W. D. Thompson Steam Car Engine


W D Thompson Steam Car Engine

  W D Thompson Steam Car Engine
2 1/4" bore, 4 1/2" stroke uniflow

This engine was purchased at auction in the Oxnard, California area and thus no information comes with it.  I am guessing it is the Thompson engine and have found two references to Thompson.  One is a report in the 1966 Steam Automobile publication Vol. 8  #4 where a fluff piece was written to go along with a well done drawing of a big luxury car that looks like a cross between a Cadillac and a Lincoln. 

The other reference is in the April 1969 issue of a publication called Information on Developments in Electricity And Steam a monthly report that was very expensive and put out by International Research and Technology Corp. out of Washington D.C.  This publication went on for about three years and covered all of Bill Lear’s work and a lot of other things of that time.  It is a great source of historical information.

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W D Thompson Steam Car Engine   W D Thompson Steam Car Engine

They report on a proposed steam car racing program out of San Diego designed by William D. Thompson.  The projected engine is a “very small, flat, horizontally opposed six-cylinder reciprocating unit.  It is a single-acting type, of uniflow design, with single expansion.  Cylinder bore is 2 ¼ in; stroke is 4 ½ in: overall engine block size is approximately 24 in. square and 16 inches in depth.”. 

This description clearly matches the engine illustrated along with its current owner.  The cover to the cam box did not come off with only modest pounding and prying and so we do not know what the insides look like.  The owner is quite proud of this engine and therefore I could not get the engine apart while he was watching.  The cylinders are very close together.  In fact they are touching and they are welded together.  The push rods quite clearly push open the exhaust poppet valves and pull open the intake valves: all conventional and good design.  The engine shows very good craftsmanship. 

W D Thompson Steam Car Engine   W D Thompson Steam Car Engine

Unfortunately we do not know where the steam generator has gone.  It would be a good thing to have because, and according to Thompson, it is able to produce 2,000 pounds per hour of steam using “very little” fuel.  We are all looking for a steam generator that uses very little fuel.  According to my rough calculations it would take about 18 gallons per hour of kerosene to produce 2,000 pounds of steam per hour in the kinds of monotube steam generators that we make that are 85% efficient. 

The steam power system has some other very clever ideas.  For an example there is a “reactor” in the middle of the combustion chamber that is quite small and electrically powered consuming 1.5 kw that operates at 3000 degrees F and both pre-heats feed water and superheats the steam.  The reactor uses pure oxygen that is made by a water electrolysis device.  To insure complete condensation of exhaust steam there is an electrical refrigeration unit to cool the air used for condensing. 

And just to show that Mr. Thompson has thought of everything he has designed a new two-cycle IC engine that is “very small, self-supercharged and fuel-injected” and this powers the 6 kw alternator unit, thus providing plenty of electricity for the “reactor, refrigeration unit, water hydrolysis device, power steering and most other road vehicle accessories”. 

W D Thompson Steam Car Engine   W D Thompson Steam Car Engine

Thompson is constructing two racing machines but they are not going to be ready for the Indy 500 in May however two Grand Prix cars will definitely be in the 1970 Le Mans GP.

Here is the editor’s note at the end of this report: “The system Thompson described is difficult to rationalize in terms of conventional technology.  We suspect it is still largely a paper design, and that if built it will not work as well as Mr. Thompson expects.  Possible we fail to grasp the significance of the mysterious “reactor.”  We look forward to seeing the first working model.”           

And that is all that we know and we do not even know that this for sure is the engine.  It appears to be a perfect match and it shows real development work.  The history of steam power is strewn with these half reported stories and by now the principles are all dead and being good engineers they have left no record.