MBE 4000 – Section 3.1 Lubrication System Description

Section 3.1
Lubrication System Description

The MBE 4000 engine features a full-flow filtered, pressurized lubricating oil system. The system incorporates various valves and restricted orifices to optimize the oil flow. External piping and plumbing is kept to a minimum to avoid oil leakage.‪

The lubricating system consists of the following components:‪

• Oil pump
• Pressure relief valve
• Oil filter
• Oil cooler
• Oil level dipstick
• Oil pan
• Breather System

An internal tooth gear pump is mounted to the bottom rear of the engine block and direct driven by the crankshaft at 1.06 times engine speed. The location of the oil sump pick-up tube varies with oil pan choice.‪

The oil pump pulls oil from the oil pan through the pick-up tube. Oil leaving the pump is routed through the oil cooler, then to the oil filter and bypass valve. If the oil pressure is too high, the oil is routed through the pressure relief valve on the oil pump to the oil pan. The filtered oil is then routed into the main oil gallery in the cylinder block. From there, the oil is distributed to the crankshaft, rods, pistons and then to the camshaft bearings. Oil spray nozzles are installed in the block, which provide a continuous spray of oil to the underside of the pistons. From the camshaft bearings, oil is routed to oil passages in the cylinder head, which deliver oil to the valve train components and rocker arm pedestals. Some oil is delivered to the rear of the camshaft to help control camshaft end play. A camshaft bearing galley supplies oil for the spray nozzles which provides a continuous supply of oil to the camshaft lobes, valve tappets, and the unit pump rollers. The oil drains from the cylinder head to the oil pan. Oil for gear train components at the front of the engine is fed through drilled holes out of the main gallery. The turbochargers oil supply is taken from the oil galley circuit. Oil from the turbocharger returns to the crankcase via an external tube. A mechanical oil separator pulls any oil droplets out of the crankcase vapor and returns the oil back into the oil pan. The clean air is then returned to the atmosphere. See Figure "Engine Oil Flow Diagram" .

1. Camshaft‪	6. Oil Pick-up Tube‪
2. Rocker Arms and Shafts‪	7. Piston Oil Spray Nozzle(s)‪
3. Oil Filter‪	8. Oil Pump‪
4. Oil Cooler Element‪	9. Crankshaft‪
5. Turbocharger Oil Return Line‪

Figure 1. Engine Oil Flow Diagram

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