Leave it to Lotus to find the smallest, simplest solution to a problem. This one involves series hybrids, like the Chevrolet Volt, which have a gas engine on-board to power the car's electric drive motor when the battery pack lacks sufficient charge. This gas engine will never actually drive the wheels directly, so it doesn't need to be large, which is why we've always questioned why the Volt will have a 1.4-liter four-cylinder gas engine.
At the 2009 Frankfurt Auto Show next week, Lotus Engineering will show a 1.2-liter, SOHC, 2-valve-per-cylinder, all-aluminum three-cylinder engine developed expressly for series-hybrid use. It could power an electric motor or recharge a battery pack. You could put gasoline in it or use an alcohol-based fuel like ethanol.
The engine is tuned to provide 20 hp at 1,500 rpm via its built-in electrical generator, with a peak 47 hp at 3,500 rpm. Torque is rated 79 pound-feet at 2,500 rpm.
More important than the numbers, though, are the engine's potential packaging and cost advantages. Monoblock construction blends the engine block and cylinder head together, eliminating the need for a head gasket. This reduces weight -- Lotus says the 1.2-liter's dry weight is 123 lbs -- which is a key consideration in a car with heavy batteries. In addition, the cylinder head design integrates the exhaust manifold, which would save on manufacturing costs -- a key consideration in a car with expensive batteries.
IL News: 2009 Frankfurt Auto Show Preview: Lotus Range Extender Engine for Hybrids
estreka says:
06:04 PM, 09/ 9/09
I really like Lotus because they're so spartan when it comes to engineering.