Technical characteristics of the valve timing mechanism (VW Passat B2)

The engine uses a valve timing mechanism with an overhead camshaft, the drive of which is carried out by a toothed belt from the crankshaft pulley. The belt tension is provided by an eccentric roller.

Camshaft

The camshaft has five bearings.

Maximum axial displacement of the camshaft with the tappets removed and bearing caps installed from 1st to 5th, mm: 0.15.

Radial runout of shaft journals, no more than, mm: 0.01.

The camshaft of EP and OT engines is marked with a blue belt applied between the first and second cams.

The spare parts are supplied as reground camshafts complete with bearings. In this case, the camshaft is marked with a yellow mark.
Camshaft journal diameter, mm:

• nominal: 26.00;
• repair size: 25.75.

Valve timing (with a calculated zero clearance between the camshaft cams and adjusting washers and a valve lift of 1 mm)



When the valve timing mechanism is installed correctly, the "O" mark, corresponding to the TDC of the end of the compression stroke of the piston of the 1st cylinder on the flywheel, should be aligned with the mark on the clutch housing, and the mark on the toothed pulley of the camshaft should be opposite the mark on the pulley of the intermediate shaft.

Intermediate shaft

The intermediate shaft is driven by a toothed belt from the crankshaft pulley. The intermediate shaft drives the fuel pump, ignition distributor and oil pump.

Intermediate shaft journal diameter, mm:

• front: 42.95;
• back: 41.95.

Timing Belt for Camshaft Drive

Brand and type: Pirelli 121 R 180 or Uniroyal Powergrip 41121.

The belt tension is considered normal if in the middle of the branch between the pulleys of the camshaft and intermediate shafts the belt is twisted no more than 90° by the force of the thumb and index finger.