You guys are going to like this vid, classic engine start ups...

[A.K. Boomer]

The lower crankshaft leads the upper by 12 degrees for exhaust scavenging, it also produces about 75% of the total output.

Unusual statement, since both pistons appear to be the same size and are under identical pressures, so is the lower crank stroked quite a bit more?

[CarlByrns]

That's according to FM. I have no idea how they arrived at that number.

[Doozer]

Strange engine, you could see with ports that low if there was a way to have fingers in there it would not take any rotational effort at all to sever them that's a very high leverage ratio for crank rotational degree's compared to piston movement...

So the danger of an extremely unlikely scenario to remove ones fingers is what comes immediately to the forefront of your mind?
You do realize this engine is like 15 feet tall ??? I have personally had my hands on a running F-M engine like this, and staying
away from the spinning flywheel spokes was in the front of my mind. This particular engine had zoomie style headers and there
was not even a chance of getting near the piston ports. You may either be afraid of everything or afraid of the wrong things.

-D

[A.K. Boomer]

So the danger of an extremely unlikely scenario to remove ones fingers is what comes immediately to the forefront of your mind?
You do realize this engine is like 15 feet tall ??? I have personally had my hands on a running F-M engine like this, and staying
away from the spinning flywheel spokes was in the front of my mind. This particular engine had zoomie style headers and there
was not even a chance of getting near the piston ports. You may either be afraid of everything or afraid of the wrong things.

-D

Lol nah Dooze was just putting the past scene of the crime together on how the old man lost two of his --- get out of your fetal tuck, everythings going to be ok...

[A.K. Boomer]

That's according to FM. I have no idea how they arrived at that number.

I just looked at specs real quick and looks like it's identical stroke for upper and lower pistons/crank throws, Kinda makes sense for not upsetting the balance but that only leaves one explanation, the 12 degree's advancement favors the lower cranks optimum rod angle/piston speed during burn rate, still 75% would be a substantial boost from just that,

but really all I can come up with - for now anyways...

[Doozer]

Lol nah Dooze was just putting the past scene of the crime together on how the old man lost two of his --- get out of your fetal tuck, everythings going to be ok...

I am outside in the real world running engines.
You are dreaming of danger from your chair posting on the internet.
Who is in a fetal tuck exactly?

-D

[A.K. Boomer]

I am outside in the real world running engines.
You are dreaming of danger from your chair posting on the internet.
Who is in a fetal tuck exactly?

-D

Oh wow so now you have more engine experience than I do? your not only in a fetal tuck --- your fuquing dreaming...

Stop freaking out about trying to figure out how a guy got his fingers severed --- it will be ok - there's people you can talk too to make you feel better...