240z RB25det or RB26dett Swap

Hello and Welcome to my Thread!
Alright, was that a good start...haha, first thread ever for me. But anyways, my story; I bought a 1973 Datsun 240z which is mint condition and I want to make a motor swap this fall. I want something to make it "different" and to blow the doors off other cars. I was decided on a RB25det but I was just curious if anyone else here has done it before? And if so I need to know how it went by chance. I've heard it's a pretty well bolt in situation besides a couple mounts...is this correct? Also before I go too far, I wasn't sure if it was possible to put a RB26dett in a 240z simply? These motors are four-wheel drive and have a different block don't they? Or is this possible? I'm almost sure I will go with a 25 but I was just curious. Thanks for any help!
If I had some pics on the internet I would show you the car which is amazingly clean...maybe sometime soon! I got her for $1600! I think it was a steal, the guy had to move and needed to sell it!!

well either way, i'm fairly confident that you'll need to fabricate some custom mounts, or try and find someone that makes a swap kit. for it. you'll have to make yourself a custom driveshaft that mounts up from the rb25det transmission. if you're going to swap an rb26dett, you'll need to use an rb25det transmission.

another swap you could think of doing is a vh45de swap... it's a nissan v8 used in the q45 luxury car, and there is a swap kit done up for it (or in the making i'm not sure) done by speedline. (http://speedlinegroup.com/)

what kind of numbers are being seen from the vh45de?

what kind of numbers are being seen from the vh45de?

talk to Al for specifics but he says that little over 300hp stock.

little over 300 stock, with the vk heads, look for around 345, with an intake and a nice exhaust, you're looking at around 400... that's what's been floating around at least

I think I would enjoy the turbo better though...The v8 is too much extra metal to put out the same horse power anyways. I also like the idea of having the Skyline motor under my hood, it'll make me feel important. A little more class if you know what I mean.

And I've heard the stock driveshaft will bolt right up for a start...of course I would need a better one in the future. And the motor mounts are no big deal at all neither, that I can do myself.

But if anyone has done this before I need advice!

sure, having a skyline motor is nice, but having 600whp from a tt v8 is another thing..... if you're looking to build something that will make you soil yourself every time you get on it, then the vh is where it's at... you can either tt it or supercharge it... ask albert (ZGringo) about the potential of it.. it's just insane.

another thing is that the vh45de is probably lighter than the rb25det or 26, as they are both iron Bricks, and the vh is an all aluminum block. just depends if you want finesse and power, or some finesse and INSANE power....

Just to bust out some FYI:

talk to Al for specifics but he says that little over 300hp stock.

02 Q45 was rated 340hp and 333lbs of torque from the factory.

Just to bust out some FYI:



02 Q45 was rated 340hp and 333lbs of torque from the factory.

ehh..thats a little over 300hp for me. :lol:

ehh..thats a little over 300hp for me. :lol:


Yeah... 345HP or so for the newer Q's and 305HP for the older one's. I'm not sure on the years but the newer ones have the VK45 and the older ones retain the VH45 I'm pretty sure. I'm too lazy to do more research.

Well The VH45de puts out 278 hp with 292 lbs. of torque
The RB26dett puts out 280 hp with 260 lbs. of torque
The RB25dett is somewhere's underneath the 26.

I still think I will be going with an RB...
Any past experiences I still ask?

I talked to some people who said that the swap is basically a bolt in. They also say the RB's can run almost 400 hp without needing an internal strengthening. (more like 375hp to be safe)

But anyways I won't be doing many upgrades once I have it in, at least not right away...I can say this now but when it's in I will probably do the opposite..haha

Well The VH45de puts out 278 hp with 292 lbs. of torque
The RB26dett puts out 280 hp with 260 lbs. of torque
The RB25dett is somewhere's underneath the 26.

I still think I will be going with an RB...
Any past experiences I still ask?

