Another method of classifying engines is by cylindrical arrangement. Cylinder arrangement is only applicable to multicylinder engines.
Number of popular cylinder arrangements are:
In-line Engine: This is an engine with one cylinder bank, all the cylinders are arranged linearly and transmit power to single crankshaft OR we can say that cylinders are positioned in a straight line one behind the other along the length of crankshaft. A Four and six cylinder in-inline engines are popular in automotive applications. In line engines are also called straight engines.
V Engine: In this engine there are two banks of cylinders inclined at an angle to each other and with one crankshaft. Most of high powered automobiles use 8-cylinder V engine. V engines also have even number of cylinders from 2 to 20 or more. V6 and V8 are common automobile engines.
Opposed cylinder engine: This engine has two cylinder banks on opposite sides of crankshaft. It is a well balanced engine. This design is used in small aircrafts.
Opposed Piston Engine: When single cylinder have two pistons each driving a separate crankshaft is called opposed piston engine. A single combustion process causes two power strokes at the same time with each piston being pushed away from center and delivering more power to a separate crankshaft. It incorporates complex mechanical linkage due to two rotating crankshafts or one crankshaft. Like opposed cylinder engine, it is also inherently well balanced due to opposed piston arrangement. These engines usually works on the principle of two stroke engines.
Radial Engine: When more than two cylinders are equally spaced around crankshaft in each row, called Radial Engines. These type of engines are commonly used in conventional air cooled aircraft engines with the configuration of 3,5,7 or 9 cylinders. Odd number of cylinders are employed from the point of view of balancing. Many medium to large size propeller driven aircrafts use radial engines. For large aircrafts two or more bank of cylinders are mounted together one behind the other on single crankshaft, making it powerful engine. There is an historical example of radial engine being mounted:
- Sopwith camel: A very successful world war 1 aircraft.
Delta Type Engine: Delta type is essentially a combination of three opposed piston engine with three crankshafts interlinked to one another.
XType Engine: this design is a variation of V-type. It has four banks of cylinders in X shape attached to a single crankshaft.
HType Engine: It has tow opposed cylinder types utilizing two separate but interconnected crankshafts.
W Engine: It is same as V engine except with three banks of cylinders on the same crankshaft. It is not common, developed for racing automobiles.