22ci & 44ci Twins - Oil Lines Work How?

[itstippy]

Reading an earlier post made me wonder how the "oil lines" on my twins from the 60's work. The lines run from the lower case (by the bottom crank bearing) to the upper case (by the upper crank bearing). Books say they take oil/gas that's puddling in the bottom of the case and recirculate it to the top. Uphill without check valves. How?

 

[CFronzek]

Re: 22ci & 44ci Twins - Oil Lines Work How?

This is a guess but it's not hard to imagine using the pressure/vacuum pulsations generated by the pistons going up and down to cause a pumping action. Because these motors are alternate firing twins the one crankcase has pressure while the other is sucking. <br />On Kawasaki motorcycles with a rotory valve there was the possibility of gasoline puddling in the chamber where the carb was housed. The answer was a small diaphram pump that worked off crankcase pulsations. The shortcoming was the diaphram would rupture unexpectedly killing the motor. If you knew what the problem was you could drive a wooden plug thru' the diaphram and get the bike to fire.