Sockmonkey
Well-Known Member
So, a while back I posted this guy.
A three-cylinder air cooled radial diesel two-stroke. Kept it to only three cylinders so it could have stroke overlap while using nested forked con rods to prevent the off-axis thrust and balance issues radials using a master rod have.
There was a potential issue with lubricating the rings without losing oil as it's meant to have four-stroke type crankcase lubrication with no oil mixed with the fuel.
Putting oil channels running up the crosshead rod to radial channels in the piston head that open out between the piston rings solves the piston lubrication issue and helps cool the piston.
Preventing leakage was done by getting rid of the side bulge transfer ports in favor of a central piston valve covering a ring of holes in the piston head, allowing the fresh air charge into the top chamber of the cylinder. As it's a two-stroke, the valve cam can be right on the crank, and one cam lobe can actuate all three piston valves. The overhead exhaust valves will still need rockers and lifters, but that's not too bad as we still don't need a separate camshaft.
I think everything is covered.
Anyone spot anything I missed?
A three-cylinder air cooled radial diesel two-stroke. Kept it to only three cylinders so it could have stroke overlap while using nested forked con rods to prevent the off-axis thrust and balance issues radials using a master rod have.
There was a potential issue with lubricating the rings without losing oil as it's meant to have four-stroke type crankcase lubrication with no oil mixed with the fuel.
Putting oil channels running up the crosshead rod to radial channels in the piston head that open out between the piston rings solves the piston lubrication issue and helps cool the piston.
Preventing leakage was done by getting rid of the side bulge transfer ports in favor of a central piston valve covering a ring of holes in the piston head, allowing the fresh air charge into the top chamber of the cylinder. As it's a two-stroke, the valve cam can be right on the crank, and one cam lobe can actuate all three piston valves. The overhead exhaust valves will still need rockers and lifters, but that's not too bad as we still don't need a separate camshaft.
I think everything is covered.
Anyone spot anything I missed?