80423M Mariner PISTON RING SET (1ST O.S. 51.25MM)...

Cylinder Head Assembly
The cylinder head is a one-piece cast iron head. The cylinder head supports the camshaft. Steel reinforced bearings are pressed into each bore. The bearings are lubricated under pressure. Bridge dowels have been eliminated as the valve train uses floating valve bridges.Thermal efficiency is enhanced by the use of stainless steel thermal sleeves in each exhaust port. The sleeves reduce the amount of heat rejection to the cooling system. The sleeves then transfer the thermal energy to the turbocharger.The unit injector is mounted in a stainless steel adapter. This adapter has been pressed into the cylinder head injector bore.Pistons, Rings And Connecting Rods
The piston is a two-piece articulated design that consists of a forged steel crown and a cast aluminum skirt. Both parts are retained by the piston pin to the small end of the connecting rod. The pistons have three rings that are located in grooves in the steel crown. These rings seal the combustion gas. The rings provide control of the oil. The top ring has a barrel face. This ring is a Keystone ring with a plasma face coating. The second ring has a tapered face and the ring has a coating of chrome finish for the face. The third ring is the oil ring. The third ring has a coil spring expander. There are four holes that are drilled from the piston oil ring groove to the interior of the piston. These holes drain excess oil from the oil ring.The connecting rod is a conventional design. The cap of the connecting rod is attached to the shank by two bolts that are threaded into the shank. Each side of the small end of the connecting rod is machined at an angle of 12 degrees in order to fit within the piston cavity.Crankshaft
The crankshaft converts the combustion force in the cylinder into rotating torque. A vibration damper is used at the front of the crankshaft in order to reduce the torsional vibrations.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: camshaft, water pump, oil pump, fuel transfer pump and accessory items that are specific to the application.The cylinder block has seven main bearings that support the crankshaft. The cylinder block uses two bolts to hold each of the bearing caps to the block.The crankcase uses a lip seal at both ends of the crankshaft.Camshaft
The camshaft has three lobes at each cylinder. These lobes allow the camshaft to operate the unit injector, the exhaust valves, and the inlet valves. The camshaft is supported in the cylinder head by seven journals which are fit with bearings. The camshaft gear contains integral roller dampers that counteract the torsional vibrations that are generated by the high fuel pressure during fuel injector operation. The design reduces gear train noise. The camshaft is driven by an adjustable idler gear which is turned by a fixed idler gear which is turned by a cluster idler gear in the front gear train. Each bearing journal is lubricated from the oil manifold in the cylinder head. A thrust plate that is located at the front controls the end play of the camshaft. Timing of the camshaft is accomplished by aligning marks on the crankshaft gear and idler gear, and camshaft gear with a mark on the front timing plate.