Titanium
It has been reported that connecting rods have been forged out of titanium for
racing engines. The steel die is sprayed with a MoS2 coating to prevent oxidation of the
titanium during the forging process. While the cost of titanium is prohibitive for mass
production, it has been reported that Honda has been able to achieve an additional
700rpm engine speed with titanium connecting rods. Many Formula 1 race cars
utilize titanium connecting rods to achieve their 18,000 rpm engine speeds
Polymeric Materials
A hybrid connecting rod, developed under advanced composited program of
Daimler-Benz (Germany), consists of a carbon fiber reinforced plastic shank section with
titanium ends. These rods are reportedly 30% lighter than forged steel rods and have
successfully withstood maximum loading tests as would be experienced by 2.3L engine
at room temperature air and in oil at 120oC[12].