I talked to some people who said that the swap is basically a bolt in. They also say the RB's can run almost 400 hp without needing an internal strengthening. (more like 375hp to be safe)

But anyways I won't be doing many upgrades once I have it in, at least not right away...I can say this now but when it's in I will probably do the opposite..haha

remember that everything in japan was underrated and is in ps not hp. japanese car manufcaturers made a pact not to rate their car over 280ps. so the numbers you see are totally underrated...the RB26DETT have dynoed 270whp so the motor is more like 320-350hp.

anyways, they are no where near bolt-in. i think the drivetrain tunnel needs to be enlarged for the SR it it is really gonna need enlarged for the RB25-26. but yeah...it is an easier swap than most other engines for the 240Z. plus remember you will need to wire the ecu through the firewall...also, im sure the shifter will not come through the floor board so that will need to be customaied somehow. alot of work but if you can do it or afford someone else to do it...it is one hell of a swap.

good luck!!!

oh yeah, RB20DET will probably be your easiest swap and it can handle 350-400whp on stock internals so i know the RB26 can handle atleast 450rwhp on stock internals, thats probably closer to 550bhp. so yeah, very strong motors that love to be modded.

I say drop in a VG30DETT....

I just learned the history about the "pact" today from someone else too. That's so crazy that they would go and rate it 280hp and really the RB26dett puts out like 325hp!! Just to make the Japanese happy... I'm definitly doing an RB, just not sure which one till the time comes this fall. Thanks for the help so far.

I just learned the history about the "pact" today from someone else too. That's so crazy that they would go and rate it 280hp and really the RB26dett puts out like 325hp!! Just to make the Japanese happy... I'm definitly doing an RB, just not sure which one till the time comes this fall. Thanks for the help so far.
I got a few pics of the car in my photo gallery!

sweet dude that looks awesome.

I just learned the history about the "pact" today from someone else too. That's so crazy that they would go and rate it 280hp and really the RB26dett puts out like 325hp!! Just to make the Japanese happy... I'm definitly doing an RB, just not sure which one till the time comes this fall. Thanks for the help so far.
I got a few pics of the car in my photo gallery!

well, good luck and keep us posted. if you have any questions, im sure we are all here to try and help get it answered or recommend someone to talk to.

it is pretty crazy that the Japs did that but in other countries, people have a little more concern about keeping their words and being "good" people, unlike the US. alot of places, its about pride and reputation than money...the good guy always comes out on top.

for the SR20det into a 240z the transmission tunnel doesnt need to be stretched out and neither does it with the rb25 transmission, if it were a 70-72 240z you would need to shave off the ears inside the tunnel and weld in new ones for the new transmission mount that would need to be made. There is a guy named Rick Wong that makes straight drop in motor mounts for these conversions as well, and our shop also does these swaps but i dont know where you are located. Rb25s ive seen in some 240sxs with almost 500whp and stock internals. Even SR20dets have been held up to 554whp on completely stock block. RB26dett have been seen to hold insane power up north of 800hp+. For the RB25 to fit into the 240z you would also need these parts to clear the front crossmember:
11110-20P00 RB20DET Oil Pan (Rear Sump)
15050-20P03 RB20DET Oil Pickup
15059-V5001 RB20DET Oil Pickup O-Ring

for the SR20det into a 240z the transmission tunnel doesnt need to be stretched out and neither does it with the rb25 transmission, if it were a 70-72 240z you would need to shave off the ears inside the tunnel and weld in new ones for the new transmission mount that would need to be made. There is a guy named Rick Wong that makes straight drop in motor mounts for these conversions as well, and our shop also does these swaps but i dont know where you are located. Rb25s ive seen in some 240sxs with almost 500whp and stock internals. Even SR20dets have been held up to 554whp on completely stock block. RB26dett have been seen to hold insane power up north of 800hp+. For the RB25 to fit into the 240z you would also need these parts to clear the front crossmember:
11110-20P00 RB20DET Oil Pan (Rear Sump)
15050-20P03 RB20DET Oil Pickup
15059-V5001 RB20DET Oil Pickup O-Ring

hey, thansk for the info. i must ahve been mistaken about the widening of the tunnels. i thought for sure someone had said the tunnels needed to be widened. have you seen anybody who has swapped in a RB20DET in a 240Z??? seems liek the RB20 would be more of less a straight shot in there...

hey sr240z, how hard is it to source the sr20det's out of the nissan pulsar GTiR? i've been reading up on them and apparently they've got stronger internals than the other sr20's

Sweet, I didn't want to have to make the tunnel larger. Finally someone who has had some experience with this sort of swap; haha. My friend just recently put an sr20det in his 240sx and I need to blow him away next year with my rb! Does anyone know if the Infinity J30 rear end fits a 240z or what rear end with limited slip would?

