In a car, should the engine cease to operate, the driver
is usually not
endangered, just inconvenienced. In a boat, aircraft, or certain other
situations, an ability to continue operating with a damaged engine could
be
an important life saving benefit. According to our experience so far, the
LIM type engine has no self-destructive parts, but there has been an
experience with an early version part failing during operation.
In the normal course of engine development, weak links
are encountered,
analyzed, and re-engineered. We think any LIM type engine will be less prone
to part failure than any comparably built counterpart. At one time, in an
experimental three-cylinder engine, an experimental valve fell into the
cylinder.
In any conventional four-stroke engine, or a Detroit Diesel
type two-stroke
engine, the same thing could, and has, happened. This is always an emergency
requiring the immediate cessation of operation. This is because the loss
of a
conventional valve into the cylinder is dangerous to the entire structure
of
the engine.
Jammed between the piston crown and the cylinder head with
the engine
running, the conventional valve, especially if broken, will tend to punch
a
hole either in the cylinder head, or in the piston crown. A hole in the
piston crown exposes all the oil in the crankcase to the combustion of fuel
and air, and also allows the pressure in the crankcase to eject the lubricant
through the cylinder into the exhaust manifold. A hole punched in the
cylinder head may release nothing at all in a LIM type engine, but in
conventional engines either coolant or oil may be released, which can lead
to
very serious damage, if not the complete destruction of the engine.
A total loss of lubricant will usually cause an engine
to seize and become
completely worthless.
Should a valve in a LIM type engine fall into a cylinder,
there is
practically no likelihood of such severe damage to the piston or the head.
The cylinder lacking its valve will cease to make power, but the remaining
cylinders will be unaffected. In a boat, airplane, or emergency vehicle
there would be no compelling reason to cease operations prior to reaching
a
place of safety, such as a harbor, an airport, or the lifesaving destination.
Since the single occurrence of a valve failure in
a LIM type experimental
engine, the valves and the valve retaining systems have been redesigned,
but
the LIM type engine will prove to be efficient, reliable, and rugged.
