Rb24 Build

[Footnah]

Hey guys, first of all I'm going to clear something up.

I have a GTS-4 and I have a spare RB20DET AWD motor. I'm not interested in a 25 and I don't want to go 26 yet until I'm ready to get 400kws out of the car. + The starting purchase cost is about the budget I have to rebuild this 20.
At this stage in time, I'm aiming for over 200 to keep me with a happy mix between street and track out of the standard 20.

Now, I've searched a bit and have found a few topics, none of which have answered my questions.

My understanding is I'll need a 26 crank and rods with 4AG-ZE pistons.
Which bearings do I need to use with this combo?
What diametre are the 4AG pistons? If they're larger, how much needs machining out of the bore?
Do the oil galleries line up?
What compression ratio does this leave me with? And is this okay for turbo (VG30)?
What does the stroke become with the 26 crank and rods?
Do the RB20 main caps fit the 26 crank?
Do I need to change anything in the top end?
Do I need an aftermarket ECU or is Nisstune okay for this?

I'm sure I've forgotten something, but if anyone could shed some light on this topic it would be much appreciated. I wouldn't mind having the first AWD RB24 (That I know of. Feel free to correct me to save further embarrassment).

Cheers, Cameron.

[StevenCJR31]

You will get a lot of info if you google it as this topic has been covered extensively before

[dopey]

I am planing on building one of these for my gtst, from wat I understand the 26 crank bolts in and the pistons you need are 82mm the block will need to be bored and the conrods small end bushed to suit the gugon pin, but as sed it has been done a far bit so all info needed will be some where

[Dale FZ1]

http://www.skylinesaustralia.com/forums/topic/164666-project-24/

Read away on this thread, the latest update is only a couple of weeks old. It didn't take that much searching

[GTScotT]

Crank, pistons, rods, bore, hone, gaskets, build, etc etc etc etc.. Lots of money.

But an RB25 from a Stagea can be had for under $1,500... And it will do your 200kw close to stock, plus is bolt in AWD.

You made the comment prior that you will go RB26 later, why? I know disney makes it out to be awesome but its really not that great. All RBs have the same oil control issues, and an RB25 has VCT to make up for the RB26s ITBs. Be it myself I would only bother with an RB26 if it came in the car.

My 2c.

[scotty nm35]

I keep getting shot down for suggesting the 25 neo is the best of the bunch, totally agree Scott.

[Dale FZ1]

Full agreement here too.

I never really understood the desire to reinvent the wheel with the 24 concept.

Neo 25 could be freshened and made really strong with fastener upgrades for not a big spend.

If ITB was a must-have then it's only a matter of having a bit of machining and fabrication nous.

Hotside upgrades are a well worn path for RB25.

For a 200kW target run a stock unopened Neo with a HG turbo. Very cost effective.

[wolverine]

Such a bunch of naysayers.

Why would you do the sensible thing when you can be different...for the sake of it?

[discopotato03]

Reinventing a square wheel . Can't see the point of strangling a 2.4L engine with 2L ports/valves/chambers/manifolds .

Its a bit like the people who started out with RB30s years ago with a much modified RB20 head . Spark fired diesel .

The practical economically viable solution is an RB25 Neo motor n box , that is serviced with - factory RB25 Neo bits .

If GTR is the dream just buy one , I doubt you could build one cheaper than you can buy one . And if you could it isn't a real one .

A .

[GTScotT]

Without creating a frenzy for building these cars an AWD NEO was sourced for 1,100 including all parts recently. I'll be helping a friend install it in the coming weeks.

Car is an R32 GTS4 with a spun bearing. Motor came with all accessories, including loom, ecu, and even the OP6.

Am encouraging him to sell the OP6 and replace with a HG 2IU off the bat. The only time I would encourage anything different would be if the car came with a working 20 or a partly finished 26 conversion. Otherwise I wouldn't bother.

Though I should note I have NO ISSUES with a working RB20. I like them quite a lot. We are simply discussing broken RB20s and intentions to make one into an RB24. For which I don't agree with the dream of a cheap RB24. Its an untruth.

[s13rb20]

Hey mate,

As helpful as the others comments where..

I have an rb20 in an s13 (rear wheel drive only) and have recently started building my own 24.

