Technical characteristics of the gas distribution mechanism

The engine uses a valve timing mechanism with an overhead camshaft, which is driven by a toothed belt from the crankshaft toothed pulley. The belt tension is adjusted mechanically by turning the water pump housing.

The toothed pulleys of the crankshaft and camshaft are mounted on segment keys.

Camshaft

Three-bearing camshaft. A hole is made in the rear end of the shaft for driving the ignition distributor. Between the cams of the 2nd and 3rd cylinders, there are two influxes on the shaft.

Shaft marking: FZ.

Diameter of camshaft journals, mm:

• front: 31.45;
• average: 39.45;
• rear: 40.45.

Radial runout of the middle neck of the shaft, no more than, mm: 0.01.

Valve timing*

• The beginning of the opening of the intake valve to the TDC of the exhaust stroke with the lead: 3°.
• Closing of the inlet valve after the BDC of the compression stroke with a delay: 46°.
• The beginning of the opening of the exhaust valve to the BDC of the working stroke ahead of: 47°.
• Closing of the final valve after TDC of a step of release with delay: 7°.

* With a calculated zero clearance between the camshaft lobes and levers, and a valve lift of 1 mm.

When the timing is correctly set, the mark on the crankshaft pulley should be aligned with the pointer on the cylinder block, and the mark on the camshaft sprocket should be aligned with the setting plate on the cylinder head.

Toothed belt

Make and type: Goodyear GYO 67.

Belt tension is adjusted by turning the water pump housing.