Honsel components for legendary “muscle car”:
Engine block with innovative cylinder bore coatings for Ford Mustang Shelby
Honsel is supplying the aluminum engine block for the new Ford Mustang Shelby GT 500. Ford presented the latest version of the legendary “muscle car” at the Chicago Auto Show in February 2010. At 550 bhp, this extremely powerful V8 power unit places high demands on the engine components. So Honsel is coating the aluminum cylinder bores in an innovative plasma process for the first time. The steel coating thus generated is extremely robust. As it also reduces the friction, it makes the new Ford engine more economical and lowers the emissions.
Thanks to the new plasma coating in steel developed by Honsel, the pistons can run directly into the cylinders. That supersedes the need for the steel or cast iron linings that must be cast or shrunk into the aluminium cylinder housing of conventionally produced engines to reduce piston friction and wear.
“The new steel coating of the cylinder bores is extremely thin. It conducts the heat from the combustion chambers into the coolant much better than is possible with the necessarily thick cast-iron cylinder linings. Especially with a supercharged, high-performance engine like the new Shelby power unit that is important because of the high heat amount that needs to be dissipated in a very short time,” explains Dr. Bernhard Gand, Head of Engine Development at Honsel. In addition, the engines are more than four kilograms lighter because coated cylinder bores weigh a lot less than cast linings in steel or cast iron. “Another advantage is the result of the lowfriction and extremely resilient coating surface. Not only does it reduce the friction and thus the fuel consumption, but it also shows no wear whatsoever during the engine’s service life and provides for low engine oil consumption,” adds Dr. Gand.
Honsel has developed the coating method further based on the PTWA technology (Plasma Transferred Wire Arc). It can be combined with all casting methods for aluminum engine blocks. As the components of the Shelby power unit are subjected to very strong loads in operation, Honsel is producing the engine block in its patented low-pressure sand casting process. Before the actual coating, the cylinder bores are machined in an also Honsel patented process developed specially for that purpose. That activates the surfaces and provides optimum adhesion for the coating. A computer-controlled machine then runs down the cylinder bores and coats the surfaces with molten steel from a plasma particle jet. The coating then only needs to be worked down to the required residual coat thickness and highly polished.
This innovation from Honsel can be used universally in all petrol and diesel engines. High-performance engines like the Shelby power unit, or relatively small but heavily loaded downsized engines, benefit thereby from the excellent technological properties of the coating, and large series engines for volume models profit from the particular cost-effectiveness of the process”, says Dr. Gand, summarizing the advantages of the development. Besides Ford, other automotive manufacturers plan to use the innovative lining technology from Honsel in the future, many of them in engines for volume models.