Parts so far..

tomei rb24 pistons, gudgeon pins and rings (arriving this week)

Kinugawa Nissan RB20DET RB25DET Stage 3 Upgrade Turbocharger

Compressor wheel: 52.5 / 68 mm (Trim 60) Turbine wheel: 65mm Exducer (Garrett Stage 3)

SplitFire Coils

rb26 crank and rods,

Haltech Sports Platinum pro2000

HKS 565cc Injectors

600x300x75 front mount intercooler

Z32 airflow meter

Haltech Map Sensor

Haltech Air Temp Sensor

Tomei Fuel Pressure Regulator

Aeroflow inline fuel filter

Turbosmart BOV (bolt on for rb20)

And more detail (of my build) in the rb20 dyno thread.

But to more directly help you.. read the following links, particularly the tomei stuff. Although some is in japanese the drawings are all you really need. I'll put a build thread up once I get the block machined in January..

http://www.tomei-p.co.jp/_2003web-catalogue/e036_rb20det.html

http://www.tomei-p.co.jp/manuals/pdf/rb24piston.pdf

http://www.importpartspro.com/1111820112.html

http://www.vividracing.ca/tomei_21_64mm_piston_pin_nissan_rb22_rb24_1013486221.php

http://www.tomei-p.co.jp/_2003web-catalogue/e053_RB20_piston.html

Some of those tomei parts aren't for sale anymore, put if you look around you'll be surprised what you can find. The tomei way is not the only way to do it, there are a few other piston combinations, so don't stress if you can't get the tomei gear.

Edited December 18, 2013 by s13rb20

[s13rb20]

My understanding is I'll need a 26 crank and rods with 4AG-ZE pistons.

As above, not necessarily. Probably the most readily available, and cheap for what they are.

Which bearings do I need to use with this combo?

I'll be using rb26, will verify in January after machining

What diametre are the 4AG pistons? If they're larger, how much needs machining out of the bore?

Couldn't tell you of the top of my head, anything over 83mm I wouldn't be doing. Tomei's are 82mm.

Do the oil galleries line up?

Can't confirm at this stage.

What compression ratio does this leave me with? And is this okay for turbo (VG30)?

Couldn't tell you without knowing the head gasket type, bore of pistons, and area left between head and piston when piston at TDC but in short, yes it would be fine for your turbo setup.

What does the stroke become with the 26 crank and rods?

73.7mm i think

Do the RB20 main caps fit the 26 crank?

I am planning on using 26

Do I need to change anything in the top end?

Head Gasket, would recommend changing head studs to something stronger, as I'm having problems with standards at 266kw/19psi

Do I need an aftermarket ECU or is Nisstune okay for this?

Nistune could do it, but personally recommend something better, but a platinum sports pro isn't affordable for everyone

Sorry if any of that is a bit vague. As i said, will put up a build thread down the track. ALSO, just want to point out, my 20 makes well over 200kw and it's no where near running out of nuts.. so you don't HAVE to do a 24 to get that kind of power. As I said, my dyno graph is in the rb20 dyno thread http://www.skylinesaustralia.com/forums/topic/103095-rb20-turbo-upgrade-all-dyno-results/page-19

[Rolls]

rb20 head sucks dick so even with the extra capacity it will be a slug of a motor, just get a stock 25 and be done with it, you can then set fire to all the spare money left over to give you the same warm feeling that the weird rb24 would.

Rb26 is worse than an rb25 neo for a street car anyway, save your money and just buy an rb25 neo straight up with VCT, amazing motor. Can be had for a little over a grand, spend $500 on a highflow and you have a 250kw motor with awesome torque, not far off an rb30 if you go a small turbo and keep the VCT.

Seriously go drive an rb25 and then say you still want a crappy rb24 that is barely any better than an rb20, don't forget the more powerful motor will be MUCH cheaper!

Such a bunch of naysayers.

Why would you do the sensible thing when you can be different...for the sake of it?

Because being different for the sake of it is dumb, there is a good reason why everyone does it one way, because it is cheaper and better than all the others. People often confuse being creative and coming up with something better than the rest with just doing it differently because you don't know what you are doing, the latter just results in an expensive money pit that is worse than everyone else's.

Edited December 19, 2013 by Rolls

[niZmO_Man]

just get a stock 25 and be done with it, you can then set fire to all the spare money left over to give you the same warm feeling that the weird rb24 would.

Hahaha