Jeep Engines - Oljeep

70 MOPAR PERFORMANCE PARTSINTRODUCTION(Refer to Figure 2-73.)The 2.SL engine uses a pressure feed, full flow filtrationoiling system utilizing a positive displacement, gear-typeoil pump driven by the distributor shaft. The oiling systemhas a capacity of 3.8L (4 quarts). (For more oiling systemspecifications, refer to 2.5L Engine Spec@ations, ‘EngineAssembly’ section of this chapter.)A gear-type positive displacement pump is mounted at theunderside of the block opposite the No. 4 main bearing, Thepump draws oil through the screen and inlet tube from thesump at the rear of the oil pan. The oil is driven between thedrive and idler gears and pump body, then forced throughthe outlet to the block. An oil galley in the block channelsthe oil to the inlet side of the full flow oil filter. Afterpassing through the filter element, the oil passes from thecenter outlet of the filter through an oil galley that channelsthe oil up to the main galley which extends the entire lengthof the block.Galleries extend downward from the main oil galley to theupper shell of each main bearing. The crankshaft is drilledinternally to pass oil from the main bearing journals (exceptNo. 4 main bearing journal) to the connecting rod journals.Each connecting rod bearing cap has a small squirt hole. Oilpasses through the squirt hole and is thrown off as the rodrotates. This oil throw off lubricates the camshaft lobes,distributor drive gear, cylinder walls, and piston pins.Oiling SystemThe hydraulic valve tappets receive oil directly from themain oil galley. Oil is provided to camshaft bearingsthrough galleys. The front camshaft bearing journal passesoil through the camshaft sprocket to the timing chain. Oildrains back to the oil pan under the No. I main bearing cap.The oil supply for the rocker arms and bridged pivotassemblies is provided by the hydraulic valve tappets whichpass oil through hollow pushrods to a hole in thecorresponding rocker arm. Oil from the rocker armlubricates the valve train components, then passes downthrough the pushrod guide holes in the cylinder head pastthe valve tappet area, and returns to the oil pan.Oil Pressure RequirementsOil pressure requirements for the 2.5L engine are as follows:At Idle Speed (800 rpm) . . . , 25-35 psi . . . . 172-241 kPaAt 1,600+ rpm. . . . . . . . . . . . 37-75 psi . . . .255-517 kPaOil Pressure Relief . . . . . . . . 75 psi. . . . , . . 517 kPa