52 Auto Fundamentals
In the T-head engine, both valves are in
the block and on opposite sides of the cylinder,
Figure 3-4. The F-head places one valve in the
head and one in the block, Figure 3-5. These
designs have been obsolete for many years.
I-Head
In the I-head engine, both valves are located
in the cylinder head. They may be arranged in a
straight line, Figure 3-6 or staggered, Figure 3-7.
An I-head engine is commonly referred to as an
overhead valve engine.
Since the valves are placed in the I-head, a valve
train must be used to operate them. Figure 3-8
Piston
Head
Block
Valve
Lifter
Figure 3-3.
L-head engine. Valves are in the block, both on the same
side. Note upside down L shape. This design is no longer
used in automotive engines, but can be found in some
small low-horsepower engines.
TRW, Inc.
Figure 3-4.
T-head confi guration. Like the L-head engine, the valves
are in the block. This confi guration has been obsolete for
many years.
Goodheart-Willcox Publisher
Valve
Valve
Piston
Figure 3-5.
F-head engine. Note that there is one valve in the block
and one in the head. This design is also obsolete.
TRW, Inc.
Piston
Valve
Figure 3-6.
I-head engine. Both valves are located in the head.
TRW, Inc.