RB26 to RB25 head...internals...

[Nalfein]

Will an RB26 head fit on an RB25?

I'm asking cause I wanna do an RB25 swap into an s13 but I've heard the 26 head revs better...

What about internals...? I know the 26 internals ie: crank, rods, pistons are stronger will they fit in the 25 (and how will the change specs like compression and displacement) or would it be cheaper and/or better to find some after market rods pistons for the 25. I plan on making 500 hp.
Where could i get a hold of some after market internals for the 25?

By the way my names Matt, I'm 20 and new to this forum... just trying to tap into this deep well of Nissan knowledge before i go and spend a shitload of money.

Thanks in advance

(I'm from Vancouver Canada)

[raysoh8]

rb25= 2.5 litres.. smaller cylinder?
rb26= 2.6 litres.. bigger cylinder?

so the piston wouldnt really fit eh.. or maybe not

[Sneezer]

Nalfein

I'm looking for the same answers as you are. If you get them please let me know.

raysoh8

The bore is the same in both engines it's the stroke that is diferent. RB26 is 2mm longer stroke.

[RBS14]

Originally Posted by Nalfein

Will an RB26 head fit on an RB25?
I'm asking cause I wanna do an RB25 swap into an s13 but I've heard the 26 head revs better...
What about internals...? I know the 26 internals ie: crank, rods, pistons are stronger will they fit in the 25 (and how will the change specs like compression and displacement) or would it be cheaper and/or better to find some after market rods pistons for the 25. I plan on making 500 hp.
Where could i get a hold of some after market internals for the 25?

Yes the 26 head will fit. You will need to drill the block for 12mm head bolts and maybe use a 26 headgasket to block the 25 vct oil feed.

Yes with proper bearing selection you can use rb 26 internals, with a 26 head you will basically have an rb26. CC volume, compression, etc will be the same as an RB26.

But if your only looking for 500hp just get some Arias forged pistons (cheap) polish and shot peen the rods, use ARP head studs and rods bolts.

Check out my website, i nthe forums I posted a list of websites that carry RB25 parts.

[hdtboy]

Why not use an rb30 bottom end? no substitute for cubes

[RazorGTR]

Originally Posted by RBS14

Yes the 26 head will fit. You will need to drill the block for 12mm head bolts and maybe use a 26 headgasket to block the 25 vct oil feed.

Yes with proper bearing selection you can use rb 26 internals, with a 26 head you will basically have an rb26. CC volume, compression, etc will be the same as an RB26.

But if your only looking for 500hp just get some Arias forged pistons (cheap) polish and shot peen the rods, use ARP head studs and rods bolts.

Check out my website, i nthe forums I posted a list of websites that carry RB25 parts.

The bores between the two are identical! It is the crank and rods that are different.

The craddles are also different but you don't have to go to an RB26 craddle. As far as mating the head yes it will go on as mentioned.

Keep in mind the RB25 block isn't as strong as the RB26 one, and the crank is substantially weaker. It will handle 500hp without troubles though. As mentioned forged pistons (JE, HKS, TRUST, JUN,) all make quality parts with JE's being the cheapest in price. BTW just for your information, Trust use JE blanks