Rb25det Variants .

[discopotato03]

Hi all , am learning about RB25DET differences because I like to take advantage of factory upgrade engineering when possible .

It was said that compared to the R33 version the R43 Neo engine uses larger exhaust valves , solid buckets and different chamber and piston crown design . If the chamber is shallower I guess the piston dish must be deeper meaning Nissan could have been looking for better anti detonation qualities and no doubt lower emissions .

If these engines use RB26 type con rods then that would also mean larger gudgeon pins wouldn't it ?

I'm beginning to wonder what needs to be changed to fit the Neo engine to an R33 electrically speaking . To have the late VCT working properly would mean the R34 loom and obviously the ECU .

Has anyone been down this road ?

And no don't want an R34 Skyline .

Cheers A .

[r33_racer]

i heard they have hydraulic lifters, and the valve springs are considerably weaker then normal r33 rb25 and they suffer from valve float quite easily. That came from a workshop....so i dont know how much truth is in it.

[Adriano]

The NEO definately has solid lifters, and a different vct system ive heard(although it looks the same)The combustion chamber is much smaller than the r33. the NEO has 34mm inlet and 30mm exhaust valves

[brizzi]

Go the neo! Im not bein biased but i had a r33 series one engine in my old r32 it wasnt as smooth as the neo and wasnt as torquey. I got 170 kw atw on 12 psi front mount, exhaust etc etc. The neo has all the same mods and puts out more on standard boost.

[Guest 40th-edition]

Man this NEO thing has me stuffed on what cars have these engines and how to tell the diffrences????

[brizzi]

They are still rb25 det they came out in the r34gtt. The head is different, throttle body they have a different cover on the engine, solid lifters,stronger rods,different pistons,bigger exhaust housing on turbo. Keeps its legs all the way to redline! Not like the old ones they run out of puff bout 5800rpm! And they make 19kws and 50nm of torque more than the r33 rb25...

[Munna1]

The R33 RB25DET has NVCS on the inlet cam only the Neo has it on both the inlet and exhaust

cheers