RB24DET Build... Thoughts? Inputs?

[Chaos the Xile]

I am getting ready to pick up a '89 Coupe with a RB20DET in it. Car has bad compression on one of the cylinders and I was thinking of rebuilding it. I want to do something that is not done everyday with the RB20. So I figured I would try out a RB24.

Now I just purchased a complete RB26 short block for $150 from a buddy of mine, so sourcing the RB26 parts are taken care of. From researching I found out that I need a full set of 4agze pistons, and RB26 rod/main bearing. With a little machine work to get the RB26 crank to fit the RB20 crank journals, should be a fairly inexpensive build. The parts I plan on getting...

4AGZE PistonsACL RB26 Main/Rod BearingsARP Rod/Main/Head studsN1 Water/Oil PumpCrank CollarTomei Poncams (260degree)Tomei Type-A Valve SpringsTomei Cam GearsTomei Timing BeltStock Exhaust Manifold w/ 38mm wastegate flangeGarrett GT2876R Turbo555cc InjectorsAftermarket Fuel RailAeromotive FPRFront Facing Intake PlenumZ32 MAF

Now I am looking to achieve around 370-400whp looking for response more than anything with this setup. So Any input on parts or experience with this build would be appreciated!

[rbsileighty]

I'd highly recommend getting the car running with the RB24 setup before throwing a lot of bolt-on's at it... this way you can concentrate any potential issues and can expedite your troubleshooting... also I'd pass on a GT2876 and stick with a more eff pkg of that wheel in a GT3076... HTA if you can find one.

Interesting project... can't wait to see it come to life!

[l0nestar]

Looks interesting,And as rbsileighty said. get it running before adding bolt-ons.

[Yellow4g63]

I too have thought about a RB24 build. The magical part is the RB26 crank in good condition. I think you need to notch the 4AGZE pistons for the oil squirters on the RB block and shave down the blocks in a few spots for the rods to clear when it spins. Throw some eagle rods in it for the extra revs.

[Chaos the Xile]

So the 4agze pistons need to be machined... I saw on SAU that Cool made a set of pistons for this setup.... and why go 3076r over the 2876r? Like I said my main point of concern is Response..

[StricNyne]

man rb20 head dont flow that good, and machine work is not cheap, unless you want some uber custom setup just for s***s and giggles get a rb25 or a rb26. realistically a rb26 with swap components and few items is around 8k and thats generous, a rb25 is like half of that. its just not worth it unless you like throwing endless amounts of cash into a build. i was one of the people who tried like 30 original projects to be differant (twin turbo rb25 for starters....)and i now realize why no one else did it, it was not worth the power gains, the economical aspect, or work required to make it happen

[Chaos the Xile]

man rb20 head dont flow that good, and machine work is not cheap, unless you want some uber custom setup just for s***s and giggles get a rb25 or a rb26. realistically a rb26 with swap components and few items is around 8k and thats generous, a rb25 is like half of that. its just not worth it unless you like throwing endless amounts of cash into a build. i was one of the people who tried like 30 original projects to be differant (twin turbo rb25 for starters....)and i now realize why no one else did it, it was not worth the power gains, the economical aspect, or work required to make it happen

I have a RB25, but the Datsun the engine is going into needs some work and I need a car this season The RB20 heads aren't too bad I mean there is a guy in Canadaland that is running consistant 10's in the 1/4 mile with a stock rebuilt RB20. I am looking for response from the engine and with a mild port and polish along with supporting head mods I dont see why the engine won't do what I need it too. PLUS if you all remember the HKS drag skyline use to have a RB24 before they went to the RB26

[Bluefire]

A few people having done it in the past only means that its possible. It doesn't necessarily mean it was worth doing.... I think people really need to start by asking themselves what they want out of their car and then pick a motor and upgrades. Then you'll easily realize that if your power goals are 400whp, the SR would have been a much better choice. Or if your dead set on using an RB, I would probably just go straight to an rb26. Your RB24 build is going to end up running you between $5000-$7000, which is roughly what it costs to drop in an Rb26(which will do 400whp with boost controller and tune)

-Bluefire

[Chaos the Xile]

A few people having done it in the past only means that its possible. It doesn't necessarily mean it was worth doing.... I think people really need to start by asking themselves what they want out of their car and then pick a motor and upgrades. Then you'll easily realize that if your power goals are 400whp, the SR would have been a much better choice. Or if your dead set on using an RB, I would probably just go straight to an rb26. Your RB24 build is going to end up running you between $5000-$7000, which is roughly what it costs to drop in an Rb26(which will do 400whp with boost controller and tune)

-Bluefire

Well like I said, I am getting the complete RB26 bottom end for $150... With Bearing, studs, N1 Pumps, and 4AGZE Pistons I am nowhere near $4000-$5000. I have owned a RB20 S13, RB25 S13 and driven a RB26 S14, all nice but like I said I am seeking response from this package... and from what I have read on SAU this is a great package all across the powerband.

SR20... never an option, they are good for some people but not for me. If I made 350whp it would be fine with me. just looking for a responsive track car nothing too serious.

[RustspecS13]

Sounds good, since the biggest part of a RB24 build is the cost.

Though I was thinking about the rb20s advantage over the other rbs, and its it short stroke. And RB20+RB25= RB24. As in the rb20 crank/stroke and a rb25 bore would give a true 2.4L, like the rb24 nissan made over seas.

The only problem is rod length would not even be close with out custom pistons or rods. But it would rev like crazy and still be 2.4-2.5L with an over bore.

~Alex

[Chaos the Xile]

When you use the RB25 crank and rods you get a 2.2L and when you use the RB26 crank and rods you get 2.4L

[Lozer]

you have my attention! I want to see how hard this is and how it comes out.

[Sil240]

I believe he was talking about the rb25 block and 20 crank with a overbore to make a rb24 super over square motor. Super revvy

[RustspecS13]

Exactly what I was talking about. Since nissan decided that was the best way for them to make an rb24.

But it sounds like you can build a rb24 stupid cheap, so good luck. If that falls through let me know.

~Alex