V20 Engine Firing Sequence for Torsional Vibration Reduction

The 20-cylinder V-engine is segmented into two banks of 10 cylinders each, with each bank further divided into groups that fire in a specific sequence. This segmentation allows the complex 20-cylinder system to be managed through modular firing sequences (e.g., A1-B3-A4-B9-A8-B5-A2-B1-A5-B4-A10-B8-A7-B2-A3-B6-A9-B10-A6-B7), reducing the overall torsional dynamics complexity while maintaining high power output.

The patent implements a periodic firing sequence where cylinders are ignited in a carefully planned cycle that distributes combustion events evenly throughout the engine operation. The sequence ensures that cylinders from both banks fire alternately with specific intervals (e.g., A1 fires, then B3 after a controlled interval, then A4, etc.), creating periodic action that balances the periodic forces on the crankshaft and reduces peak bearing loads.

The patent converts the potentially harmful torsional vibrations and dynamic loads into a beneficial design feature by using the optimized firing sequence to naturally balance the forces. Instead of requiring expensive vibration dampers and high-strength materials to counteract vibrations, the firing sequence itself creates a balancing effect where the periodic combustion forces from different cylinder banks counterbalance each other, reducing peak loads and allowing the use of less expensive materials.

The patent systematically varies and optimizes critical design parameters including the V angle between cylinder banks, the crank star configuration (arrangement of crank throws), and the firing sequence order. By changing these parameters in a coordinated manner, the design achieves optimized vibration dynamics where the geometric arrangement of cylinders and cranks works synergistically with the firing sequence to minimize vibrations, rather than treating each parameter in isolation.