OHV engines The 1.1 litre and 1.3 litre OHV engines are of four-cylinder, in-line overhead valve type (hence OHV), mounted transversely together with the transmission, at the front of the car.

The crankshaft on 1.1 litre engines is supported in three shell type main bearings, whereas the 1.3 litre unit features a five main bearing crankshaft. Apart from this difference and other minor alterations, the two engines are virtually the same in design and construction.

The connecting rods are attached to the crankshaft by horizontally split shell type bigend bearings and to the pistons by interference fit gudgeon pins. The aluminium alloy pistons are of the slipper type and are fitted with three piston rings; two compression and one oil control.

The camshaft is chain driven from the crankshaft and operates the valves via pushrods and rocker arms. The inlet and exhaust valves are each closed by a single valve spring and operate in guides integral with the cylinder head. The oil pump and distributor are driven by a skew gear on the camshaft while an eccentric cam operates the fuel pump lever.

The oil pump is mounted externally on the cylinder block just below the distributor, and the full flow type oil filter is screwed directly into the oil pump. Engine oil contained in the sump is drawn through a strainer and pick-up tube by an externally mounted oil pump of twin rotor design. The oil is then forced through the full-flow, throw-away type oil filter. Oil pressure is regulated by a relief valve integral in the oil pump. The pressurised oil is directed through the various galleries and passages to all bearing surfaces. A drilling in the big-end provides lubrication for the gudgeon pins and cylinder bores. The timing chain and sprockets are lubricated by an oil ejection nozzle.

HCS engines
The 1.1 and 1.3 litre High Compression Swirl (HCS) engines were introduced at the beginning of 1989 and fitted to certain 1.1 Escort models and all 1.3 Escort models, including the Van and Combi, replacing the previous OHV engine.

A further development of the Ford “lean burn” principle, the HCS engine is basically similar to the previous OHV engine, being of four cylinder, in-line OHV construction, but nearly every aspect of the engine has been redesigned.

The major differences are in the cylinder head, where the inlet valve ports and combustion chambers are designed to impart a high level of “swirl” to the incoming fuel/air mixture. The valve arrangement is also different, being of “mirror” design, where the inlet valves of the centre cylinders are next to each other. Combined with the DIS fully

1.1 Cutaway view of the 1.1 litre OHV engine

electronic ignition system which has no moving parts, the result is an economical engine with cleaner exhaust emissions which can run on leaded or unleaded fuel without adjustment to the ignition system.

Although most components of the HCS engine have been redesigned, for the most part the servicing and overhaul procedures remain unchanged, unless otherwise stated.