SOHC engines

General information

The engine is of a four-cylinder, in-line, single overhead camshaft type, mounted at the front of the vehicle and available in 1.3, 1.6, 1.8 and 2.0 litre versions.

The crankshaft incorporates five main bearings. Thrustwashers are fitted to the centre main bearing in order to control crankshaft endfloat.

The camshaft is driven by a toothed belt and operates the slightly angled valves via cam followers which pivot on ball-pins.

The auxiliary shaft which is also driven by the toothed belt, drives the distributor, oil pump and fuel pump.

The cylinder head is of crossflow design with the inlet manifold mounted on the lefthand side and the exhaust manifold mounted on the right-hand side.

Lubrication is by means of a bi-rotor pump which draws oil through a strainer located inside the sump, and forces it through a fullflow filter into the engine oil galleries where it is distributed to the crankshaft, camshaft and auxiliary shaft. The big-end bearings are supplied with oil via internal drillings in the crankshaft. The undersides of the pistons are supplied with oil from drillings in the big-ends.

The distributor shaft is intermittently supplied with oil from the drilled auxiliary shaft. The camshaft followers are supplied with oil via a drilled spray tube from the centre camshaft bearing.

A semi-closed crankcase ventilation system is employed whereby piston blow-by gases are drawn into the inlet manifold via an oil separator and control valve.

Engine oil and filter - renewal

Refer to Chapter 1, Section 8.

Valve clearances - checking and adjustment

Refer to Chapter 1, Section 23.

Crankcase ventilation system - inspection and maintenance

Refer to Chapter 1, Section 35.

See also:

Camshaft - removal and refitting
Carburettor engines Note: Thread locking compound will be required to coat the camshaft sprocket bolt on refitting. Removal 1 Disconnect the battery negative lead. 2 Refer to the relevant Part o ...

Radiator - removal, inspection and refitting
All models except RS Turbo Pre-1986 models Removal 1 Drain the cooling system as described in Chapter 1. 2 Disconnect the battery negative terminal. 3 Release the retaining clips and disconnect ...

Fuses, relays and circuit breakers - general information
Pre-1986 models 1 The fuses and most of the relays are located in a plastic box attached to the bulkhead on the driver’s side of the engine compartment. 2 The fuses are numbered to identify the ...

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