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 valve
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 are these:
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 -cylinder counterpart.