What's better...?

[r34drifter]

An RB20 or an SR20, SR22 is there an SR25? or in other words, what's the best Turbo Nissan/Nismo 4 cylinder egine you can put in a 240sx/S14?

[turbo15]

There all good engines...but i would go with an RB20

[r34drifter]

Originally Posted by turbo15

There all good engines...but i would go with an RB20

see because im thinking that the RB20 is good because of course it's the skyline's, but im also thinking that the others will be better because they're newer

[nismoron]

The RB20 is a 6 cylinder and is a n easier swap than the SR. I've done both. The RB20 costs HALF as much!!! And I have kicked every SR I've ever raced's A$$!!!

I bought my motor, had it shipped, bought HKS filter Uras JDM exhaust and HKS boost controller for the price that my friend paid for an SR BEFORE it was shipped!!!

The RB head will flow more air and has a MUCH better valvetrain design. You dont see rocker arm stoopper kits for an RB because they dont sling rocker arms at high RPM. Rocker arm stoppers are a must for any performance SR.

[nismoron]

The SR22 is a Sr20 with a stroker kit. It is not made by Nissan. There are kits from HKS and Tomei. Wanna get really neat?!? Try a RB24DET! It's an RB20DET with an RB26 crank and modified rods with Tomei pistons to fit the RB26 rods. Rally NASTY!!!

[r34drifter]

Originally Posted by nismoron

The RB20 is a 6 cylinder and is a n easier swap than the SR. I've done both. The RB20 costs HALF as much!!! And I have kicked every SR I've ever raced's A$$!!!

I bought my motor, had it shipped, bought HKS filter Uras JDM exhaust and HKS boost controller for the price that my friend paid for an SR BEFORE it was shipped!!!

The RB head will flow more air and has a MUCH better valvetrain design. You dont see rocker arm stoopper kits for an RB because they dont sling rocker arms at high RPM. Rocker arm stoppers are a must for any performance SR.

you're right, i always thought an RB20 was a I6, until i saw this picture, but never read it. I was like wtf?! It can't be 2.0L I6, and then i saw 4 cylinders in the picture, but now i realize the other 2 aren't shown. so thanks, RB20 is the way to go

[thedguy]

while i'm not gonna refute anything nismoron says. Just because the engine is from a skyline doesn't make it all of sudden the greatest thing ever. I don't mean to be an a-hole (not trying) I just seem to hear so many oooh and ahhh aboutthe skyline and it's motor.

I haven't read all the specs on the 2 motors, I personally think the SR20 is only any good because it's aluminum and fairly robust for it's size and wieght.
All things being equal a 2.0 6 will be capable of more power than a 2.0 i4. I do know the RB20 is quite strong, and same with the SR20, the SR20 wasn't originally ment to be a performance motor (the CA18det and RB26 were) it just kinda happened. Evidence being the rockers with teh SR20, where the RB/CA engines don't use rockers.

Nismoron, would u mind elaborating onhow the RB is an easier swap than the SR? I was under the impression that an SR was for the most part a direct swap, and RB had to have many things custom fabbed.

[nismoron]

The RB just bolts right in (like and SR0 if you buy the motor mounts. If you use the skyline crossmember there are some issues, but I have never tried it that way. The RB harness requires less wiring and modification to connect to the US 240 chassis. The only fabbing is for a throttle bracket ans a down pipe. I bent the trottle bracket out od an aluminum bar and just used a file to cut a slot for the cable to rest in(15-20 mins). The down pipe, you just cu the skyline pipe in half. Test fit it in the car and tack weld two 45degree 3in steel elbows to it(they bend around the steering shaft). Take it out and weld it up correctly. That took us about 2 and a half hours because we had bought the welder the day before and no one knew how to use it. Its harder than it looks to weld steel piping. Now we could make on in less than an hour.
All of the skyline intercooler piping bolts straight in. Tha main thing is the wiring harness is LESS pain in the ass. Everything else is equal Except that an RB costs HALF what the SR costs

[thedguy]

So the RB/skyline motor mounts work fine in the s13 and s14 chassis without modification? How's the weight balance, or have you not been able to get it corner weighted? I'm curious how much more weight the engine adds vs the stock Ka24 and SR20 and also how much it changes the balance. I'm assuming since it's a cast iron 6 it's gonna add a bit more weight over the front, and more weight in general than the sr20, and only prolly only a little over teh ka24

[r34drifter]

Originally Posted by thedguy

So the RB/skyline motor mounts work fine in the s13 and s14 chassis without modification? How's the weight balance, or have you not been able to get it corner weighted? I'm curious how much more weight the engine adds vs the stock Ka24 and SR20 and also how much it changes the balance. I'm assuming since it's a cast iron 6 it's gonna add a bit more weight over the front, and more weight in general than the sr20, and only prolly only a little over teh ka24

one more question, do you have to change the computer of the car when you put an RB20 because i've heard you don't have to do it with an SR20 or SR22.

[CRISTIAN]

I've heard the FJ20's were the best 2.0 nissan made.

RB20 sounds like a great choice, I just wonder how much longer it is than an sr, because weight in front of the front tires just isn't good.

[thedguy]

Cristian I've heard the same about the FJ20. Unfortunately thats all the info I can really find on the motor. I know Adam Corolla has one with twin 2 barrel carbs on his BRE Replica 510.

[CRISTIAN]

Yeah my brother read up a lot about it and wouldn't shut up about how cool it was for like a month. I personally don't know much about it.

[nismoron]

The RB does NOT use the same mounting spots. You have to buy motor mounts.But even with that cost it is still MUCH cheaper than an SR!

It adds 70 lbs over the KA motor, but some of that is behind front wheels as well (turbo/downpipe). The overall balance is changed a little, but not badly. It still handles better than most cars and does not lose it's nimble character. It is of little concern. Add a speaker box to the back and it balances back out

The RB needs an RB computer. An SR needs an SR computer and a KA needs a KA computer. They are all different. The KA and SR are 4 cylinders, but the SR has 4 coil outputs for the ignition, the KA uses a distributer. Even if they would run each other. The SR has a different fuel and ignition curve (VERY important underboost).

I dont understand why you would even ask though??? The computer comes with the engine and bolts into the kick panel with one 10mm bolt. Not hard to change. You have to take all of that stuff apart to wire the engine harness anyway!

[Eddy_Wu]

i say all are good one's and i dont know about what do they have inside