The present invention applies to all types of internal combustion reciprocating piston engines as the present invention allows for varying the piston travel upward stop position.  Additionally, the present invention allows for two different piston stroke travel lengths to be implement within a one complete four-cycle operation. 
Otto, Diesel, Joule-Brayton, Wankel, Atkinson, Moteki, and others, have created different apparatus and methods for internal combustion engines.  The present invention (known as the SOWDA engine) combine the positive benefits of the above-mentioned inventions into one unique all-encompassing design.  The benefits of four-stoke (Otto), constant pressure compression ignition (Diesel), infinitely variable compression ratio (Moteki), a long power stroke and a short compression stroke (Atkinson), and a balanced centrifugal rotating mechanism (Wankel) makes the present invention extremely unique and highly energy efficient.  The present invention provides an internal combustion engine with the Atkinson's long and short piston stroke length motions, the variable compression ratio concept similar to Moteki, the intake air flow throttling control of the Otto cycle, and the constant ignition pressure of the Diesel cycle. 
The present invention provides fixed long power and exhaust strokes with fixed short intake and compression strokes.  In practicality, the power and exhaust strokes may be set 40% to 50% longer than the intake and compression strokes. 
Energy/fuel consumption for lawn-tractors, golf carts, chain saws, automobiles, trucks, buses, airplanes, power generators, etc.  has become more and more critical to the economic stability and environmental stability of the earth.  Presently, no apparatus or method provides the intake air-flow throttling control of the Otto four-stroke cycle and the constant pressure ignition of the Diesel four-stroke cycle, while at the same time, applying the Atkinson long and short stroke cycles and packaged into a small balanced centrifugal rotating mechanism easily adapted to existing internal combustion technology at a reasonable expense.  Internal engines equipped with the present invention can operate on almost any fuel and perform at extremely high efficiencies with or without a turbo charger or super-charger.  As a result, the present invention can be applied to all reciprocating internal combustion engines using virtually any gas, liquid, or solid fuel, or any combination or blend, thereof.