sentences:  When the V-4 ran successfully, it seems they used four such engines connected to a common crankcase to produce the Hydra.The cams were operated by rotating shafts leading from the crankshaft at the back of the engine to the top of each cylinder row.The shaft was directly geared to one of the two camshafts, using another driven shaft to transmit power to the second camshaft on the "other side" of the cylinder heads.