Subject: Water Injection + Vapor Carburetor

From: [email-masked] (Gene A. Townsend)
Date: 30 Nov 1996 06:58:01 -0700

A recent post has reminded me of these two principles, water injection
and  vapor carburetion, that are worth discussing.

Both of these are common scams.  "Vapor Carburetor Doubles Fuel
Economy, only $19.95"  How many times have I seen this ad in the
classified of Popular Science Mazine, among others?

Both of these are also a benefit, under certain special circumstances.

Applied to automotive engines, they are of dubious value.  Automotive
engines operate at very low power levels on the average, down around
20% of rating, and water injection rate would be difficult to regulate
without using a microcontroller sensing feedback exhaust gas
temperature.  This would be expensive, and compete with existing
microcontroller on current cars.  Could only be applied to
non-computerised fueld injected engines.

The vapor carburator is too dangerous to use on passenger vehicles.

Both of these are very beneficial to small gas engines of the type
used to generate 1 KW to 10 KW or so electricity, especially when the
engine is operated at over 50% of its power rating.  Small gas engines
in the 3 to 16 HP size have between 12% and 18% fuel effeciency, and
stand to gain the most.

Water Injection

Primary function is to cool engine selectively during intake and
compression strokes.  Before the spark ignites, all the water should
be fully vaporized.  This reduces the power needed in compression,
increases the volmetric effeciency, and tends to keep the engine clean
due to extra steam in the exhaust.  If overdone, it will reduce the
engine efficiency.  In the range of 1% to 5% is typically optimal.

Vapor Carburetors

100% vaporization of gasoline fuel results in clean burning and
extremely lean burn potential.  It is also dangerous.  Very early
gasoline engines used what looked like a small swimming pool full of
gasoline, with a lid near the fuel surface.  Intake air was drawn over
the gasoline surface to create fuel vapor.  There are other more
modern techniques that look more like humidifiers than carbs.

Again, applied to cars, the vapor carb is useless.  A full lean burn
mix requires a specific, constant load, like a generator charging a
battery bank, rather than a changing road load.  It, along with vapor
injection at high rates, requires changing the spark timing of the
engine.

Together, they can enhance the 12% to 18% small engines up into the
mid 20% range, nearly double in the case of the smallest engines.

Hope it helps

Gene A. Townsend

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From: [email-masked] (Charles)
Date: Sat, 30 Nov 1996 11:54:10 -0600

> mid 20% range, nearly double in the case of the smallest engines.

This brings back memories of my Dad using our grist mill. We had a modle T
engine to operate it and as the engine became loaded down by the mill we
could sprinkle a small amount of water droplets into the intake and the
engine would come back to life (kinda like a kick in the butt).

Charles