Pivotal Engineering of Christchurch, New Zealand has designed and built a new two stroke engine. The pivotal engine utilizes a pivoting wedge shaped piston that pivots on a shaft while the driving force is transferred by a connecting rod from the bottom of the piston to the crankshaft. The piston itself is directly cooled by water which circulates through the piston from the pivot shaft. The water cooled piston allows precise temperature control not previously possible.
The pivot motion eliminates the rocking motion of the piston in a conventional piston two stroke, dramatically reducing wear during cold startups, it controls the seals so they work more efficiently and dramatically reduces oil consumption to 10 percent of a conventional two stroke.
Although many applications are suitable for this engine, it was actually conceived to overcome durability problems in two stroke GP motorcycles and therefore is very well suited to everything from commuter scooters to high performance bikes.
There is an extensive discussion on the site of the pivotal engine’s suitability for use as a hydrogen powered internal combustion engine along with the necessary requirements for any engine designed to burn hydrogen directly and why the pivotal engine addresses these issues so well. The engine can also be designed to run on compressed natural gas.
The Flash animation on their site, which you really need to see, makes the operation of the engine very clear and it looks quite promising. Now this is a hydrogen motorcycle engine I could like!