HEAD 3943594 - Caterpillar

Illustration 1 g01112073
(1) Unit injector hydraulic pump (2) High pressure relief valve (3) Oil passage to the rocker arms (4) High pressure oil line (5) Valve mechanism cover (6) High pressure oil passage (7) Oil supply line to the unit injector hydraulic pump (8) Cylinder head gallery (9) Oil gallery plug (10) Piston cooling jets (11) Camshaft bearings (12) Oil filter bypass valve (13) Oil cooler bypass valve (14) Main oil gallery (15) Passage to front housing (16) Turbocharger oil supply line (17) Passage to camshaft idler gear bearing (18) Passage to cylinder block (19) Passage to oil pump idler gear bearing (20) Engine oil filter (21) Engine oil cooler (22) Main bearings (23) Engine oil pump (24) Oil pump bypass valve (25) Passage to engine oil pan (26) Engine oil panThe engine oil pump (23) is mounted to the bottom of the cylinder block. The oil pump is located inside the oil pan (26) . The engine oil pump (23) pulls oil from the engine oil pan (26) . The engine oil pump pushes the oil through the passage to the engine oil cooler (21) . Oil then flows through engine oil filter (20) . The filtered oil then enters the turbocharger oil supply line (16) . The filtered oil also enters the main oil gallery (14) .
Illustration 2 g01135280
Remote mounted oil filter (12) Oil filter bypass valve (13) Oil cooler bypass valve (20) Oil filter (21) Oil cooler
Illustration 3 g01112098
(1) Unit injector hydraulic pumpThe main oil gallery (14) distributes oil to the following areas: main bearings (22) , piston cooling jets (10) and camshaft bearing (11) . Oil from main oil gallery (14) exits the front of the block. The oil then enters a groove that is cast in the front housing.Oil enters the crankshaft through holes in the bearing surfaces (journals) for the main bearing (22) . Passages connect the bearing surface (journal) for the main bearing (22) with the bearing surface (journal) for the connecting rod.The front housing passage sends the oil flow in two directions. At the upper end of the passage, oil is directed back into the block. The oil then flows up to the cylinder head gallery (8) through passage (3) to the rocker arm mechanism. A passage (19) sends oil to the oil pump idler gear bearing.Oil from the front main bearing enters a passage (17) to the camshaft idler gear bearing. Oil passages in the crankshaft send oil from all the main bearings (22) through the connecting rods to the connecting rod bearings.Note: Engines that are equipped with an auxiliary oil filter will receive oil from a port. The filtered oil will be returned to the engine oil pan (26) .The unit injector hydraulic pump (1) is a gear-driven axial piston pump. The unit injector hydraulic pump raises the engine oil pressure from the typical operating oil pressure to the actuation pressure that is required by the unit injectors.The oil circuit consists of a low pressure circuit and a high pressure