3R3-62445-0 Nissan BOLT, CO-PILOT

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 an oil seal. The valve and the valve spring are held in position by a valve spring cap and two retainers. The oil seal fits over the top of the valve guide. The valve seat inserts and the valve guides can be replaced.The ports for the inlet valves are on the right side of the cylinder head. The ports for the exhaust valves are on the left side of the engine.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:
Closed breather assembly
Breather hose
Oil filler cap
Seal between the valve mechanism cover and the cylinder head
Holes for three cap nutsThe cap nuts fit onto studs on brackets. The brackets are mounted on the cylinder head.The gases in the valve cover, which are caused by blowby, pass from the breather assembly through the breather hose into the inlet manifold.Pistons and Connecting Rods
The pistons have a combustion chamber in the top 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. The piston height is controlled by the length of the connecting rod. Three lengths of connecting rods are available in order to attain the correct piston height. The different lengths of connecting rods are made by machining the small end bearing off-center in order to form an eccentric bearing. The amount of the eccentricity of the bearing creates the different lengths of the connecting rods.One height of piston is available. The piston is marked "Std" on the crown. Refer to Testing and Adjusting, "Connecting Rod - Inspect".On a new engine, the cylinder number is etched on the left side of the connecting rod and the cap. The letter that indicates the grade for the connecting rod is also etched on the left side. The letter that is etched on the right side of the connecting rod is the reference number of the manufacturer. The part number on the connecting rod should be toward the front of the engine. Location marks for the main bearings are toward the right side of the engine.Timing Gears, Crankshaft, and Camshafts
The timing case contains the following components:
Front oil seal for the crankshaft pulley
Bearing for the crankshaft gear
Engine oil pump
Engine oil relief valve
Adjustment screw for setting the maximum fuel position
Linkage for the fuel injection pumpThe crankshaft has five main journal bearings. These bearings are made of steel with an alloy of aluminum and tin on the face. End play of the crankshaft is controlled by two thrust washers. The thrust washers are located on both sides of the number four main bearing.The crankshaft has a front oil seal and a rear oil seal. The oil seals include a dust lip which is on the outside face of the seal. The oil seals have grooves on the face of the main lip for oil return.The timing case is made of aluminum. The timing gears are stamped with timing marks in order to ensure the correct assembly of the gears. The mark on the crankshaft pulley is aligned with the mark on the timing case when the No. 1 piston is at the top center position on the compression stroke. The crankshaft gear turns the idler gear which then turns the following gears:
Camshaft gear for the valves
Camshaft gear for the fuel injection pumpAlso, the crankshaft gear turns the gear of the engine oil pump.The crankshaft pulley drives the pulley on the water pump and the pulley on the alternator. A drive belt connects the three pulleys.Both camshafts rotate at half the rpm of the crankshaft.Fuel System
The 3034 engine has an Energize-To-Run (ETR) system for starting the engine and stopping the engine. The fuel shutoff solenoid must be energized in order for fuel to flow to the engine cylinders.The fuel injection pump fits directly into the cylinder block. The fuel rack, the plungers, and the barrels are inside of the fuel injection pump.The plungers are driven by a camshaft.The fuel rack is connected to a linkage that controls the fuel injection pump. This linkage is located in the timing case.The governor weight assembly is installed on the front of the gear of the camshaft for the fuel injection pump.The fuel injection pump timing, the low idle, and the high idle are preset at the factory. Adjustments to the pump timing and idle rpm should only be made by trained personnel. The timing for the fuel injection pump should only change if the camshaft for the fuel injection pump or the cylinder block are replaced. If the shim in the fuel injection pump is not changed, the timing of the fuel injection pump should not change. The fuel shutoff solenoid is mounted to the cylinder block at the rear of the fuel injection pump. The plunger of the solenoid operates on the rack of the fuel pump. When the fuel shutoff solenoid is energized, the fuel rack is in the RUN position.An identification plate is mounted on the front of the fuel injection pump. The identification plate contains the following information:part number and code letters.The camshaft gear for the fuel injection pump has a mechanical governor in order to control the engine rpm.The fuel injection nozzle operates in two stages. The first stage injects fuel into the cylinder at a set pressure. The second stage injects an additional