Noob here to the RB scene

[ARA300ZX]

I've been in the Z32 game for the past 12 years and am nearing my completion on the VG build and restoration. With that being said, I just got my hands on a RB25 s2 block and heads. I do not know much on these motors and will do as much research as I can.

I've been told a lot of these RB parts are interchangeable. Can I use RB26 pistons and rods on the RB25? I will be using the RB25 crank. I'm just able to get an insane deal on the RB26 rods and pistons. I've heard conflicting answers and want to make sure.

I apologize if this has been discussed. I've searched on Google and a could other sites and can't find a definite answer. Thank you for those willing to help me.

[ARA300ZX]

Ok. So from what I have gathered, I'd need to use the RB26 crank with the 26 pistons or the 25 crank with 25 pistons. I cannot use the 25 crank wit 26 pistons because the 26 pistons have a lower deck height which would cause me to run a very low compression.

[Koukiii]

I believe the rb26 and 25 rods are interchangeable. The rb25 neo comes with rb26 rods so they say.

If you building from scratch some eagle rods and rb25 aftermarket pistons will be your best bet. Coupled with rb25 crank and your good to go.

[ARA300ZX]

I'm trying to build on a somewhat budget. Not trying to go insane like in did on my VG. I can get a great price on the 26 pistons and rods. From what I've been told if I use the 25 crank with 26 pistons, it will lower the compression... So if the compression is lower, doesn't that mean I can up the boost?

[AS240]

It really depends on what power you plan on making. The weak points on a 25 are going to be the piston ring lands and the oil pump drive on the crank. If you plan on having everything apart and having machine work done, you really need to get a crank collar put on, especially if you plan on making decent power. 26 rods, 25 crank with a collar, and some basic forged pistons like supertech or wiseco will be a reliable setup that could handle power in the 600hp range. If you have extra funds, get a set of poncams. For some reason, rbs tend to break cams....I don't know if its improper installation or bad casting techniques but it seems to be a frequent occurrence as of lately .

[ARA300ZX]

My buddy is pretty much giving my the RB26 rods and pistons. I've been told the 26 rods are stronger. I don't want to start going crazy like I did with the VG because then it will become another 10 year project (literally).
I'm not looking for dyno queen numbers and my Z32 will have 600+rwhp. I just want a responsive RB with 4-500hp. If the 26 pistons are going to hinder performance, then I'll begin my search for 25 pistons.

[ARA300ZX]

OK so good news, the guy who I was buying the RB25 crack is going to refund me and I will just get RB26 crank. Noob mistake and rushed into it. Lesson learned.

[fatduece]

Was the crack not to your liking? I'd turn him in.

[smoked240]

For the rotating assembly, keep the crank and pistons matched. The piston height is different between the two an they correlate with their crank.

Extended crank collar, arp head studs and some upgraded pistons and you'll clear 500hp safely all day with supporting mods.