401A0-ZV4-650ZB Honda CASE, OIL *NH282MU* (OYSTER SILVER METALLIC-U) (Honda Code 3744695).

Illustration 1 g03890746
Front side of the block
(1) Main oil gallery
(2) Camshaft oil gallery
(3) Piston cooling jet gallery
(4) Piston cooling jet gallery
(5) Camshaft oil gallery
(6) Sequence valveNote: There is a sequence valve (6) in both the front and rear of the block.
Illustration 2 g06325065
Right-hand side of the engine
(7) Turbocharger oil supply line
(8) Turbocharger oil drain line
(9) Engine oil cooler
(10) Engine oil pump
Illustration 3 g06325098
Right-hand side of the engine
(9) Engine oil cooler
(10) Engine oil pump
(11) Engine oil cooler bypass valve
(12) Engine oil pump relief valve
(13) Elbow
(14) Suction bellEngine oil pump (10) has three gears that are driven by the front gear train. The engine oil pump pulls engine oil from the pan through suction bell (14) and elbow (13). The suction bell has a screen to strain the engine oil.Relief valve (12) controls the maximum pressure of the engine oil from the engine oil pump. If the pressure from the pump becomes excessive, the relief valve opens and some of the engine oil returns to the engine oil pan.Engine oil cooler (9) reduces the temperature of the engine oil. The engine oil cooler has bypass valve (11) that is designed to open if the cooler becomes restricted.
Illustration 4 g06325082
Front side of the engine
(7) Turbocharger oil supply line
(8) Turbocharger oil drain line
(15) Adapter
(16) Engine oil filter bypass valve
(17) Engine oil filter housingEngine oil filter housing (17) holds three internal engine oil filters. The base has an internal bypass valve. The oil filter housing has a bypass valve (16) on the end.The bypass valve will open if there is a restriction in the engine oil cooler or in the engine oil filter. The bypass allows the engine to be lubricated if the engine oil cooler is plugged or if the engine oil filter is dirty.Clean engine oil from the engine oil filters goes through adapter (9) into the block. Part of the engine oil goes to left camshaft oil gallery (2). The remainder of the engine oil goes to main engine oil gallery (1).Engine oil galleries (2) and (3) supply engine oil through drilled passages to the camshaft bearings. The engine oil circulates around each camshaft journal. The engine oil then flows through the cylinder head and through the rocker arm housing to the rocker arm shaft. Some of the engine oil lubricates the valve stems. The remainder of the engine oil drains from the cylinder head to lubricate the pushrods, the valve lifters, the camshaft, and the camshaft bearings.Engine oil from main engine oil gallery (1) is supplied to the main bearings through drilled passages. Drilled holes in the crankshaft supply engine oil from the main bearings to the connecting rod bearings. Engine oil from the rear of the main engine oil gallery goes to the rear of right camshaft oil gallery (3).Two sequence valves (6) allow engine oil from main engine oil gallery (1) to enter engine oil galleries (4) for piston cooling jets (5). The sequence valves will not allow engine oil into gallery (4) for the piston cooling jets until there is pressure in the main engine oil gallery. This reduces the amount of time that is required for pressure buildup when the engine is started.
Illustration 5 g06294913
(18) Piston cooling jet
Illustration 6 g06165422
Piston cooling jet
There is a piston cooling jet (18) below each piston. Each piston cooling jet has two openings. One opening is in the direction of a passage in the bottom of the piston. This passage takes engine oil to a manifold behind the ring band of the piston. A slot (groove) is in the side of both piston pin bores to connect with the manifold behind the ring band. The other opening is in the direction of the center of the piston. This helps cool the piston and this lubricates the piston pin.
Illustration 7 g03890856
Turbocharger oil lines
(7) Turbocharger oil supply line
(8) Turbocharger oil drain lineSupply line (7) provides engine oil for lubrication of the turbocharger bearings. The engine oil flows through drain line (8) into the camshaft cover.Engine oil is provided to the front and rear gear groups through drilled passages in the front housings, in the rear housings, and in the faces of the cylinder block. These passages are connected to engine oil galleries (2) and (5) for the camshafts.After the oil has completed lubrication, the engine oil returns to the engine oil pan.