(1) I meant put a flywheel on in place of a prop and run one at 18,000 plus..........and see what happens...........

(2) I'll bet your modern marine engines have very light pistons, massive blocks, and heavily counterbalanced crankshafts............

(3) Even people like Cox got it wrong from time to time-the TD15 and it's successors were notorious for vibration in their day when propped for peak revs-'shake timers to bits' was the expression used by some of my older mentors who did use them. The answer was to grind both flanks of the crankweb carefully to increase the degree of counterbalancing. The magic figure-according to the books, is balancing 60% of the reciprocating weight..........

(4) OS went to the extent of using counterbalanced prop drivers for a while in the 1960s on the Max-15 and 19-did it work? I don't know-they stopped doing it........

(5) Anyone remember the famous K&B 45 greenhead-arguably the first 'proper' pattern engine? It had a backplate mounted counterbalance driven from the crankshaft to improve smooth running

(6) The russians-no fools when it comes to miniature IC engine design-even went as far as drilling holes axially around the circumference of part of the shaft to counterbalance the weight lost from the intake cutout.........and this was in a cheap F2D training motor.....the Typhoon.


....as for me, all I will say on the flywheel aspect is that I have several engines fitted with heavy brass spinner nuts for CG purposes-(and one is your beloved PAW19 DS!)-and these engines seem to start easier and run smoother than those without-but I've never systematically looked into it.

ChrisM
'ffkiwi'