As Honda and its partner teams, Lucky Strike BAR Honda and Benson and Hedges Jordan Honda, move to Budapest for the Hungarian Grand Prix after a three-week break from the racetrack, the everyday challenge of technological development has continued...
As Honda and its partner teams, Lucky Strike BAR Honda and Benson and Hedges Jordan Honda, move to Budapest for the Hungarian Grand Prix after a three-week break from the racetrack, the everyday challenge of technological development has continued behind the scenes for the engine manufacturer. Just one of the many areas that form this challenge is materials. When one considers the forces and temperatures created in a contemporary Formula One engine, it is evident that the materials needed in its construction have to be carefully researched and selected.
Honda, the world’s largest engine manufacturer, views its technical activities in Formula One as a sound test bed for its wider automotive business. Honda F1 engineers routinely pass the data they collect on the performance of materials in the cutting-edge environment of F1 to their colleagues in the parent road vehicle department at Honda’s R&D centre at Tochigi, outside Tokyo. The overriding consideration when choosing materials for an F1 engine is the ratio of weight-to-stiffness-to-strength. Striking the critical balance between minimum weight, maximum stiffness and high strength is fundamental to the optimum design and manufacture of the power unit. Each material is carefully selected according to the function of the part.
The principal metals employed in the construction of a Formula One engine are aluminium, magnesium, titanium and steel alloys, albeit in a specialised format, while other materials, such as carbon composites and ceramics, feature to a lesser extent. Aluminium is the most common material and its inherent stiffness means that all the major components such as the cylinder head, cylinder block and the pistons are built from it. Many of these components are constructed from special aluminium alloys such as Metal Matrix Composite (MMC), an advanced material which is starting to be adopted in F1. An added benefit of using aluminium is its excellent heat transfer characteristics, resulting in the heat generated within the engine being moved to the exterior quickly and dispersed efficiently Magnesium is lighter than aluminium but has less stiffness and is used in parts such as the cam covers, while the connecting rods (between the piston and the crankshaft) are made of titanium as well as some parts of the valvetrain. Although it is slightly heavier than aluminium, titanium is significantly stiffer. Steel alloys (composed of several metals eg. nickel and chromium) are used for the crankshaft, as the high-energy component requires a high-strength specialist material. Although carbon composite is a staple material in chassis construction, it has limited application in an engine, most visibly on the coil covers.
The lightness and insulating qualities of ceramic mean that it has wider benefits but its relative fragility means that it is still very difficult to apply to an F1 engine. Some manufacturers use it as a coating in the exhaust ports to prevent heat transfer from the exhaust gases to the cylinder heads, while several teams use a ceramic coating on the exhaust pipes. The exhaust system itself is made from inconel, a special nickel-zinc-chromium alloy developed for the casings of aero engines. It is a very thin and light metal but extremely stable at high operating temperatures, around 800-900 degrees Celsius, and during the rapid heating and cooling process an exhaust undergoes on an F1 car.
Some of the advances in both F1 and road car engine technology in the near future are likely to come from the introduction of more advanced and sophisticated materials and Honda, like many manufacturers, has a full-time team of engineers on its F1 project dedicated to the research of new materials, an area of continuing importance in research and development which requires substantial investment.