I'm Thinking RBs - The Differences Between R32, R33, and R34 GT-R Motors

If you've been following my Progress Bar posts about the ongoing restoration and build of my Nismo R32 you'll probably have seen me point out that the new Nismo Fine Spec motor that's in my car is an R34 spec version. To most people that may seem like a minor detail since the R32, R33, and R34 all have the same RB26DETT motors...but that's not really the case.

Yes, all three generations of RB-powered GT-Rs had the same basic motor but it shouldn't come as a surprise that in the 14 years between the debut of the R32 in 1989 and the end of production for the R34 in 2003 that Nissan made certain changes both internally and externally. As a result, it's not simply a matter of taking an R34 motor, plunking it into an R32 engine bay, turning a couple of bolts, plugging in some connectors, chugging a couple of Sapporos, and hey presto, you just gave Godzillla a heart transplant!

If you plan carefully and can convince a lion and a tiger to get all lovey-dovey and forget the minor matter of being from different species you end up with a cool-ass hybrid called a liger, which is the largest and therefore instantly the most awesomest big cat there is. If you don't plan carefully then you can end up with just a lot of hairballs to clean up. It's the same way with trying to make a hybrid of RB26 motor and Skyline chassis from different generations so to help any of you contemplating doing such a thing I've compiled this handy chart so you can plan ahead:

R32 R33 R34
Front final drive gearing
Same – 4.111
Exhaust cam/cam angle sensor
Different – CAS has black plastic cover
Same - module separate from coil packs
Integrated with coil packs
Different unit and wiring
Oil pump drive
Old style (up to 1993?)
Improved version
Timing cover

Why would you even be considering such a swap? Well, if you have an RB26 and something drastic happens (such as say, one of your main bearings decides to unfriend your engine block) then you may need a replacement motor. Replacement used RBs are fairly easy to come by online so if you're going that route and thinking of buying one and swapping it in rather than rebuild the original it pays to know what you'll be in for if the one you're eyeing happens to be from a different generation of car.

Let me elaborate on the details I've put on the chart:

  1. Front Final Drive – the R32 and R33 had a five-speed tranny while the R34 upgraded to a six-speed Getrag. Nissan therefore had to change the differential gearing to suit the new gear ratios in the newer transmission and since the front diff on the RB is integrated into the oil pan that means if you pick up an R34 motor you'll need to swap the gearing or the whole oil pan/diff assembly if you want to use it in an R32 or R33, and vice versa. My car was getting a new expanded oil pan so we had to swap the diff anyway.
  2. Exhaust cam/Cam Angle Sensor – the R34 has a different exhaust cam versus the earlier cars and a different cam angle sensor mated to it. That means you need to repin the CAS connector on an R32/R33 engine harness so that it'll play nice with the different CAS if you're using an R34 motor.
  3. Igniter – R32s and R33s had an igniter module screwed onto the coil cover. In the R34 they decided to get rid of the separate igniter and go with coil packs that had them integrated. You can use the older setup on the R34 motor but it's also an option to convert the R32/R33 system to the R34 setup like I did on my car since my igniter module was already wonky. I talked about a ready-made kit to do that in this post.
  4. ECU – the R34 has a slightly different socket for the ECU than the older cars so you can't just swap ECUs. This was partly why I went with a standalone ProEFI ECU on my R32.
  5. Oil pump drive – the RB26 was originally designed with a crankshaft that had a narrower than ideal engagement surface for the oil pump drive. This was improved on later versions to reduce the chances of oil pump failures. Some sources I've read say the improvement was made as early as the 1993 R32s while some say it didn't occur until the R33 was introduced. Be aware of this and if you want to be safe, check the crank to see if you've got the improved version. If you don't then you may need to plan for a replacement/modified crank or a spline drive conversion in the future if you want peace of mind.
  6. Timing cover – just a minor difference but the older cars had a cast metal timing belt cover while the R34 got a plastic one.

Lastly, the various RBs also had some minor changes made because of the different engine bay shapes - namely the coolant pipe and heater hose connections were slightly different so those need to be swapped around to fit a different generation engine properly.

All of this is just an introduction basically to the bewildering world of RB26s since there are numerous variations on the theme from Nismo, HKS, Tomei and so on. The RB family has been around for so long that you'll run into various crate motors and funky hybrids that would make for a much, much longer post so I won't get into those here. Maybe in the future I'll touch on them but for now, drive safe and enjoy wrenching on your cars!


  1. HKS and Tomei built their own RB26's?? I think you've got the cream of the crop with that final edition Nismo one right there. I'm thinking Nismo should build some more due to the US craze going on right now.

    Regarding the oil pump drive, I hear from the majority of sources that it was widened on the Kouki R32s (February 1993 - December 1994). I'm hoping to hold out until 2018 to get one of these and that the prices drop some...

    1. Tomei still offers their Genesis crate motors but they are seriously expensive:


      I'm not certain that HKS offered complete crate motors by themselves but they did offer their own blocks and pretty much everything to put together an RB26 including their famous 2.8 stroker kit as well as completely built cars with the Zero R:



      Mine's also offered crate motors:


      As for Nismo, their best RB ever was the Z2 in the Z-tune (all the best bits including a GT-spec block) but you can still get the R2 custom-built which has similar specs but based on "just" an N1 block. The R2 has even better components than my Fine Spec but of course it costs a bunch more lol.

  2. The R34 exhaust cam was different to the R32/R33 not the intake cam. R33 series 2 & 3 also ran coil packs with inbuilt ignitors.

    1. Oh yeah, duh! Must have had a brain fart when I typed up that part, not sure why I put intake instead of exhaust since it's obviously on the exhaust side lol. Thanks for the correction. I'll have to do some research on the R33's also using the built-in ignitors - that's the first mention I've heard of the change being made that early. Thanks for the info.


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