Rb24

[nisskid]

yes i know there are other rb24 threads out there, i've read them, none really seem to answer my question however. I'm not an engine man, as ull come to find out, but i know one thing, i love the sound, revability and reliability of my rb20. i'm not looking for huge power figures, but some more power would be nice. I dont want to be like everyone else as put a 25,26,30 in, doesnt interest me. the RB22/24 does however and i came across an opp to buy one in a car already built. It's a Tomei kit, so forged pistons and GTR crank. i guess my worry is, that the 24 will basically just be a 25, but really unreliable.

looking at the bore and stroke differences it makes me think, being someone chasing a nice revvy engine, am i taking a step back going with the 24? will going less over-square make it less rev happy than the 25/26/30, especially with the smaller head of the 20?

if so is it worth me still picking up this nice little package, but maybe replace the long GTR crank with a 25 or 20 one, go back to the shorter stroke, but keep all the goodies that came with it and sell the GTR crank for some nice $$$?

i dont mind building a little 20, but when this came a long, it just seemed to perfect to pass up, most of what i read into rb24's was that they were just to expensive for what u were getting, i guess im asking u guys, if u took the cost aspect out, would u go a internally modified rb24 over a stock 25 or 30 if u were chasing a bullet proof rev happy engine?

[Roy]

RB24 has the same stroke as an RB26, only runs a smaller, lighter piston. So with less inertia you would expect the thing to spin nicely to big revs if all is balanced and tuned well.

If you have the Tomei pistons then you cannot go back to the RB20 or 25 crank as they are designed to work with GTR rods and crank re deck height etc. Change the crank and rods and you will end up with a strange compression ratio.

If you have a well put together RB24 just throw it in. The whole rev happy etc has a lot to do with tuning, bolts on ie turbo. A 2530 isnt going to do a lot. Something like a 2835/3071/TD06-25G/T67 is going to provide enough airflow that it will happily spin to 8,000rpm and rev out nice and quick.

LOL, one day i will find out when i put all the Tomei gear i have under the couch into an RB20

[nisskid]

it's got a TD07-25G on there apparently, dunno if i could be bothered changing it.

[Russman]

So RB24's are just a GTR crank in a RB20? Were they made by nissan or just a aftermarket thing?

[R31Nismoid]

Aftermarket russ. You can make 2.1, 2.3, 2.4 depending on what parts you want to use.

[NZM.031]

RB22 = 82mm pistons (4agze, tomei or custom)

RB23 = 82mm pistons, RB25 crank and rods

RB24 = 82mm pistons, RB26 crank and rods

Ben Ellis built one up for the HPI project R32... the engine build started in issue 44 (it has an orange background on the cover) i think.. the RB24 used Tomei pistons and head gasket, RB26 Rods, R33 GTR crank, and lots of machining

the tops of the rods need a bump to be removed and the block needs to semi circles machined in each cylinder for the big end to clear, the crank, rods, and pistons need to be all balanced together.

the bores needed to be opened to 82mm with tomei pistons or 4agze pistons.

the rb20 has shitloads of material in the block so it wont be any weaker... but its worth getting your block checked over.

i cant remember if the combustion chambers in the head need to be opened up a little to fit the new bore size.

the people that say it isnt worth it are mainly the RB20 haters.. why do all that engine work when you can drop in an rb25 or rb26 for the same money?? coz you have a brand new, rev happy engine, with more low down torque to spool up a bigger turbo and still rev out... thats why!

building an rb24 in reality is no more expensive than rebuilding any other performance engine.. the machine work is all done by cnc machines, so it doesnt matter whether its boring it for 2 thour oversized pistons or 82mm pistons.

im thinking about building my rb20 to an rb24... but it does cost alot.. but it will be worth it.. its different but its been done before.

nisskid... go for it.. you know you want to!!

[bcozican]

im getting rb23 (25crank 26 rods) built right now for the exact positive reasons mention... rather than going the throw in a rb25 std thing

for a little less capacity etc im getting a brand spanking new forged engine with more torque than the std rb20 i was pretty happy with anyway and will rev its nuts off rather than throwing in a 100K old rb25

especially if its done for you and all in good nick at right price theoretically you'd have a better package than a std rb25 stuff

Edited January 8, 2010 by bcozican

[Russman]

Anyone done a 24 here? What's the approx cost for parts? and labour?

[R31Nismoid]

theoretically you'd have a better package than a std rb25 stuff

Except for the fact you have a head that (roughly) flows 30% less.

