Engine mechanics

Cylinder block

The weight of the cylinder block has been reduced by approx. 6kg compared with the 2.0l 103kW TDI engine thanks to various measures. This includes the omission of:

• Bolting points,
• ribs and
• various unnecessary mounts.

The reduced displacement has been achieved with a smaller cylinder diameter and a shorter stroke. The cylinder diameter is 79.5mm. The stroke of 80.5mm is achieved with smaller diameter crank pins on the crank shaft.

Piston

The piston is a die-cast part made from aluminium. The shape of the piston recess allows good fuel swirl generation and improves the mixture formation. The piston bushing could be omitted due to the lower thermal loading.

Cylinder head

The cylinder head on the 1.6l TDI engine with common rail injection system has two inlet valves and two exhaust valves for each cylinder. The camshafts are driven by the crankshaft via a toothed belt and the spur gear teeth. An oval exhaust gas port and a spiral-shaped intake port allows a faster gas flow. This contributes to a better mixture formation. The valves are actuated by roller rocker fingers with hydraulic valve play compensation.

Cylinder head cover

The cylinder head cover has two outer clamping pieces for securing the injectors. The seals for the injectors are in the cylinder head cover.

Toothed belt drive

The camshaft, the high-pressure pump for the common rail system and the coolant pump are driven by the toothed belt. The width of the toothed belt has been reduced by 5mm to 25mm and all sprockets, belt tensioners and guide rollers have been modified accordingly.

Ancillary component drive

The ancillary components are driven via a flexible, stretchable poly V-belt, called a flexi belt. The belt tensioner is not required due to the use of the flexi belt. There are two different versions:

1. Poly V-belt drive for vehicles without air-conditioning compressor.

Only the alternator is driven by the poly V-belt in this case.

2. Poly V-belt drive for vehicles with air-conditioning compressor.

All ancillary units are driven by a poly V-belt with guide roller.