard time spooling up the turbo required to make 500hp. So the bigger RBs will make the power easier and sooner.

So whilst on paper the RB20 is probably not the motor to use for 500hp...it could very well be the strongest at 500hp.

But that doesnt really matter, because looking at it. 500hp is about 360kws. So in a GTSt thats about 310rwkws. An RB30 or RB26 would do that number in its sleep. Std RB30 bottom ends, and std RB26s will easily make that power with the right turbo.

But getting back to it, if you are building the strongest RB you can. Then i would say the strongest would be an Rb20 with RB26 crank. So the stroke and piston speeds would be no worse then an RB26. Only you would be running a smaller, lighter 80mm piston. The block would still have plenty of meat in it and handle huge cylinder pressures.

So you would end up with a 2.3L motor with a longer stroke then an RB25 helping torque, which the boost in displacement would be helping two fold. The engine would rev easier and harder then any other RB. With a bit of attention to the head it will flow enough to spin a HKS 3037, or Trust T67 required to make 310-320rwkws. And the thing would do it all day every day and be very strong.

But again, a std bottom end RB30 would easily do the same job at lower rpm. Even though i dont think that ultimately the engine would be stronger...at that power you mechanically wont be stressing either motor.

[Halo a]

500hp?

no offence but have you just finished playing need for speed?

ive seen some 300-350 kw powered rb26's and not only are they psycho but cost a lot to build.

Unless you are going to sell kidneys on the black market just got for 200-270kw and be done with it.

No engine will "surivive" 500hp.. it all comes down to how much money you got to make the engine bullet proof.. just dont expect that you wont have to rip it apart every month to fix shit up.

also 500hp on a single turbo means the lag would be just too stupid.. unless you put Nos in it ( making it 1000% illegal on roads and a rebuild every 1000km's).

I think you should read more on google first before making a tard post like this

Yes i already finished playing need for speed carbon while back. but im not stupid until sell my kidneys n spend on my car.

i will find out every single detail and ask the Q' in this thread !

[Cubes]

I'm with Roy. Sort of.

I remember an old Zoom article on the Gibson GTR. At Bathurst Gibson motorsport limited rev's to 7000rpm as over 7000rpm the life of the motor reduced drastically.

So maybe a high reving RB is not such a good thing?

The other option is to shove a heap more boost in to the 2ltr so that it doesn't have to rev as hard to make the same power. But then you narrow up the power band and place a greater reliance on nice fuel.

[Halo a]

500hp (~310rwkw on the dyno I run on) is a walk in the park for stock rb30's and rb25's providing they are in good condition and tuned well with an appropriately sized turbo.

Its wise to drop the static comp to a more friendly 8.5:1 if its an rb25.

The Rb30 will be more reliable than the rb25 as it 'can' do it with less rev's. The same goes for the rb25 vs the rb20.

A gt35r .82 comes makes all its boost a shade over 3500rpm. A GT3040 which can also 'squeeze' 500hp if you push 22psi through it with a set of cams, good exh. manifold, plenum etc will come on strong a shade over 3000rpm. Thats not 'stupid' lag demoniak.

hey cubes thanks for the information. I havent finish go though with the RB30/25/26 yet. That's why im posting this thread. i want to know which engine is more reliable. i read on magazine said RB30 bottom end and RB26 is more staight forward. Im also still fresh in RB30 but i will find out the answer. also wat ecu have to use wat turbo and in safe boost level.

Thanks Cubes

[Halo a]

You want to know the strongest RB, well i say its the RB20. Hang with me for a second.

They only have 78mm bores so they have plenty of meat between the cylinders. So the block is very strong.

They also have a very short stroke meaning that for the same rpm they have lower piston speeds. The big end bearings are about the same for all RBs so you have a very similar surface area of bearing for lower loads meaning the bottom end wont be as stressed.

The smaller bore also means smaller and lighter pistons meaning that again the forces from rotational mass is reduced. The rods in the RB20 are very strong std. Throw in some aftermarket rods and it would be near impossible to damage them.

Now the problem with the RB20 is the same small bore means small combustion chamber which means smaller valves then the bigger RBs. But the difference may not be as much as ppl make out. Isolate one cylinder and look at the surface area of inlet and exhaust valve and compare it to the displacement of that cylinder. The ratio may not be as dramatic as ppl make out.

So you can only really go 1mm oversize in the valve department. And the other big problem is the small displacement Rb20 will have a hard time spooling up the turbo required to make 500hp. So the bigger RBs will make the power easier and sooner.

So whilst on paper the RB20 is probably not the motor to use for 500hp...it could very well be the strongest at 500hp.

But that doesnt really matter, because looking at it. 500hp is about 360kws. So in a GTSt thats about 310rwkws. An RB30 or RB26 would do that number in its sleep. Std RB30 bottom ends, and std RB26s will easily make that power with the right turbo.

But getting back to it, if you are building the strongest RB you can. Then i would say the strongest would be an Rb20 with RB26 crank. So the stroke and piston speeds would be no worse then an RB26. Only you would be running a smaller, lighter 80mm piston. The block would still have plenty of meat in it and handle huge cylinder pressures.

So you would end up with a 2.3L motor with a longer stroke then an RB25 helping torque, which the boost in displacement would be helping two fold. The engine would rev easier and harder then any other RB. With a bit of attention to the head it will flow enough to spin a HKS 3037, or Trust T67 required to make 310-320rwkws. And the thing would do it all day every day and be very strong.

But again, a std bottom end RB30 would easily do the same job at lower rpm. Even though i dont think that ultimately the engine would be stronger...at that power you mechanically wont be stressing either motor.

Thanks Roy im getting the idea a bit but i still have to do more research. When i start do this engine rebuiling i will post up here and get more opinions.

Thanks heaps Roy n Cubes

[Roy]

I'm with Roy. Sort of.

I remember an old Zoom article on the Gibson GTR. At Bathurst Gibson motorsport limited rev's to 7000rpm as over 7000rpm the life of the motor reduced drastically.

So maybe a high reving RB is not such a good thing?

The other option is to shove a heap more boost in to the 2ltr so that it doesn't have to rev as hard to make the same power. But then you narrow up the power band and place a greater reliance on nice fuel.

LOL...i know a guy with several Gibson RB20s, and they didnt limit them to 7,000rpm at Bathurst

Anyway, we will soon know how long a std RB20 can make 450hp for