I have always wondered if a water cooled engine can be made with the cylinder and head integral like you see on many air-cooled engines. I was curious if one could machine coolant passages through the side of the cylinder and then through the head. I am sure screw in “plugs” would have to be used in the head to block of passages required for such machining through the head.
Would such a design be possible? IF possible, would it simply be too costly or limit the cooling capacity of the engine? I figured it might benefit from not having a head gasket, maybe allowing for hotter and more efficient running? OHV operation has been done on the air-cooled version via pushrods, timing chains, and belts. Has such an engine ever been made in the water cooled variety? I figure the benefits (if possible) might not be balanced out by the costs.
Any opinions or firsthand experience?