the rb20det into a 240z isnt as hard as it seems, we actually did one as well for a customer who is on this board as Terminal Velocity, here is the link to pics of the swap on our site http://www.vildinimotorsport.com/gallery/mattrb20.html

if you are going with either an rb20det or an rb25det i would definitely go with a 4.11 LSD. you can get a r200 4.11 out of the nissan 200sx turbo from 85-87 i believe but they dont come lsd you would need to put an lsd unit into it. i say a 4.11 because those motors in the skyline gts-t came with 4.375 rear ends so the transmission are geared for that rear end, a guy on hybridz.org is running an rb25det with a 3.70 lsd and 3rd gear goes to about 119 mph, good if u want to be a freeway runner but not too quick reving. as far as the pulsar gti-r motors, yes they are stronger internally and have found out recently that they also have individual throttle bodies, they arent really hard to come by i can probably source one out if needed.

I have a 1980 280zx, does anyone make a kit to put the vh45de in that?

i'm sure the 240z kit will either drop right in, or take very little modification to work..

remember that everything in japan was underrated and is in ps not hp. japanese car manufcaturers made a pact not to rate their car over 280ps. so the numbers you see are totally underrated...the RB26DETT have dynoed 270whp so the motor is more like 320-350hp.

Yea...I read an artical about a test they did on a skyline...it's rated at, what, 287 hp from the factory?...something like that. Damn thing dynoed...like...300 or 310 or something AT THE WHEELS. Japan has restrictions on the power their cars can make...to get around this, the makers just lie...I guess...lol

I say drop in a VG30DETT....

...or a built VG30ET...like I plan to do...:biggrin: Can we say CHEAP!?

Yea...I read an artical about a test they did on a skyline...it's rated at, what, 287 hp from the factory?...something like that. Damn thing dynoed...like...300 or 310 or something AT THE WHEELS. Japan has restrictions on the power their cars can make...to get around this, the makers just lie...I guess...lol



...or a built VG30ET...like I plan to do...:biggrin: Can we say CHEAP!?

yep, and i think that myth that the Japanese 300zxTT's have different, smaller turbos is wrong. i will confirm because i have both lying around but i think everything is equal throughout the turbos.

and yes i just read that when Europe received the R34 GTR, it was dynoing well into the 320whp range. thats crazy when it is only supposed to be rated at 280ps which would make it about 230whp. a good ~100whp underrated, not bad. :lol:

not that this matters but chevy underrated the LS1 camaros alot too. this was because they didnt want people to know that you can get corvette 1/4 mile and dyno numbers in a car ALOT cheaper, offered by the same company. :nono:

They gotta make their money. Like how the Altima will never be all it can be...don't wanna step on the Maxima's toes...the Maxima will never be all it can be...don't want it interfering with the draw of the 350Z's performance...and so on and so on...

Their really arent any engine swaps into this car that are as cut and dry as some have made them out to be... the 2 swaps that would be the most simple would be the Chevy SBC and the L28et, basically any other swap will take a VERY long time unless you have a lot of experience and are able to dedicate 100% of you're time to you're car. Not to mention, engine swaps get very pricey. Go to www.hybridz.org and very soon you will see how long it has taken most of these guys to complete their swaps. (hell, some of them arent even done and have been at it for 2-3 years) Also, if you do get an engine that was only sold in japan, where are you going to buy common replacement parts for it? things will just keep adding up and adding up. But, if you're really confident and have lots of time/money...go for it. But, spend lots of time on Hybridz, and try finding some people in you're area that can maybe offer some hands on help.

good advice al.. i think that's the part a lot of people overlook in doing any sort of large project... planning is half the battle:p

I Agree with alot of what you said Gringo, if the person isnt just a dreamer and has some skill, the spirit, the resources and the time to do an engine swap, it can be done in a reasonable time, and without too much hassle (if, like you said, they do a considerable amount of planning way beforehand). I was just trying to say that engine swaps require lots of dedication and, depending on what you're doing, a considerable amount of funding. Seeing 100's of threads on Hybridz about how guys want to do these complicated engine swaps in "less than a month" and also seeing how many swaps are 1/4 way finished and forgotten, i just felt like i needed to encourage the fact that it will take plenty of time and effort. So, all in all, i agree with you Gringo, Make sure you have some people to help, set aside plenty of time, be ready for lots of troubleshooting, plan plan plan, and you can get pretty much any damn crazy swap done.

