PIN 3680477 - Caterpillar

Cylinder Head and Block
The cylinder head assembly has one inlet valve and one exhaust valve for each cylinder. Each valve has a single valve spring and a valve seal. The valve and the valve spring are held in position by a valve spring retainer and two collets. The valve seal fits over the top of the valve guide. The valve guides can be replaced.The ports for the inlet and for the exhaust valves are on the left side of the cylinder head.The cylinder block does not have cylinder liners. The cylinder walls are honed.The valve mechanism cover is made from aluminum. The cover contains the following components:
A closed breather assembly
An oil filler cap
A seal for the face toward the cylinder head
Holes for four cap nuts
Holes for two bolts
An air inlet manifoldThe cap nuts are threaded onto studs. The steel studs are threaded into the cylinder head.The bolts are threaded onto the cover for the rocker shaft assembly.The valve mechanism cover contains a closed breather assembly. The gases in the valve cover, which are caused by blowby, pass from the crankcase to the inlet manifold.Pistons and Connecting Rods
The pistons of the engine have a combustion chamber in the crown of the piston in order to provide an efficient mix of the fuel and the air.The piston pin is off-center in order to reduce the noise level.The pistons have two compression rings and an oil control ring.The correct piston height is important in order to ensure that the piston does not contact the cylinder head. The correct piston height also ensures the efficient combustion of fuel which is necessary in order to conform to requirements for emissions. The piston must not be machined in order to obtain the correct piston height.A piston and connecting rod are matched to each cylinder.One height of piston is available. The inside of the piston is marked "Shibaura". This reference mark faces the right side of the engine. Refer to Testing and Adjusting, "Piston Height - Inspect" for procedures to measure the piston height.Identification marks on the connecting rod and the connecting rod cap must align. The identification marks face the right side of the engine.The main bearing caps have a chamfered edge on one side. The chamfer faces the front of the engine.Timing Gear Case and Gears
The timing gear case contains the following components:
Front oil seal for the crankshaft pulley
Bearing for the crankshaft gear
Engine oil pump
Adjustment screw for setting the maximum fuel position
Adjustment screw for setting the maximum speed position
Mechanical stop control
Linkage for the fuel injection pump
Fuel Control lever for the governor
ThrottleThe crankshaft has a front bearing that is pressed in the cylinder block and three main journal bearings on three cylinder engines and four main journal bearings on four cylinder engines.The thrust washers are hemispherical in shape. A third thrust washer is located on the rear side of the upper half of the holder for the rear main bearing.The crankshaft has a front oil seal and a rear oil seal.The timing case is