Plastic car engine could create lighter cars, better gas mileage

When it comes to cars, lightening the load can increase performance capabilities and fuel economy. Incorporating plastic components into the body of the car can only cut down the weight so much. So, auto makers are scrambling to find ways to use plastic parts in other components of the car. German research group Fraunhofer has found a way to create a car engine using plastic parts. Sure the pistons need to be metal, but the casing that houses the cylinders can be made of plastic. Fraunhofer's plastic casing weighs 20% less than if it were made using standard aluminum, and a little goes a long way when it comes to performance and saving fuel.

Plastics has been pursued as engine parts before, in the 1980s, but there were many hurdles to developing the technology including costs. It was simply to expensive to mass produce plastic engine parts back then.

Plastics and heat from an engine capable of thousands of rpm still sound like a bad combination, but Fraunhofer developed a way to create an injected-molded plastic engine housing that can withstand high temperatures, pressure, and vibrations without losing strength.

Fraunhofer altered the engine geometry, and reinforced the stress-prone areas of the engine with metal. Interestingly, the designers had to find a way to make sure the plastic could expand and contract at the same rate as the surrounding metal.

There are still some metal components in this new engine model, but the bulk of it is made with fiber-reinforced plastic. This technology is can be manufactured at the same cost as if it used standard metal housing. The research team intends to delve further into plastic engine design and create a multi-cylinder engine complete with plastic crankshaft bearings.

Via: Gizmag