@Tom Tee posted:...One of the trade offs in rod length is the way a short rod promotes piston skirt wear/cylinder scuffing and a long rod reduces piston skirt wear/cylinder wall scuffing...would you have cylinder maintenance comments concerning comparative rod lengths?
Making this comparison is a bit of apples and oranges.
In a gasoline or diesel engine, the connecting rods are directly attached to the piston via their connection at the wrist pin. Therefore, any angularity in the connecting rod is transmitted directly to the piston and to the cylinder walls. The resulting scuffing with short connecting rods is a direct result of this angular force imparted to the piston.
In a steam locomotive, the crosshead assembly sits between the main rod and the piston/cylinder. All of the angular forces from the main rod are absorbed by the crosshead. The piston rod always moves in a straight line with the piston and the cylinder, thus there is no additional wear in the cylinder when a short main rod is used.
I can see where there may be some additional stresses and wear in the crosshead with a short main rod, but I don't have any specific data to confirm that.
