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You remember the Lotus Omnivore project don’t you? We first heard word of this project back in August 2008 and Lotus exhibited a concept engine at the Geneva show earlier this year. It’s basically a monoblock (integrated block and head) engine that runs on a two-stroke operating cycle that Lotus says is more suited to flex-fuel operations than conventional 4-stroke engines.

There is a whole load of tech packed into the Omnivore. Other than being unusually 2-stroke in a world of 4-stroke car engines, its got variable compression ratio, direct fuel injection, and the ability to run on HCCI mode, which is basically diesel-like sparkless ignition, except that it isn’t a diesel engine.


“The automotive industry, including Lotus Engineering, has quite rightly advocated engine downsizing for four-stroke engines. This is as a result of the dominance of the four-stroke cycle in the automotive world and its generation of throttling losses at part-load, where vehicles run most of the time,” says Jamie Turner, Lotus Engineering chief engineer of powertrain research.

“The two-stroke cycle, conversely, does not suffer from significant throttling losses and in many ways is a more natural fit for automotive use. With the thermodynamic disadvantages of throttling losses removed, the two-stroke engine is free to be sized according to its improved part-load fuel consumption. Downsizing therefore isn’t vital and, due to the improved light-load efficiency and emissions performance we see with Omnivore, this technology approach and ‘upsizing’ could permit a more efficient engine,” adds Turner.

Look after the jump for a 6 page detailed technical description of the Omnivore.