9. Figure 5-1 Oil molecules cling to metal surfaces but easily slide against each other.

10. Figure 5-2 Wedge-shaped oil film developed below a moving block.

11. Figure 5-3 Wedge-shaped oil film curved around a bearing journal.

13. Figure 5-4 Typical V-8 engine lubrication system. Oil is stored in the oil pan (sump), drawn into the oil pump, and moves through the oil filter and on through the oil passages (oil galleries).

23. Figure 5-5 API doughnut for a SAE 5W-30, SM engine oil. When compared to a reference oil, the “energy conserving” designation indicates a 1.1% better fuel economy for SAE 10W-30 oils and 0.5% better fuel economy for SAE 5W- 30 oils.

31. Figure 5-6 The International Lubricant Standardization and Approval Committee (ILSAC) starburst symbol. If this symbol is on the front of the container of oil, then it is acceptable for use in almost any gasoline engine.

45. Figure 5-7 Container of oil with the ILSAC starburst symbol on the front. The tri-synthetic label indicates that it contains Group IV (POA) as well as Group V (diesters) to swell seals, and some Group III (hydrocracked oil).

46. Figure 5-8 Both oils have been cooled to -20 degrees F (-29 degrees C). Notice that the synthetic oil on the left flows more freely than the mineral oil on the right even though they are both SAE 5W-30.

56. Figure 5-9 (a) A pick is pushed through the top of an oil filter that is positioned vertically. (b) When the pick is removed, a small hole allows air to get into the top of the filter which then allows the oil to drain out of the filter and back into the engine. A

57. Figure 5-9 (continued) (a) A pick is pushed through the top of an oil filter that is positioned vertically. (b) When the pick is removed, a small hole allows air to get into the top of the filter which then allows the oil to drain out of the filter and back into the engine. B

60. Figure 5-10 A rubber diaphragm acts as an antidrainback valve to keep the oil in the filter when the engine is stopped and the oil pressure drops to zero.

61. Figure 5-11 A cutaway of an oil filter showing the location of a typical bypass valve. When the oil filter becomes clogged, the bypass valve opens, allowing the engine to receive oil even though it is not filtered.

62. Figure 5-12 A typical oil filter crusher. The hydraulic ram forces out most of the oil from the filter. The oil is trapped underneath the crusher and is recycled.

67. Figure 5-13 An oil pump driven by the camshaft.

68. Figure 5-14 A typical oil pump mounted in the front cover of the engine that is driven by the crankshaft.

69. Figure 5-15 Geroter-type oil pump driven by the crankshaft.

70. Figure 5-16 In a gear-type oil pump, the oil flows through the pump around the outside of each gear. This is an example of a positive displacement pump, wherein everything entering the pump must leave the pump.

77. Figure 5-17 Oil pressure relief valves are spring loaded. The stronger the spring tension, the higher the oil pressure.

78. Figure 5-18 A typical engine design that uses both pressure and splash lubrication. Oil travels under pressure through the galleries (passages) to reach the top of the engine. Other parts are lubricated as the oil flows back down into the oil pan or is splashed onto parts.

79. Figure 5-19 An intermediate shaft drives the oil pump on this overhead camshaft engine. Note the main gallery and other drilled passages in the block and cylinder head.

84. Figure 5-20 (a) A visual inspection indicated that this pump cover was worn. (b) An embedded particle of something was found on one of the gears, making this pump worthless except for scrap metal. A

85. Figure 5-20 (continued) (a) A visual inspection indicated that this pump cover was worn. (b) An embedded particle of something was found on one of the gears, making this pump worthless except for scrap metal. B

86. Figure 5-21 (a) The oil pump is the only part in an engine that gets unfiltered engine oil. The oil is drawn up from the bottom of the oil pan and is pressurized before flowing to the oil filter. (b) If debris gets into an oil pump, the drive or distributor shaft can twist and/or break. When this occurs,the engine will lose all oil pressure. A

87. Figure 5-21 (continued) (a) The oil pump is the only part in an engine that gets unfiltered engine oil. The oil is drawn up from the bottom of the oil pan and is pressurized before flowing to the oil filter. (b) If debris gets into an oil pump, the drive or distributor shaft can twist and/or break. When this occurs,the engine will lose all oil pressure. B

88. Figure 5-22 Gear-type oil pump being checked for tooth clearance in the housing.

89. Figure 5-23 Measuring the gear-to-cover clearance of an oil pump.

94. Figure 5-24 Oil flow through an engine starts at the oil pump pickup and eventually ends up with the oil dropping back into the oil pan.

95. Figure 5-25 The rocker arm pivot is lubricated through the oil passage in the bottom of the rocker shaft. Other rocker arm styles are usually lubricated through a hollow pushrod.

96. Figure 5-26 Windage tray attached between the crankshaft and the oil pan.

98. Figure 5-27 Typical engine oil cooler. Engine oil is cooled by passing coolant from the radiator through the auxiliary housing. The oil filter screws into the cooler.

100. Figure 5-28 The oil pressure switch is connected to a warning lamp that alerts the driver of low oil pressure.

103. Figure 5-29 A typical oil pressure sending unit on a Ford V-8.