Figure 2-38. Single Overhead Camshaft Configurations
(3) Double Overhead Camshaft (Fig. 2-39).
applications alike. It is commonly built in four- and six-
This configuration has its camshafts located in the
cylinder configurations. Until approximately 30 years
cylinder head. When the double overhead camshaft is
ago, it was common to build an in-line engine with eight
used, the intake and the exhaust valves each operate
cylinders. As the cars became shorter and wider, the in-
from a separate camshaft. Each camshaft operates the
line eight-cylinder engine was replaced by the V-
valves directly through the lifters. This configuration,
though cumbersome, provides the most engine
performance and is used mostly in more expensive
c. F-Head Engines (Fig. 2-40). The F-head engine
is a combination of the two valve arrangement groups. In
this engine, the intake valves are of the overhead type,
located in the cylinder head. The exhaust valves,
however, are located in the cylinder block. The engine
gets its name by the Imaginary letter F formed by the
cylinder and the valve heads. This configuration usually
is not used In current automotive design.
2-19. Classification by Cylinder Arrangement.
Multicylinder engines are classified by cylinder
arrangement. Each cylinder arrangement has its own
advantages. The most common arrangements are
shown in figure 2-41.
a. In line (A, Fig. 2-41). This is a very common
Figure 2-39. Double Overhead Camshaft
arrangement in automotive and truck