Performance diesel engine from Cox Powertrain to power-up tenders


The British Ministry of Defence (MOD) is co-funding the development of a lightweight diesel engine that could dramatically improve the performance of superyacht tenders.

‘The Cox opposed piston engine has game-changing potential for military and civil applications,’ says Charles Good, executive chairman of engine design company Cox Powertrain, ‘with weight and package size as low as 50 per cent of current conventional diesel engines.’

The engine concept, currently configured as an outboard engine, promises a power-to-weight ratio comparable with high performance petrol outboard engines, but at much reduced fuel consumption and having the safety and reliability of diesel.

While the MOD intends to use the engine on Royal Marines RIBS, it will be developed for civil vessels such as yacht tenders, workboats and, in the longer term, inboard engines for yachts. Apart from power, its creators believe the engine will offer a 30 per cent increase in range and responsiveness similar to that of a petrol engine – avoiding the time lag you sometimes get from a diesel engine.

The engine concept was invented by Formula One designer David Cox, founder of Cox Powertrain and developed with engineering consultancy Ricardo UK. It is based on a supercharged, two-stroke diesel opposed piston architecture, with Scotch Yoke crankshaft and a central injector position.