

Jacobs Vehicle Systems has launched a component to allow heavy-duty engines to benefit from stop-start technology.
The Active Decompression Technology (ADT) (right) eliminates engine-shake at start-up and shut-down, as well as improving fuel economy and reducing emissions. The ADT is automatically activated by the ECU and works by keeping the engine valves open and the cylinders decompressed. This enables a smooth shutdown, and when starting up the engine is kept decompressed to reduce torque and allow the engine to spin up to twice as fast.
This increases the speed at which the fuel system is primed and decreases wear and tear on the starting gear.
The system is said to reduce engine shake during shutdown by as much as 90% and is particularly useful when automatic starting is required to maintain a battery charge – particularly if there is a driver asleep in the cab.
By enabling the engine to be turned over while decompressed, the system also improves cold weather starting.
Jacobs Vehicle Systems vice president of engineering and business development Steve Ernest said: “ADT is another development of Jacobs’ well-proven valve actuation technologies. ADT enhances vehicle refinement by eliminating engine and cabin-shake. Customers – particularly those whose vehicles endure heavy stop-start cycles – will welcome the reduced component load, fuel economy and emissions advantages.”