When it comes to shedding weight of a car, most changes are made to the exterior panels and this is where carbon fibre comes into the picture. Yes, it helps, but the engines are still the heavy weighing in at close to 100 odd kilos. But even engines have lost weight and it is thanks to aluminium alloys particularly in cylinder blocks and crankcases that the engine manages to retain the balance in a car and also help in weight distribution.
But now, there’s something else brewing in the world of lightweight engines. There’s one that is mostly made from plastic and will be tested in a racing car in 2016. US engineer Matti Holtzberg has teamed up with Belgian chemical company Solvay to work on the Polimotor 2 project which will see the birth of a powerful plastic engine.
Holtzberg, the president of Florida-based Composite Castings, had success with his first Polimotor engines in 1982, when they were used in an Amoco Chemical Company-sponsored racing car. The engine was based on a 2.0-litre Cosworth BDA engine which churned out 290bhp. There were plastic parts in this engine and these were the engine block, cam cover, intake valve stems, piston skirts, valve spring retainers, timing gears among others. Thanks to these components, the engine weighed in at 84 kg, which was half the weight when compared to the one with metal parts.
The Polimotor 2 takes things to a new level altogether. The engine is a four-cylinder, double-overhead CAM and will be installed in a Norma M-20 concept car which will compete at Lime Rock Park, Connecticut.
All that said, onto the big questions – Plastic in an Engine? How safe is it? Will it melt? Well no, it won’t because certain components are made out of plastic. The exhaust port and the combustion chamber is an aluminium casting that’s moulded into the cylinder head and then the pistons run in either a cast iron or a nikasil-coated bore. So, there is metal where the heat is; the rest is made out of composite material.
Solvay will provide up to 10 thermoplastic components which will replace the metal parts and these include the water pump, oil pump, water inlet/outlet, throttle body, fuel rail and cam sprockets. The engine will also feature a plastic turbocharger and an improved fuel injection system. Yes, it’ll be powerful and will be capable of churning out 450bhp at 8000 rpm.
The entire development will be aimed at making an engine that weighs just about 63-67kg. There is still a lot of happening on the engine front and there are a number of technical issues to overcome, but if everything goes according to plan, this could very clearly be the future of engines.