This special had more than its share of troubles, it was a very difficult birth. Once the correctly programed Power Arc showed up the bike ran. The modified Boyer ignition is just not up to running a 270. The bike FINALLY ran, the pistons were pistoning, the valves were valving, and all those funny bits in there were rotating. Unfortunately the head gasket was not gasketing. Clearly there is more to this annealing process. Got a replacement from Gaskets Unlimited and installed it after doing the annealing treatment - carefully.
On this bike it is not possible to just pull the head, it is major surgery, removal of the primary, transmission and engine to get the head off.
The replacement gasket was installed and everything reassembled. Finally it runs. (notice I get the bike running in time for winter storage)
Vibration Levels
I was not expected turbine smooth, and in fairness I have ridden a rubber mounted 270 and did not feel any vibration. This solidly mounted engine does buzz. I can ride the bike for a maximum of two hours in a stretch. It seems the vibration is different than a solidly mounted 360 and occurs at different revs. There is less in the pegs and the seat but more in the handlebars, and it does get smoother the faster it goes. It has not been wide open yet so I do not know about vibration levels over 5K.
Performance
These 270's are very quick to rev up so it is quicker off the line and through the gears. This engine configuration is happiest at freeway speeds. However, my riding style is that I like to plonk along back country roads pulling 2k at forty to 50 mph which this engine does not like to do. I am sure it would be happier on the racetrack than on the street.
Anyway it is off to the Dyno to determine the best engine settings.