What Cams?

[...Joshwa]

Hi all,

Im at the final stage of building my RB30/25. .

I was going to use the RB25DE pistons however shaving 2mm off the block equates to a 4% loss in torque (Torque= Force x Distance). . and being an N/A I want all the torque I can get

I have opted to get a set of custom Hyper Eutectic pistons made, that way I can get valve notches cut into them and bore the block 30thou oversize. .

Bottom end is a linished crank, spool rods with arp rod bolts, hyper eutectic pistons, acl race series bearings for both big end and mains. .

This is all fully balanced with the flywheel and pressure plate. .

The head is a R33 head with VCT (Not sure if it can be used with custom cams?).. I am having it serviced and then when it is serviced I am going to have it re assembled with stiffer valve springs (if needed, not sure yet) to suit the cams. . Hopefully in the 270degree and 10mm lift range. .

So my main question is. .

What spec cams should I get? I understand that lift is for torque?? and duration is for. . . .? Note: I do not want to convert to solid lifters.

And then, my head is going to cc in at about 50cc, in the hope to get into the 11:1 comp range. . If I have cams with say a 10mm lift, how deep will the valve notches have to be to clear the pistons (0 deck height)??

Thanks all,

Josh