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Constant Volume Piston Dwell* "CVPD™" (see note below)

This patent pending technology is based on advancements in the design of the internal combustion engine. These advancements utilize an alternate method of connecting the piston to the crankshaft, creating a different geometry, which provides an increase in the system’s mechanical advantage while improving volumetric efficiency.  The design applies equally to both spark ignition and compression ignition engines.

The design geometry creates a pause or dwell in the piston’s movement at TDC (top dead center) and BDC (bottom dead center) while the crankshaft continues to rotate for up to 90 degrees.  Adding these CONSTANT VOLUME” dwell cycles improves fuel burn, maximizes pressure, and increases cylinder charge.   Fuel burn can be precisely controlled by maintaining a minimum volume (TDC piston dwell) throughout the burn process.  Containment maximizes pressure and burn efficiency.  This dwell allows the crankshaft to rotate to the greatest mechanical advantage (90 degrees), thus maximizing power output.  In like manner, holding the piston at maximum volume (BDC piston dwell) provides additional time for the cylinder to fully charge before closing the intake valves. The design creates an eight-cycle (8C) process.  Theoretically, compared to conventional designs, this technology represents a promise of more than 300% increase in the power out for the same energy in or conversely less fuel for the same power.

In practice, a proof of concept (POC) prototype has empirically demonstrated that a 280% increase is obtainable with the promise of more. This same prototype has been used to physically measure the volumetric advantages as well.  When comparing the CVPD engine to modern engines with variable valve timing, the new technology offers 24% to 63% improvements throughout the engine’s rpm range, with the greatest improvement at the higher rpm.

A third advantage further enhances the volumetric efficiency. The piston travels from TDC to BDC in 90° of rotation of the crankshaft, twice normal speed, which creates greater air mass momentum, improving cylinder charge.

Finally, the dwell times allows the exhaust and intake valves to fully open and close without overlap while the piston is maintained in the dwell states.

*Note: Name (formerly CVCI™) changed to clarify the mnemonics and to remove any potential conflicts.


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