RB26 and RB25 cam covers...

[Ronin 09]

Hi guys

Just a quick query with respect to cam covers… more for my own interest than considering doing the change...

In various Japanese publications, I have seen that many tuners replace the RB26 'buldge' type cam covers (with the breather pipes at the rear) with RB25 type slimmer cam covers… even the JGTC cars I've seen run with these smaller cam covers.

My contention is that this is done so that the breather pipes (on RB25 cam covers the breathers are near the centre of the covers, front-to-back) are closer to the front of the engine, and closer to where a catch can might be (ie drivers side front corner). Can anyone confirm this?

And, if so, do all the head bits clear the RB25 covers, or do they need to be clearanced? Do they even bolt up to the same locations on the head?

Cheers