The AD3 diesel engine is produced by Perkins. It is also referred to as the AD3.152 engine. Like other Perkins engines, the name of the engine can provide some information about the engine design and performance. The "3" in the engine title refers to the number of cylinders, while the "152" refers to the total piston displacement of the engine in cubic-inches. The engine has been produced with the valves either at a 35- or 45-degree angle.
The Perkins AD3-152 engine has a piston displacement of 152.7 cu-in, or 2,502 cu-cm. The engine has a bore by stroke of 3.6 by 5 inches with a large compression ratio of 17.4 to 1. The engine also features four main-bearings. The maximum power output of the engine is 37 horsepower. The firing order of the pistons is in the following order: one, two and three. The engine low idle rpm is 700, while the high idle rpm is 2,160. The injection pump is model CAV-DPA. Cylinder liners are plated with chrome.
45-Degree Valve Angle Engine Torque and Dimensions
On the 45-degree valve angle AD3 engine, the cylinder head torque measures 55 to 60 foot-pounds. Main bearing cap torque is 90 to 95 foot-pounds. The big-end cap torque measures 45 to 50 foot-pounds while the flywheel bolt torque is 75 foot-pounds. The tappet, in hot temperatures, measures 0.010 inches; in cold temperatures it expands to 0.012 inches. The compression ring gaps and oil control ring gaps measure between 0.009 to 0.013 inches. The crank case can hold 1.75 gallons of oil while the cooling system holds 2.25 gallons of coolant. The injection pump timing measures -6.67 degrees C before top dead centre (BTDC). BTDC refers to crankshaft rotation, as well as the piston, just before it reaches the zenith of its upwards stroke. The crankshaft journal diameter measures 2.749 inches while the crank pin diameter is 2.249 inches. The piston pin diameter measures 1.25 inches.
35-Degree Valve Angle Engine Torque and Dimensions
With the 35-degree valve angle AD3 engine, the cylinder head torque is 70 to 75 foot-pounds. Main bearing cap torque is 110 to 115 foot-pounds. The bright-coloured big end torque nuts have a torque of 45 to 50 foot-pounds, while the black-coloured big end torque nuts have a torque of 60 to 65 foot-pounds. The flywheel bolt torque measures 75 to 80 foot-pounds. The injection pump timing measures 24-degrees BTDC. The crankshaft journal diameter measures 2.749 inches, while the crank pin diameter is 2.249 inches. The piston pin diameter measures 1.25 inches. The crank case can hold 1.75 gallons of oil while the cooling system holds 2.25 gallons of coolant. Top ring gaps are 0.014 to 0.03 inches, while the non-cord ring gaps are between 0.01 and 0.029 inches.