The Universal 'Jeep', originally designed for rugged war operation,
has been strengthened and adapted to many industrial and agricultural
applications. To date, the Hurricane engine has supplied more than
enough power to meet any challenge presented to the Universal 'Jeep'.
Once the uses of each Willys engine have been discussed, the
differences between each power plant will be covered in greater detail.
BUT FIRST --
What is an F-head engine? Engines are typed by the pattern the
fuel mixture makes as it travels from the intake valve to the exhaust
The F-head engine for example, has the intake valves in the
cylinder head above the cylinder. The exhaust valves are in the block at
the side of the cylinder below the intake valves. Thus the fuel mixture
enters the cylinder chamber from the top, travels down the length of the
chamber, back up and out through the exhaust valves. The whole pattern
forms the letter "F".
In the L-head engine, the intake and exhaust valves are both
located in the engine block, side by side. The fuel mixture enters the
cylinder chamber through the intake valves, travels down and up the
cylinder and is ejected through the exhaust valves. The path of the fuel
mixture forms an inverted "L".
In general, the differences between a four and a six-cylinder engine
A four-cylinder engine is usually less expensive to manufacture,
sell, maintain and operate. It uses less gas. Because it is less
complicated it has fewer moving parts. This cuts down friction. The
pistons fire 180° apart, or two per crankshaft revolution.
The six-cylinder engine pistons fire 120° apart, or three per
crankshaft revolution, giving smoother performance and allowing more
torque to be developed. A low idling speed may be maintained. All this
adds up to less vibration in the six-cylinder engine. The big advantage
of this engine is its capacity to produce more power than its four