A Car that Runs on Water Alone

In July 2005, an American mechanic released the details of his simple conversion system which allows an 
ordinary car to use water as the only fuel.  The details are as follows:  
  
The car, which he runs on a daily basis, is a restored, eight-cylinder 1978 Chevy ‘Camaro’ with stock 350 (5.7 
litre) engine, no computer controls, automatic transmission, stock 4-barrel carburettor and stock fuel pump.  The 
fuel tank has been replaced with a metal water tank with the filler cap vented to release heat and pressure.  The 
exhaust was replaced with a new 2 inch pipe which is ducted into the water tank.  The water tank has baffles 
inside it which also muffles the exhaust noise.  The stock exhaust manifolds were used, but they will rust on the 
inside - custom stainless steel pipes would be best but these were not used due to their cost.  

All of the stock ignition system is used and no changes have been made.  A second battery was placed on the 
opposite side in the engine compartment.  A 400 watt (800W peak) 110 volt 60Hz DC inverter was placed in the 
engine compartment on the passenger side and a fresh air duct located behind the grill directs air into covers 
placed around the inverter to keep it cool.  
  
When the ignition switch is on, a relay turns the inverter on, the relay lead contains a 20 amp in-line fuse.  This 
relay only turns the inverter on and off and has no other function.  The inverter is connected to the battery via a 
not the chassis).  The inverter is not grounded to the car at any point and 
positive wire and a negative wire (
instead, is carefully insulated to ensure that accidental grounding never occurs.  
  
The wire which would normally go to the spark plug is replaced by a wire which is taken to a box containing one 
pre-war mechanical twin-coil relay or vibrator per cylinder.  Each of these wires drives its own dedicated ‘relay’, 
the current energises the relay coil but the other side of the relay coil is left unconnected.  The wiring arrangement 
is shown in the diagrams below.  

It is important that the electrical feed to each plug is fed via one wire to the plug cap and a second wire connecting 
to a washer clamped under the spark plug.  This wiring is repeated for each of the spark plugs.  To emphasise 
this, each spark plug should have two wires running to it, one to the cap and one to the washer clamped between 
the body of the spark plug and the engine block.   The wiring is done with “12-2” wire which is 2-core solid copper 
wire American Wire Gauge size 12 which has core diameters of 2.05 mm giving 3.31 sq. mm. per core, the 
nearest SWG size is 14.   The under-plug washer can be made by bending the end of the solid core into a circle 
of appropriate size and then flattening the wire slightly.  

In the relay box, the relays are positioned with a one-inch gap between them.  It is important that the physical 
construction insures that all of the high-voltage connections are fully insulated should anyone open the relay box 
when the inverter is running.  The batteries used are deep-cycle types with high cranking current ratings – this is 
important because the inverter must stay on when the engine is being started and it will cut out if the starter motor 
current drain pulls the battery voltage down excessively.  The alternator is the stock 95 Amp type and it charges 
both batteries simultaneously.  When the engine is started, the relays are heard clicking until the cylinders fire and 
after that, no sound can be heard from the relays.  It is distinctly possible that the relays take up a fixed, immobile 
position when the engine is running.  The diagram below marked ‘Effective circuit’ is based on that assumption, 
and it should be stressed that all of the diagrams are only what I understand from the information provided to 
date.

The engine timing has to be retarded for the car to run off water.  This adjustment should be made to the point 
where the engine runs the best and this is likely to be different for each make of engine.  The Chevy ‘Camaro’ 
o
.  The spark plug gap used to be 65 thou. but is now set to 80 
engine runs best with the timing retarded by 35
thou. (0.08”).  The plugs used are the cheap ‘Autolite’ (25) copper core type.  Using carburettor jets two sizes 
larger than normal, allows the engine to produce more power and rev higher than tick-over.  
  
The engine tends to knock when first started from cold but it is likely that this can be overcome by using a heater 
on the water feed to the carburettor, raising the water temperature to say, 120 degrees Fahrenheit and fitted with 
a thermostat to disconnect the heater when the engine reaches its normal operating temperature.  This car has 
been run 30,000 miles on water alone and covers some 300 miles per gallon as much of the water vapour in the 
exhaust condenses in the water tank.  
  
The disadvantages: the car runs with slightly reduced power and the exhaust system will rust unless stainless 
steel replacements are used.  
  
The inventor of this conversion wants to go on living a quiet life and does not want the nuisance value of high 
levels of interest.  Consequently, he wishes to remain anonymous.  He says: “I didn’t build this to sell or to get a 
patent on it, or make big bucks from the information.  I did it because I could and I did.  The only thing I can add is 
‘just try it’.

Some points of note:

A car with this modification produces NO carbon dioxide and NO carbon monoxide, but since air is mixed with the 
gas combustion, it is likely that the greenhouse gas Nitrous Oxide is produced.  But Nitrous Oxide dissolves 
reasonably well in water, so since the exhaust gasses are passed through the header tank which contains the 
water fuel, it is likely that this engine arrangement is a good deal greener than most.  
  
The vented filler cap arrangement will not suit many European car designs which have a locking flap covering the 
filler cap.  For these cars, it would probably be better if the gas exiting from the water tank is passed through a 
normal exhaust pipe, and the filler cap be a screwed airtight fitting.