Where does the oil pump and the additional manual pump at higher speed that they talked about in the video go to. I was thinking maybe like a 2 stroke Kawasaki I had once that had the gas tank and two stroke oil in separate tanks. There was a pump that sent oil into the cylinder as a spray or something.
I know in the video helping Jay Leno, the guy said if you see blue smoke out the exhaust it is happy, then you have pumped it enough.
MT these old 4 cycle engines were total loss oil systems that relied on constant drip from a separate oil tank to lubricate the two rings cylinder (the lack of a third ring was explained in the video) and bottom end and excess oil went out the exhaust system. The drip oil was not mixed with the gas or run through the carb, blue smoke was caused by excess oil reaching the combustion chamber being burnt off. The engine in the Leno video was a side valve design 4 cycle that indeed had two tanks one for oil and one for gas, but didn't function in any way similar to a 2 cycle...just used two tanks. Rick C.
I thought about it too when if it were a two stroke, there could be a pressure relief valve, but no rocker, as those are for intake exhaust. The exhaust valve may have on this one just been held open as pressure relief as I heard said out the exhaust.
Visually the ports of two stroke engines are not atop the cylinder but sort of midway also.
The only time I heard of no sump oil in a 4 stroke, was some guys video that he put together two Briggs and Stratton engines with 1 head in the center. The two compression strokes had the two pistons make twice the compression. And believe it or not, they guy I guess for some reason did not figure the oil bath and for a short while ran with grease smeared inside the crankcase for short maybe 3 minute run time and shut it down after that. Strange?