A two-stroke of genius

Rugby-based engineer Bryan Parsons has received a UK NESTA Invention & Innovation Award of £66,000 to develop a simple new engine for hand-held power tools.

Rugby-based engineer Bryan Parsons has received a NESTA (National Endowment for Science, Technology and the Arts) Invention & Innovation Award of £66,000 to develop a simple new engine for low cost and easy-to-use, hand-held power tools.

Parsons’ design is a single cylinder two-stroke engine that has asymmetric port timing (in symmetrically timed engines, the exhaust port opens first and closes last whilst in asymmetric engines the inlet valve closes last, giving better breathing and lower emissions).

The new design differs from conventional two-stroke engines in three ways: the engine has a novel integrated design of conrod and piston, the piston is internally oil cooled and the gas sealing ring is of special design.

The NESTA award will allow Bryan to develop a pre-production prototype with an output of approximately 2kW.

The engine, which is expected to be cheaper, lighter and more environmentally friendly than standard designs, can also be fully mechanically balanced. This will lower vibration levels, and should improve the fatigue associated with operating hand-held machines.

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