# What's the difference between RB26 and RB25 cam cover hose



## XashskylineX (Jun 25, 2013)

Why are RB26 breather on top by cylinder 6 and RB25 by 2-3 ?


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## XashskylineX (Jun 25, 2013)




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## K66 SKY (Jan 25, 2005)

XashskylineX said:


> *Why are RB26 breather on top by cylinder 6 and RB25 by 2-3 ?*


I have no real idea why they have different locations but these two types have different diameters _(the RB26's is much bigger in size than the RB25's)_ too so it must be something to do with its function and the higher power output of the DETT twin turbo engine if you ask me?!


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## XashskylineX (Jun 25, 2013)

K66 SKY said:


> I have no real idea why they have different locations but these two types have different diameters _(the RB26's is much bigger in size than the RB25's)_ too so it must be something to do with its function and the higher power output of the DETT twin turbo engine if you ask me?!




I was thinking it's got to do with breathing ?


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## K66 SKY (Jan 25, 2005)

XashskylineX said:


> *I was thinking it's got to do with breathing ?*


Agreed! One turbo for the RB25 v's two turbo's on the RB26's....emissions regulations and engine reliability must also have something to do with it XashskylineX?!

I doubt Nissan's engineers do things by accident. When you look at the very basics and see the minute differences between these two RB coded engines....

_*2.5 L (2498 cc, bore: 86.0 mm, stroke: 71.7 mm) v's 2.6 L (2568 cc, bore: 86.0 mm, stroke: 73.7 mm)*_

and performance wise in standard form,

_*RB25DET - twin-cam SINGLE TURBO (250 HP and 319 Nm of Torque) v's RB26DETT - twin cam TWIN TURBO (276 HP and 392 Nm of Torque)....*_

These all add up to one requiring a slightly better engine oil breathing system than the other one. Sorry I cannot give you a definitive answer but it kinda makes sense to me.

HTH & JM2PW!


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## Simonh (May 24, 2002)

the top ends are quite different between the rb25 and the rb26, solid buckets, no VVT on the Rb26, different baffling IIRC on the cam covers and the greater traction from the 4wd on launch and cornering means the breather pipes need to be in a different place. You can fit the RB26 cam covers to the RB25 head with some minor adjustments I think.


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