Head Pistons Knees and Toes!

Rohan I am informed that its not just the 32 mm over ports in Combat CHO head but also their more severe turn of the ports that helps stifle them, so must account for port shape changes in 850's 32 mm ports. I don't know about 850 heads though just what my builder told me. Big ports and big cam come into play near top end which is rarely what we want or need in real life. Generally smallish ports that only begin to choke up "after" red line limit would be best all around.

You may recall that when all the racers heard of the fullauto heads project, they all to a man requested that maybe thought could be given to raising the inlet port a 1/2", to give more downdraft.
Unfortunately, this would have made the heads incompatible with road bike fitment, so wasn't done...

If Amals had made a suitable downdraft carb, not sidedraft, who knows what may have appeared and eventuated on Commandos back then...