ProricanRacer

Hey everyone...I'm new to the forum...as a matter of fact I just bought my 1991 240sx SE fastback last night. I have been doing alot of searching and found out that the most popular engine swap for the 240 is the Sr20.....but I want to mix things up a bit. I want to go with the Rb25det and I have found a place that sells the motor for $2,500 plus shipping. I'm ready to buy it....however I want to be absoluteyl positive that this is the smart move to make. Is there anything negative or anything that may give me trouble with the Rb25det that perhaps the Sr20 may not?? If anyone can give me some pros and cons on the Rb25det vs. the Sr20det.....it will be greatly appreciated. Thanks!!

-HyJynX-

Hmmm..first of all what do u plan to do with the car? (IE, drag, daily drive, show,autoX,drift?)Is 2500 for front clip or a motor set?? If its a motor set id suggset getting front clip, it might cost a extra grand but its WELL worth it.

Bryan

Like Jynx said, I would definately get a whole front clip, it's a little more expensive but in the end its worth it. And as for compared to swapping in the SR, I believe the RB takes a little more fabrication to make it fit, but it will all fit in there and you will have a beast of a car when its done. Good luck with everything

PSI

First of all, RB series is a great engine. You will need motor mounts, driveshaft made,wire harness is a biatch, there are a few different types of RB25's ( R32/R33) each with its own quirks for wiring.

Pros:
Great Power Potential
amazing torque
Cast Iron block with full girdle
Bulletproof internals
Great Power Potential

Cons:
Added weight over SR- it is only about 50 or so pounds but if you plan on running suspension it really limits your ride height. Ours has lowering springs on it and it sits about an inch off the ground.

Parts sourcing is a complete PIA- The simplest things take 3-6wks to get (ex. water pump, timing belt,etc) And if you do find someone in the states who has them , they are usually marked up 200%

Expensive to upgrade to Front mount as you need a new intake manifold.

My advice to you would be one keep looking for a cheaper RB- 2500 plus shipping is alot. And get a front clip!!!! Dont do motor set, it is helpfull to see how it sat in the skyline.

And unless this is your second car and you dont plan on daily driving, get an SR S13 and mod the hell out of it. You will be much happier down the road.

Hollowpoint

wow dude i like the price on that rb but is it a motor set or front clip everyone says to get it so im thinking of getting the front clip. im planning to do the same thing aswell silvia front end with rb25 i dont know what i want the car for yet (drag or drift) but im thinking of just making it a sleeper. u should talk to (jonpowell)
hes on these forums he's got his 89 with rb25 in it looks very nice and good luck with your car

ProricanRacer

Wow, thanks for all the responces, I actually don't know what I want as well....I guess I am leaning more towards drag than drift....and I always assumed that since everyone that has Sr20 uses their 240 to drift, than the Sr20 is best for drifting and the Rb25 is best for drag....but what do I know?? I'm as new to this as the next guy.

But thanks for all the info....I just don't want to go swap a Rb25 and then a couple of months down the road regret it and wish that I woulda gone with the Sr20.

As for the extra 50 lbs.....I hear that alot when it comes to comparing the Rb and Sr....but I think it's a non-factor for me since I weigh onlly 134lbs.....hehe...but yeah...

I guess I'll just do some major debating while still trying to gather enough dough for when the time comes to do the swap....all I know is that I want this monster ready for spring time so I can gain some respect from the other 240 drivers at the "street scene" who steal the show on a weekly basis with their 240's...

But thanks agian for the replys....I can still use some more....thanks!

Sil40_Mayhem

well, looks like most of ur questions have been answered already. see, isn't this a great place to be? anyhow, the general consensus is that the RB series would be supremo for dragging (considering their weight, being 6 cyl, strong guts, etc) and the SR would be better suited for more handling oriented situations. that's NOT to say that either one couldn't do both, but rather, that would be the preferred arrangement out of the box. it all boils down to what u ultimately wanna do w/ur car, how much dough ur looking to unass, and how much downtime u can afford. i dunno if u even considered other options, but there is also the CA18DET, RB20DET, and custom KA24(D)ET.

oh, and don't worry about gaining the respect of fellow 240 owners. that will come automatically as long as u love ur car and are not a complete and total jackass. u don't need to have nitrous, candy paint, and 600whp to get love w/this crowd. we're just different like that.

drnovascotia

they've done an excellent job.

If you have the $$, go for it. With the RB engines, you're gonna need custom engine mounts, and have some modding to do to make it fit and look right, whereas the SR20 just slides right in, thats another thing to consider. You could rebuild the KA and even go KAT if you wanted. Lots of options, figure out what you want and we'll go from there.

Dr.

TruDirtyPlaya

Check unstablehybrids.com good site for radical 240 swaps... they dont do swaps anymore, but supplie wiring harness and engine mounts