How to measure the deck left on a RB26 Head.

[boostedh23a1]

I know on some of the domestics you can tell how much the head has been milled by measuring on a specific point on the head. Is there a way to do this on the RB26 head, I dont see anything about it in the engine manual.

[Carl H]

cc the combustion chamber, that against a known 'standard' value will tell you how much its been milled.

[boostedh23a1]

Yea I thought about that, just trying to do it on the spot before I buy some spare. 69cc is eom correct?

[Carl H]

i think thats right, i havent looked in a while.

[boostedh23a1]

My chamber volume is now 70.6cc after port and chamber work (left the quench pads, just cleaned up) what head gasket thickness should I look at? Block is a rb30 with flat top pistons on a to4z.

[boostedh23a1]

WELL F ME!...

Built a head now it has 70.6cc chamber volume and with the thinest headgastet (.8) thats only 7.51 compression on a rb30. That s*** isnt gonna work. f***.

[boostedh23a1]

does anyone have the part number for those cp pistons for the rb30 with 26 head that are 9:1 instead of the 8:2?
http://www.hioctanedirect.com/index.php ... cts_id=501

[Carl H]

http://www.cppistons.com/LinkClick.aspx ... d&tabid=82

[boostedh23a1]

those are all 8:2 just different Bore sizes.
The ones i am talking about are
p/n= CP-RB30/26-.20
Flat top with no valve pockets
8.2:1 compression with RB25 head and bit less with RB26 head
21mm pin
1.280" compression height
Only stocked in 0.20 thou oversize but can be custom ordered in any size.

p/n= CP-RB30/26-.20-9.0
6.0cc dome top,
9.0:1 compression with RB25 head and bit less with RB26 head
21mm pin
1.280" compression height
Only stocked in 0.20 thou oversize but can be custom ordered in any size.
*Care must be taken when using on RB26 with more than 11.5mm valve lift*

[Carl H]

call cp up and tell them what you want, they're usually pretty helpful.

[boostedh23a1]

Well i went with custom 9:1 which has a 6.7 dome on it. with the 70.6cc combustion chamber that should give me around a 8.3:1 with a .8 gasket.