Products in the engine
Camshafts
Wear-resistant cams for long, powerful engine life
To withstand the high bending and torsion forces over the long term, the camshafts in the Motorservice product range have been designed to incorporate high strength properties. Camshafts may be cast or forged, depending on their intended purpose.
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Tecnipedia
Camshafts
The camshaft is driven by the crankshaft via the drive pulley and controls the valve train of the engine. The camshaft helps to ensure that the intake and exhaust valves open and close at a predetermined time. The duration of opening, valve stroke and movement when opening and closing are determined by the shape of the cam.
Overhead camshafts
Where camshafts are overhead, the valves are opened directly by the cams via the tappets, rocker arms or finger type rockers. Overhead camshafts are used only with multiple cylinder heads.
On engine designs that have two camshafts (DOHC), one shaft actuates the intake valves and the other shaft actuates the exhaust valves. To ensure maximum fill, the cam stroke of the intake camshaft is typically greater than the stroke of the outlet camshaft.
Bottom-mounted camshafts
Where camshafts are bottom-mounted, the tappets and valve push rods transfer the stroke of the camshaft to the rocker arms.
Combined camshafts
Three cams for PLD fuel injection systems:
- Intake cam
- Outlet cam
- Cam for driving the pumps or the pump nozzle units
Camshafts should always be replaced at the same time as their interacting sliding parts, to prevent damage due to wear on the interacting sliding parts. Motorservice can supply the associated valve actuating elements, such as tappets, rocker arms/finger type rockers and valve play compensating elements separately or as a kit with the corresponding camshaft.
Further information
Bottom-mounted camshafts
Where camshafts are bottom-mounted, the tappets and push rods transfer the stroke of the camshaft to the rocker arms. The rocker arms push open the valves against the force of the valve springs.
| 1 Valve-spring |
| 2 Valve |
| 3 Rocker arm |
| 4 Push rod |
| 5 Tappet |
| 6 Camshaft |
Camshaft accessories
- Camshafts should always be replaced at the same time as their interacting sliding parts, to prevent damage due to wear of the latter.
- The associated valve actuating elements (interacting sliding parts), such as tappets, rocker arms and hydraulic valve lifters, are available separately.