rb25 heads on rb30

[Aiden88vl]

hey guys, i have a 88 vl non turbo and have heard a few things about putting (as the title says) a rb25 head on a rb30 block. what's the difference in doing so, is it just bolt on, and most importantly is it even worth it?... also, what other bolt on mods will go nicely? currently have larger fuel rails and injectors, high performance leads and plugs, cold air intake, and 2 1/2 inch exhaust and hollow cat.
cheers.. and feedback will be greatly appreciated.

 

[Jxfwsf]

http://rb30det.info/attachments/049_RB30_DOHC.pdf fair bit of work involved, yes it would be worth it even in na form, dohc, 24 valves.

 

[Aiden88vl]

thanks mate, what about the rb25det and rb25de? any difference in the heads and compatibility?

 

[Jxfwsf]

read the pdf i linked it has a lot of info regarding heads, pistons, oil pumps etc and what needs to be done.

Compatible DOHC Heads
Three heads can be used for the twin cam conversion.
•
RB26DETT Head
•
RB25DE (R32) Head
•
RB25DE/T (R33) VCT Head
All three heads cc up around the 62-64cc mark.
However, please be sure to double check, there have been cases where people have bought heads that for some reason are way off. Possibly aftermarket.
As a reference point the RB30’s SOHC head cc’s up around the 55 to 58cc mark.
The RB26DETT head from the R32/33 GTR bolts only requires a modification to the head stud holes.
The RB26DETT runs larger studs. All water/oil galleys line up.
The R32 RB25DE head bolts straight up to the RB30E bottom end. All water/oil galleys line up.
N/A valve springs have less tension which may cause issues when running big boost.
Cams and springs are interchangeable with RB20DET items.
The R33 RB25DE/T has variable cam timing (VCT/NVCS); this requires welding of the heads VCT oil feed.
The head still requires oil to its VCT, you will have to tap in to the oil galley and run an oil feed to it. The most common used feed is T’ing into the oil pressure sender feed.
Compare the pictures below to gain an understanding of how the head needs to be modified.

 

[Aiden88vl]

thanks mate

 

[HERONVY]

id go the 26 head ;-)

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[nasty1]

wouldn't bother would be a waste of a few thousand unless your hanging a turbo on the side.

best of to to do a turbo conversion....