@o0norton0o
My comment was purely on a informing base and not to be understood as a critic.
Im not working on commandos on a regular bases, but i think i remember that there would be still some space inbetween the bore to enlarge the bores about a 2,5mm's towards each other, not considering the crankshaft.
imho the power crucial point lies mostly in straightening the ports upwards and inclining them even further towards vertical and stuffing in the biggest valves by reinclining the guide bores. imho ovalizing the port area like on the XR750 could be adressed at a later point as i'm submit to eye cancer every time i see that already pretty in comparison to eg triumph's (in particular the trident is imho a nightmare) intake port and then that ridiculous manifold elbow subjecting all the design efforts on the intake port to mediocracy.
Im amazed nobody ever mounted some Fcr's / Tmr's or at least some independent float bowl carbs and went straight outta the door without that friggin redundant ellbow.
i explicitly dont mean this as an offense to the commando type engine but these thoughts occure to my mind.
@ acotrel
thanks for the info regarding the AJS.
regarding pattoni:
the patoni500 was designed as a pure race breed race engine therefore in my opinion comparison with road engine designs are not legit, in particular regarding the fact that at least as i assume that most of the brit companies were at that time already severly low on funds or will to go to war in designing a bad ass engine.
Considering that the kawa twin is somewhat similar to the pattoni500 one can wonder why the mount them on their new road bikes.
Concerning your multi variable concern regarding head design i will try later to emphasize on my thoughts/ approach to head porting, but rest assured that i think that the commando intake ports could be still inclined a further approx 5 degrees (see also my thoughts above)which is in terms of turbulence and thus higher flow numbers with smaller flow areas therefore higher velocity of flow.
Regarding the 4 valve commando:
for the interested i think one of those watercooled norton engines was years and years ago in the property of britalia motors in santa cruz and in exposition there.
kind regards
Christian