Jump to content
SAU Community

Recommended Posts

I was reading the new HPI mag and read something about building a 2.4 ltr RB20, it said you use a gtr crank and rods with 4AGZE pistons.

Anyone built/heard of one locally. For the price of a stuffed rb20 it would be as cheap as buying a rb25 probably with something a little different.

Link to comment
https://www.sau.com.au/forums/topic/8478-rb24/
Share on other sites

  • Replies 45
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

ok I have heard of

rb 2.2, = tomei larger pistons only

2.3 bigger pistons 81-81 mm with rb25 crank and rods

2.4 with the tomei pistons and rb26 crank and rods there is machinig requiered but not sure what

2.45 special hks cranks rods etc and dispalyed on my site

do a search on the sdu foums it has been disussed heaps personally I would only do the tomei pistons or copies 82 mm cause I know some one who made around 600 with this combo.

and decided againt the 2.4 kit cause and rb 25/26 was chaeper this was in japan

meggala

Link to comment
https://www.sau.com.au/forums/topic/8478-rb24/#findComment-123615
Share on other sites

Guest Works Auto

Guys im in the process of building a RB24 for my 32 as yet ive only got the 26 crank and rods havent yet sussed out what im gonna do for pistolas but my mechanic says he has it sorted so we will just have to wait an see what goes.

Im nearly finnished my upright manifolds for the twin TBO's and the 100mm bar n plate core going into my standard GTR cooler along with the custom plenum with 76mm throtle body, GTR injectors, after market rail and GTR pump it should go a bit better than a standard RB20.

Ill post reports and pics as they are available.

Cheers

Ross

Link to comment
https://www.sau.com.au/forums/topic/8478-rb24/#findComment-123761
Share on other sites

Guest Works Auto

Im sure you have heard of ND4SPD well he is a mate and he is doing the mechanical work as for compression well im an office jockey/salesman so id have to ask him about that so ill let u know.He also seems to think the RB20 pistolas wil fit with the 26rods and crank,.....Cant see it myself but he is the mechanic so i guess he would have a better idea than me. We got a few RB20 blocks and shit around so we will dummy together one before we do it to make sure.

Link to comment
https://www.sau.com.au/forums/topic/8478-rb24/#findComment-123788
Share on other sites

Yeah I heard of him, didn't know he built engines. I would agree with Meggala, that to get the increase in displacement that your after you will need bigger pistons. Luckily the RB20 blocks are relatively cheap so you can do some experimenting.

See'ya:burnout:

Link to comment
https://www.sau.com.au/forums/topic/8478-rb24/#findComment-123804
Share on other sites

The main disadvantage, as I see it is the RB20 cylinder head.

You are going to be stuck with this, even after an increase in capacity, it will limit the final power potential.

The RB25 and RB26 have a far better cylinder head design, and thus a lot more potential for development. The best bang for your buck would be an RB25DET fitted with RB26 crank, rods, and pistons. This RB26DET would then take some serious bolt on external hardware without complaint.

Personally I would prefer this RB26DET combination to an RB30DET, but it depends on what you want I suppose.

Link to comment
https://www.sau.com.au/forums/topic/8478-rb24/#findComment-123839
Share on other sites

I remember reading some where that if you use the RB20 Pistions and RB26 crank it only strokes out to 2.1-2.2ltrs. Not much at all.

Really by the time you build the RB24 with new pistions etc the price wouldn't work out much different to a RB25.

Only advantage would be insurance and registration issues.

Link to comment
https://www.sau.com.au/forums/topic/8478-rb24/#findComment-123878
Share on other sites

I think they want to do it partly for the novelty factor, but also because when you build an engine like that you have control over bore/stroke ratios, compression etc, and therefore the result can often be better than many of the more common engines around.

I think it is a good idea, but to get the capacity you will need bigger pistons. Good luck with the engine build, keep us updated with the progress, photos etc.

See'ya:burnout:

Link to comment
https://www.sau.com.au/forums/topic/8478-rb24/#findComment-123930
Share on other sites

Yeah it is just something different, depends on the price but you may be able to get a motor built for similar costs to an rb25(you would still need the box though) and at least you know the motor would be right and not break in a hurry if its done right.

Link to comment
https://www.sau.com.au/forums/topic/8478-rb24/#findComment-123976
Share on other sites

It is a great engine if you want it to rev out. Lets face it rb20s rev out much higher and better than 25s, by increasing the displacement you have better mid range and the revy top end.