So you are needing to screw boost in like a champion, and rev it's ass off to get it to do the same thing a RB25 could do with far less stress - which is equal to overall life.

There are pro's and con's for each argument.

[NZM.031]

Anyone done a 24 here? What's the approx cost for parts? and labour?

Rocco's Performance did the hpi one... they might be the best to speak to.

2nd hand 26 rods and crank are easily sourced.. you can use 25 rods if you want to be cheap... they are the same as rb26 but 26 are betterer.

you can use r32 rb26 crank, but r33 is betterer.. then you can run the r33 oil pump.

the pistons are readily available through tomei, nengun do them for around $1700 for a piston kit..

tomei head gasket for 83.5mm bore in 1mm, 1.2mm and 1.5mm is around $350 from nengun..

block prep and balancing i have no idea of.. that is my next research point.

*i am in no way affiliated with Roccos, i just know thats who did the project r32 one*

[_Ryan_]

and you need a GT30 size turbo to match... great for a street car if you get pulled over... Then out comes the motor. cost of ownership just went up.

A near stock Rb26 engineered will do the same job, legally.

[bcozican]

Except for the fact you have a head that (roughly) flows 30% less.

So you are needing to screw boost in like a champion, and rev it's ass off to get it to do the same thing a RB25 could do with far less stress - which is equal to overall life.

There are pro's and con's for each argument.

yeah i totally agree, for me .. i blew my engine but still have all supporting bits cams injectors ecu etc etc to go on and not looking for super mega hp so getting one built and having little things done to help oil flow etc etc

so rather than have to sell most stuff off first then do the swap it suited me

head getting ported n polished etc in build so should help a bit does anyone know the mmcf friggin lcympv things flow rating of the std rb 20 and rb 25 heads??

[Russman]

Rocco's Performance did the hpi one... they might be the best to speak to.

2nd hand 26 rods and crank are easily sourced.. you can use 25 rods if you want to be cheap... they are the same as rb26 but 26 are betterer.

you can use r32 rb26 crank, but r33 is betterer.. then you can run the r33 oil pump.

the pistons are readily available through tomei, nengun do them for around $1700 for a piston kit..

tomei head gasket for 83.5mm bore in 1mm, 1.2mm and 1.5mm is around $350 from nengun..

block prep and balancing i have no idea of.. that is my next research point.

*i am in no way affiliated with Roccos, i just know thats who did the project r32 one*

$$wise I'll prob just follow the hoards and shoot for 300kw with 25 and standard internals when I want more power.

[NZM.031]

A near stock Rb26 engineered will do the same job, legally.

like i said.... RB20 haters... what part of making an RB24 is illegal??? its all neatly contained in what looks like a standard rb20.

removing and transplanting engines takes the spirit out of the car.. rb25's are boring.. they are the middle child.. i would rather spend $20000 on my RB20 and make whatever power it makes than put an rb25 in my r32.

a stock rb26 would tromp the rb20... no shit... but the rb26 belongs in the GTR... like the harbour bridge and bondi beach belong in sydney.

[R31Nismoid]

but the rb26 belongs in the GTR... like the harbour bridge and bondi beach belong in sydney.

I guess at least i can say i've heard more ridiculous statements...

[joeyjoejoejuniorshabadoo]

i would rather spend $20000 on my RB20 and make whatever power it makes than put an rb25 in my r32.

and you have somehow managed to take the rb20/r32 fanboi shit to a whole new level of wank...

[DRD-00F]

An RB26 belongs in everything! I'd put on on a go kart if I could...

[NZM.031]

and you have somehow managed to take the rb20/r32 fanboi shit to a whole new level of wank...

ill take that as a compliment.

why are people so scared of engine work??? atmo and v8 guys thrive on calculations and mixing and matching this with that to get this. everything gets stroked and ported and balanced

turbo guys just wanna push the stock bottom end as far as it can go, if the stock bottom lets go, they put in another one.

rb26 has nothing on 2jz anyway... id be putting one of them in a go kart.

[D-limo]

RB20 head can't be that bad, my cefiro arrived with a rb20 head, east bear 1.8mm HG on a rb25 bottom end.. Was good enough to compete in the advan drift meeting.. Theres an r32 about in japan built by garage testorossa (sp) with an rb20 head on 30 bottom end.

Hands down would take a 24 if it had enough research and $$$ are behind it.

[Russman]

why are people so scared of engine work??? atmo and v8 guys thrive on calculations and mixing and matching this with that to get this. everything gets stroked and ported and balanced

Only money and knowledge. RB25 is cheap and been done to death.

That being said I would have more respect for an RB24 setup.