I'm working a few mods that virtually eliminate detonation and increase thermal efficiency. Since I need to pull the head/cyllinders off my '79 CB650, I figured it would be the perfect candidate for the work. My mods have allowed 10.5:1 without any detonation in similar combustion chambers and operating conditions. Just by examining pictures, it seems that the head won't allow much decking because the valves are so large. This means I'd have to deck the cyllinders, which would have the added benefit of moving the head closer to the pistons and creating somewhat of a squish ring around the outer edge of the pistons. For my mods to work, it is imperative that my engine has at least some squish in the chambers, so decking the jugs would be the most advantageous.
How much can the heads/jugs be decked without valve/piston contact with a stock cam on the 1979 CB650?
