ARRANGEMENT OF CYLINDERS

Engines are also classified according to the arrangement of the cylinders (fig. 2-10): in-line with all cylinders cast in a straight line above the crankshaft; v-type with two banks of cylinders mounted in a V-shape above the crankshaft; horizontal opposed with cylinders arranged 180 degrees from other with opposing cylinders sharing a common crankshaft journal; and radial with the cylinders placed in a circle around the crankshaft.

IN-LINE—In-line is a common arrangement for both automotive and truck applications. It is commonly built in four- and six-cylinder configurations.

V-TYPE—V-type is also a common arrangement for both automotive and truck applications. The V-type engine in a six-cylinder configuration is suitable for front-wheel drive cars where the engine is mounted transversely.

HORIZONTAL OPPOSED—This engine is designed to fit into compartments where height is a consideration. It is used for air-cooled configurations.

RADIAL—This engine is designed almost exclusively for an aircraft engine.

The cylinders are numbered. The cylinder nearest the front of an in-line engine is number 1. The others are numbered 2, 3, 4, and so on, from front to rear. In V-type engines, the numbering sequence varies by manufacturer. You should always consult the manufacturer's manual for the correct order.

The firing order (which is different from the numbering order) of the cylinders of most engines is stamped on the cylinder block or on the manufacturer’s nameplate. If you are unable to locate the firing order and no operation or instruction manual is available, turn the engine over by the crankshaft and watch the order in which the intake valves open.