0316449 EVINRUDE SUPPORT, Bracket to head

Pistons, Rings And Connecting Rods
The steel pistons have three rings, two compression rings and one oil ring. All rings are located above the piston pin bore. The seat for the rings is an iron band that is cast into the piston. The action of the rings in the piston groove, helps prevent seizure of the rings caused by too much carbon deposits. The oil ring is a standard (conventional) type. Oil returns to the crankcase through holes in the oil ring groove. The piston pin is held in place by two snap rings that fit in grooves in the pin bore of the piston.The connecting rod has a taper on the pin bore end. This taper gives the rod and the piston more strength in the areas with the most load.Oil spray tubes, located on the cylinder block main webs, direct oil to cool, and give lubrication to the piston components and cylinder walls.Crankshaft
The crankshaft changes the combustion forces in the cylinder into usable rotating torque which powers the machine. Vibration, caused by combustion impacts along the crankshaft, is kept small by a vibration damper on the front of the crankshaft.The crankshaft drives a group of gears (front gear train) on the front of the engine. The front gear train provides power for the following components: timing gears and oil pump. Seals and wear sleeves are used at both ends of the crankshaft for easy replacement and a reduction of maintenance cost. Pressurized oil is supplied to all bearing surfaces through drilled holes in the cylinder block. The oil then flows through drilled holes in the crankshaft in order to provide oil to the connecting rod bearings. The crankshaft of the engine is held in place by five main bearings. A thrust plate at either side of the center main bearing controls the end play of the crankshaft.Camshaft
The engine has a single camshaft that is driven at the front end. The camshaft is supported by five bearings. As the camshaft turns, the camshaft lobes move a lifter assembly. As the camshaft turns, each camshaft lobe, through the action of valve systems components, moves either two inlet or exhaust valves for each cylinder. The camshaft must be in time with the crankshaft. The relation of the camshaft lobes to the crankshaft position causes the valves and injectors in each cylinder to operate at the correct time.Vibration Damper
Illustration 1 g03063636
371-9382 Damper and Pulley Gp
(1) 167-8130 Damper
(2) 374-2522 Crankshaft Pulley
(3) 4N-2109 Damper Adapter
(4) 6N-7654 Spacer The force from combustion in the cylinders and from driveline components will cause the crankshaft to twist. The crankshaft twist is called torsional vibration. If the vibration is too great, the crankshaft will be damaged. Driveline components can excite torsional stress. This stress can damage the components. The vibration damper limits the torsional vibrations to an acceptable amount in order to prevent damage to the crankshaft. The viscous vibration damper is installed on the front of the crankshaft. The viscous vibration damper has a weight in a case. The space between the weight and the case is filled with a viscous fluid. The weight moves in the case in order to limit the torsional vibration.