It has been pointed out that my Comet , it not being a complete nail, could have a bit more get up and go so I have been reading around the subject and have a couple of initial questions.
was it common with all British m/c manufacturers to use vague timing marks on their gears sufficient for starting and road riding, why not use accurate timing marks at point of assembly or was this a compromise allowing for use of different cam profiles.
My next query may possibly be due to introducing confusion by comparing notes on parallel twin valve timing with Vincent valve timing. Bruce Metcalf on Vincent.Com noted that when considering valve timing ;
" split the overlap at TDC at .050" lift. This means if intake opening is at 0 deg and exhaust closing is at X deg, make the intake opening at 0 + X/2 deg. Then you can retard that for more peak power or advance it for more low down torque".
Is this saying the same thing as when considering parallel twin valve timing and trying to achieve manufacturers specified amount of lift at X deg and where this can't be achieved to the degree, better to err on the inlet opening early than the exhaust closing late.
was it common with all British m/c manufacturers to use vague timing marks on their gears sufficient for starting and road riding, why not use accurate timing marks at point of assembly or was this a compromise allowing for use of different cam profiles.
My next query may possibly be due to introducing confusion by comparing notes on parallel twin valve timing with Vincent valve timing. Bruce Metcalf on Vincent.Com noted that when considering valve timing ;
" split the overlap at TDC at .050" lift. This means if intake opening is at 0 deg and exhaust closing is at X deg, make the intake opening at 0 + X/2 deg. Then you can retard that for more peak power or advance it for more low down torque".
Is this saying the same thing as when considering parallel twin valve timing and trying to achieve manufacturers specified amount of lift at X deg and where this can't be achieved to the degree, better to err on the inlet opening early than the exhaust closing late.