USE OF MULTICYLINDER ENGINE
If, in a multi cylinder engine, power strokes are staggered, the limitation of flywheel can be overcome to a large extent. Torque diagram for 2 cylinder, 4 cylinder, 6 cylinder, and 8 cylinder engines are shows that it is seen that mean ratio of maximum to mean torque is about 8 in case of single cylinder engine, which is gradually reduced as the number of cylinders is increased and is about 1.1 in case of an 8-cylinder engine. This is the main reason why in case of automobiles, multi cylinder engines are employed in preference to single cylinder engines of bigger size.
COMPARISON OF SINGLE AND MULTILAYER ENGINES:
1. Power output is more uniform in case of multilayer cylinder engines due to increases in frequency of power impulses with the increase in the number of cylinders.
2. A multi cylinder engine of comparable size would have smaller cylinders, which means the greater surface to volume ratio leading to more cooling. Therefore higher compression ratios can be used without the occurrence of detonation.
3. Due to lighter reciprocating components and smaller flywheel, accelerations response in case of a multi cylinder engine is quicker.
4. As the number of cylinders increases, torsion vibrations become a problem.
5. As the number of cylinder increases, mixture distribution in case of carburettor engines becomes difficult.
6. With more number of cylinders, the cost of providing exactly duplicate components in various cylinders becomes excessive.