P.S, i cant say i have done an engine swap into anything i personally owned, but i have helped on a couple, My friends Mk.II Supra, and my brothers B18 Civic. I dont know anywhere close to as much as you Gringo, but i think for a 16 year old, i know my way around a car. :)

Wish I'd done something like that. Start sweeping someone's floor or taking out someone's trash or whatever just to get in the door. After that, just wait for an opportunity, the whole time learning all I can. I'm still young (21) and still think about doing something like that. I already have a culinary arts degree (that I've had for about 2 years now) but I have a list of things I want to go to school for. I'm going to an invitational week long guitar seminar at Berklee College of Music in Boston in August. It'd be a dream to get paid to play and make music. Do that while I'm young, then maybe get my CDL and drive around for a few years. Then get my MCSE Certification and spend a few years sitting at a desk, resting and making 29386592834 bucks a year. And my "to go back to school for" list goes on and on and on. I never got how people worked one place for...like...45 years or something...that's just unfathomable to me. I've been cooking (amongst other things) in restaurants since I was 15 and I already kinda wanna start doing something else...just to learn, if nothing else at all.

Do that while I'm young, then maybe get my CDL and drive around for a few years.

Even just picking up and delievering medium duty trucks cross country I can tell you that you really, really have to like being out on the road to do it. It's long hours, alot of paperwork, and alot of tedious boredom. You get to go places you never would have been otherwise, and the scenery is usually pretty nice, but it is something you would really have to like doing it even just to do it for a few months straight.

I've always thought it would be something I'd like to do. My girlfriend is telling me not to do it, of course, but I still want to. I know there are some companies that give you reasonable home time.

45 years of cooking...fuuuuuuuuuuuuuuuuuuuuck that. There's no way I wanna do the same thing my whole life. COULD I? Sure. Do I WANT TO? No. I definately have the passion and drive. I can and will do anything I damn well feel like doing. The only thing I've ever actually failed at that I actually tried to do was the physical test for the Florence Police Department. Did it all (with 3 days notice,at that) except for the mile and a half. I've never been a long distance runner. My calves were cramping SO BAD from the previous run (400 meter or whatever, which I completed) that there was even LESS of a chance that I was gunna be able to do this mile and a half in the alotted time (16.15...sounds easy but it's not if you're not a long distance guy.)...which sucked cuz I already did the push ups, sit ups, bench press, and the 400M run (or whatever it was...3/4 around a 1/4 mile track...whatever that is). Waiting till they do the testing again...I WILL get it this time.

As for all the other shit, I'm seriously thinking about trying to get just some lame, low paying, easy job at the local shop I take (and have BEEN taking) my car(s) to. I don't even care what I'm doing. It's a place called Superior Imports and I've taken every car I've ever owned there (all 3 Zs, and the Celica...not the Prelude) and my dad has taken the only Porsche he's owned while in Kentucky there as well. GREAT shop. Dude named Dan has been doing it for...like...30 years or something crazy like that. He'll tell you what's wrong with your car before even looking at it 9 times out of 10. It's just so EASY for me to get a decent paying job in restaurants.

All in all, I will do all I want to (want to go to school for music, which I am in august, want to go to school for my MCSE certification, want to go to school for cars or engines or engineering or something to that effect and I'd like to get my CDL. I'd like to learn how to/be able to drive anything/damn near anything on wheels...and I think I already have a decent start at it....driven cars, big and small, as well as trucks big and small...or should I say, medium and small...time to move on.

Id go with a RB25. still great power but for less cost. and you can get a rwd rb25 tranny too. i have motor mounts, wheel flares, rear strut(use for bucket seats to attach to), coilovers, rb25 twin fan radiator(runs $400), new dash, and new front lip
My project went to shit because the body had stupid issues later on. Im selling all these parts, none of them have been used or even left my house. let me know if youre interested. i can hlep you with engine issues too. im doing the swap into a 350z now

10 years later and the thread is revived. Crazy to think that it has been that long.. I ended up selling the car to pay my property tax and never got to do what I had planned. I had a heavy heart and many conversations with others over the fact that it was as clean as it was, it wasn't right to swap it. Went through a few other builds since then with a WRX but someday down the line I will find a Datsun needing restoring and make the swap. If not.. Maybe a real R32 or R34 will roll into the garage...