Abstract: A method for designing and producing an internal combustion engine of the reciprocating type which allows for reducing the number of cylinders required for smooth operation of an engine of any size displacement. A new balancing procedure for dynamically balancing the crankshaft and reciprocating parts overcomes the vibration forces produced by the high moments of inertia inherent in reciprocating engines with a single plane crankshaft and large cylinder bores. The engine designed and assembled in accordance with this procedure may have fewer cylinders and moving parts than engines produced and assembled with balancing methods in current use, but with the same total volume of cylinder bore displacement.