Best compression ratio neccesary for .420 cams

Hmm, lots of good info here- looks like I may be porting some heads here soon, with someone that really knows these engines and has done hundreds of Z1 heads before.

I have ported heads before- just not Kawi heads.

So what is the power band on the 410 and the 420 cams? with 1000cc's and ported heads and 10.5 to 1 compression pistons?

I want to get a good baseline tune with carbs before I jump to EFI, and I want the motor to be done!

I had rc400 .424 lift 260 duration @.050" cams last year(similar to web #109) and they pulled harder at 7000rpms .i now have a web cam similar to the ape k410 but a little broader all around.it is.415" lift 252* dur @ .050" (web grind #493). i find there isnt a big dif between the 2. but i dont feel the pull at 7000 rpm any more. it is more even all around.see sig bellow for bike specs. 10.25:1 wiscoes with 155 psi compression.

BSKZ650 wrote:

compression ratio is a factor from volume of the head (cc,s ) and the dome of the piston, the valve overlap can play a small part but the tighter the chamber the higher the comp ratio.
I dont think I have ever installed a cam that made any real changes in the compression ratio, and changing the degree of the cam made no differance either, but it does make the motor respond

sorry sleep walking again.