If you adjust your mixture to slightly
lean then the flame temperature will increase. Less fuel > more heat. You
get better fuel economy with a slightly lean mixture but you risk heat damage,
and the maximum available power will be reduced.
Modern light aircraft often have a mixture
control which can be adjusted to increase cruising range by operating slightly
lean. They also have temperature sensors on either the cylinder heads or
the exhaust manifold. It is standard procedure to increase the mixture
to a richer state if the temperature rises too high. They use fuel
to cool the engine.
The same wasteful use of fuel
is happening inside your motor car. Your vehicle would get better fuel economy
if operating lean, but it would overheat and suffer damage, unless
you use water to cool the flame.
Water injection:
-
Prolongs engine life by controlling heat.
-
Allows for improved fuel economy by running leaner mixtures.
-
Keeps the cylinders and pistons clean by continuously steam cleaning.
-
Helps prevent pinging by cleaning away carbon deposits and cooling the
combustion process.
-
Reduces oxides of nitrogen pollutants by reducing the temperature.
Methods:
Just to clarify, by injection we
don't necessarily mean mechanical injection as in diesel or EFI. The water
can be admitted by suction using existing vacuum fittings. There are 3
basic methods.
In common with all three is the need for the water to enter the engine
as very fine droplets.