I too have had serious thoughts about it, but unfortunately the RB20 is such a fussy enginem the 25 starts to look like a good investment.

Link to comment
https://www.sau.com.au/forums/topic/8478-rb24/#findComment-124018
Share on other sites

Originally posted by meggala

ok I have heard of

rb 2.2, = tomei larger pistons only  

2.3 bigger pistons 81-81 mm with rb25 crank and rods

2.4 with the tomei pistons and rb26 crank and rods there is machinig requiered but not sure what

 

2.45 special hks cranks rods etc and dispalyed on my site

do a search on the sdu foums it has been disussed heaps personally I would only do the tomei pistons or copies 82 mm cause I know some one who made around 600 with this combo.

and decided againt the 2.4 kit cause and rb 25/26 was chaeper this was in japan

meggala

what about a 2.8, i've seen a special edition r33 gtst series II with 2.8 litre engine????

I think the r33 is an MR

Link to comment
https://www.sau.com.au/forums/topic/8478-rb24/#findComment-124101
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Latest Posts

    • I came here to note that is a zener diode too base on the info there. Based on that, I'd also be suspicious that replacing it, and it's likely to do the same. A lot of use cases will see it used as either voltage protection, or to create a cheap but relatively stable fixed voltage supply. That would mean it has seen more voltage than it should, and has gone into voltage melt down. If there is something else in the circuit dumping out higher than it should voltages, that needs to be found too. It's quite likely they're trying to use the Zener to limit the voltage that is hitting through to the transistor beside it, so what ever goes to the zener is likely a signal, and they're using the transistor in that circuit to amplify it. Especially as it seems they've also got a capacitor across the zener. Looks like there is meant to be something "noisy" to that zener, and what ever it was, had a melt down. Looking at that picture, it also looks like there's some solder joints that really need redoing, and it might be worth having the whole board properly inspected.  Unfortunately, without being able to stick a multimeter on it, and start tracing it all out, I'm pretty much at a loss now to help. I don't even believe I have a climate control board from an R33 around here to pull apart and see if any of the circuit appears similar to give some ideas.
    • Nah - but you won't find anything on dismantling the seats in any such thing anyway.
    • Could be. Could also be that they sit around broken more. To be fair, you almost never see one driving around. I see more R chassis GTRs than the Renault ones.
    • Yeah. Nah. This is why I said My bold for my double emphasis. We're not talking about cars tuned to the edge of det here. We're talking about normal cars. Flame propagation speed and the amount of energy required to ignite the fuel are not significant factors when running at 1500-4000 rpm, and medium to light loads, like nearly every car on the road (except twin cab utes which are driven at 6k and 100% load all the time). There is no shortage of ignition energy available in any petrol engine. If there was, we'd all be in deep shit. The calorific value, on a volume basis, is significantly different, between 98 and 91, and that turns up immediately in consumption numbers. You can see the signal easily if you control for the other variables well enough, and/or collect enough stats. As to not seeing any benefit - we had a couple of EF and EL Falcons in the company fleet back in the late 90s and early 2000s. The EEC IV ECU in those things was particularly good at adding in timing as soon as knock headroom improved, which typically came from putting in some 95 or 98. The responsiveness and power improved noticeably, and the fuel consumption dropped considerably, just from going to 95. Less delta from there to 98 - almost not noticeable, compared to the big differences seen between 91 and 95. Way back in the day, when supermarkets first started selling fuel from their own stations, I did thousands of km in FNQ in a small Toyota. I can't remember if it was a Starlet or an early Yaris. Anyway - the supermarket servos were bringing in cheap fuel from Indonesia, and the other servos were still using locally refined gear. The fuel consumption was typically at least 5%, often as much as 8% worse on the Indo shit, presumably because they had a lot more oxygenated component in the brew, and were probably barely meeting the octane spec. Around the same time or maybe a bit later (like 25 years ago), I could tell the difference between Shell 98 and BP 98, and typically preferred to only use Shell then because the Skyline ran so much better on it. Years later I found the realtionship between them had swapped, as a consequence of yet more refinery closures. So I've only used BP 98 since. Although, I must say that I could not fault the odd tank of United 98 that I've run. It's probably the same stuff. It is also very important to remember that these findings are often dependent on region. With most of the refineries in Oz now dead, there's less variability in local stuff, and he majority of our fuels are not even refined here any more anyway. It probably depends more on which SE Asian refinery is currently cheapest to operate.
    • You don't have an R34 service manual for the body do you? Have found plenty for the engine and drivetrain but nothing else
×
×
  • Create New...