Rb25 Head On Rb26 Bottom End

[Gta51]

Hey guys

Blew the bottom end on my rb25 and a rb26 forged one came up for a good price. Just wondering if the rb25 head would bolt upto the 26 bottom just like if it was a normal rb25 ? Rb25 heads a s2 r33 one.

Cheers

[r32-25t]

Need to so the same modifications to the head as if you were bolting it to an rb30, it would also lower the compression ratio a little

[89CAL]

Would lose VCT, unless you were willing to play with external feeds etc. Also the 26 block uses bigger head studs from memory.

It sounds like a waste of time to me sorry. I know the idea of forged internals sounds great, but it's probably not worth it in the long run

What HP are you running? If its anything around or below 300rwkw, it would be cheaper and much easier to get a 25 block. Even do that, get it honed, new rings and some ARP main studs etc will make it a fairly strong RB

[Ben C34]

Cal nailed it.

The holes are tapped larger than rb25 . You would have to drill out the head studs holes.

[Gta51]

Car was pushing 370-380rwkw. Going for 420-430rwkw now so need a built donk .

Going forged with my block just thought I would get this since it was ready to go I guess.

[89CAL]

Do it yourself. That way you KNOW its been done right. I dont know how many cases ive seen of people getting engines built and then something goes wrong because the apprentice helped put it together and didnt do something properly etc. I built my engine and have not had a single problem

Its the more expensive option in this case but personally id rather spend the money and get it done right

[r32-25t]

You'd be better off bolting it to a built rb30

[ido09s]

or getting an RB26 head for the block

[Scando]

If the pistons in the RB26 block are for a larger than standard bore and if your RB25 block is still ok then you could get the RB25 block bored and put the RB26 crank, rods and pistons into your RB25 block.