Need some head... - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

Wanabee Kiwi · 16th July 2008, 08:20 AM

...advice

Are RB26 and RB25 Heads the same casting? I've heard they are but not from a reputable source... wondering if someone in the know could let me know

tokes · 16th July 2008, 09:02 AM

No. RB25's have 10mm head bolts, RB26 is 12mm.

RB25 has a 66.5cc combustion chamber, RB26 is 70cc's

The valvetrain is also radically different.

R.I.P.S NZ · 16th July 2008, 09:04 AM

Totally different heads.

Tokes: fyi, the 25s use 11mm head bolts

tokes · 16th July 2008, 09:25 AM

Interesting.

Do the RB20 and RB25 share the same headbolt diameter? I've never mucked about with either of the smaller motors, but was under the impression that they were both 10mm.

R.I.P.S NZ · 16th July 2008, 08:49 PM

I'm 99% sure the RB20 is the same as the 25, but the 25 and 30 are definatly 11mm.

Rob

Wanabee Kiwi · 17th July 2008, 08:36 AM

Mint cheers. RB26 it is then

Rob what sort of price should I be paying for a decent 26 head, there's trademe specials but i'm not convinced that $3000 is a good price.....

tokes · 17th July 2008, 10:51 AM

Quote:

Originally Posted by R.I.P.S NZ

I'm 99% sure the RB20 is the same as the 25, but the 25 and 30 are definatly 11mm.

Rob

Thanks Rob!

16th July 2008, 08:20 AM	#1 (permalink)
Wanabee Kiwi GTR Register Member Join Date: Mar 2007 Location: Christchurch NZ / Oxfordshire Posts: 543	Need some head... ...advice Are RB26 and RB25 Heads the same casting? I've heard they are but not from a reputable source... wondering if someone in the know could let me know

16th July 2008, 09:04 AM	#3 (permalink)
R.I.P.S NZ GTR Register Member Join Date: May 2004 Location: Rotorua NZ Posts: 2,323	Totally different heads. Tokes: fyi, the 25s use 11mm head bolts __________________ R34 GTR: Quickest full street trim skyline in NZ, 9.7 @ 137 on 1st test pass, first meeting in the UK, 10.4 @ 144. RIPS 240z, WRH8.36 / 163 @ 1.9 bar, stock crank, stock block, petrol RIPS 240z, RIPS RB30, quickest/fastest Jap street car in NZ 8.36/163mph 1.9 bar. NZs quickest Pro Import on petrol. RB engine building, alloy and stainless fabrication, affordable skyline tuning and high capacity repowers, worldwide shipping arranged. e-mail rips@inspire.net.nz www.ripsracing.com

16th July 2008, 08:49 PM	#5 (permalink)
R.I.P.S NZ GTR Register Member Join Date: May 2004 Location: Rotorua NZ Posts: 2,323	I'm 99% sure the RB20 is the same as the 25, but the 25 and 30 are definatly 11mm. Rob __________________ R34 GTR: Quickest full street trim skyline in NZ, 9.7 @ 137 on 1st test pass, first meeting in the UK, 10.4 @ 144. RIPS 240z, WRH8.36 / 163 @ 1.9 bar, stock crank, stock block, petrol RIPS 240z, RIPS RB30, quickest/fastest Jap street car in NZ 8.36/163mph 1.9 bar. NZs quickest Pro Import on petrol. RB engine building, alloy and stainless fabrication, affordable skyline tuning and high capacity repowers, worldwide shipping arranged. e-mail rips@inspire.net.nz www.ripsracing.com

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16th July 2008, 09:02 AM	#2 (permalink)
tokes GTR Register Member Join Date: Jul 2006 Location: Canada Posts: 326	No. RB25's have 10mm head bolts, RB26 is 12mm. RB25 has a 66.5cc combustion chamber, RB26 is 70cc's The valvetrain is also radically different.

16th July 2008, 09:25 AM	#4 (permalink)
tokes GTR Register Member Join Date: Jul 2006 Location: Canada Posts: 326	Interesting. Do the RB20 and RB25 share the same headbolt diameter? I've never mucked about with either of the smaller motors, but was under the impression that they were both 10mm.

17th July 2008, 08:36 AM	#6 (permalink)
Wanabee Kiwi GTR Register Member Join Date: Mar 2007 Location: Christchurch NZ / Oxfordshire Posts: 543	Mint cheers. RB26 it is then Rob what sort of price should I be paying for a decent 26 head, there's trademe specials but i'm not convinced that $3000 is a good price.....