Federal-Mogul Powertrain, a US-headquartered global designer and manufacturer of original equipment powertrain components and systems protection products, will launch a new, smaller version of its proven Rotocap® valve rotator, the first for 4 valve per cylinder light vehicle engines, at this year´s IAA in Frankfurt, Germany. It has application for alt-fuel vehicles, including NGVs.
The miniaturized design features an outer diameter in the range of 20-25 mm and allows the Rotocap to package into the valve assembly on automotive powertrains. Rotocap provides the enhanced valve rotation control required to compensate the challenges caused by reduced valvetrain lubrication and engine downspeeding – two main design trends to achieve lower emissions and improve fuel efficiency.
Rotocap eliminates uncontrolled rotation which normally – by torsion of the valve spring or by miscellaneous resonances – is transferred to the valve during its opening and closing movement. It is replaced with motion through a defined angular movement that only takes place as the valve opens – this controlled movement can be relied upon across the whole engine speed range. Rotocaps also reduce abrasive wear of the valve seat area because the valve no longer rotates as it closes. This is particularly beneficial on engines designed with reduced oil consumption on the valvetrain or engines using alternative fuels such as Compressed Natural Gas (CNG) with generally higher seat wear ratios than gasoline or diesel.
Valve rotation ensures an even distribution of temperature around the seat, increasing durability by reducing local distortion and avoiding blow-by and crack formation across the sealing surface. In addition, rotation reduces wear on other components in direct contact with the valve.
Source: Federal Mogul Powertrain