Paper 3: The Design History of Ford of England'S 1000 cm 3 −1500 cm 3 Engine Family

Abstract

This paper covers the design history of an engine family which originally spanned a capacity range of 1000–1390 cm³ but has lately been extended to 1500 cm³.

The requirements which governed the basic engine design are dealt with from two angles—the vehicle requirements, which determined the cylinder capacity and arrangement and led to the adoption of a water-cooled four-stroke design; and the production requirements, which dictated the need for a ‘family’ concept to give the maximum range of engine capacity from a single tooling set up. Performance, package and durability targets were established and it was essential to meet these while maintaining minimum cost and weight.

The layout of the basic engine provides for changes of capacity by variation of the stroke only; the advantage of this method over varying the bore or both bore and stroke is discussed from both product and manufacturing viewpoints. The engines are considerably ‘oversquare’ (large bores, short strokes) and the effect of this and the importance of connecting rod length to crank throw ratio is discussed.

The detail design of the cylinder block was influenced by the short stroke and resulted in equally spaced cylinder centres and main bearings of ample capacity being incorporated. A unique treatment of the push rod ‘chamber’ was adopted to eliminate coring.

The cylinder head has individual ports and fully machined combustion chambers with vertical valves and this layout made possible a single piece water jacket core. For the crankshaft, a hollow nodular iron casting was chosen and the very short strokes enabled balance weights to be omitted without bearing loads exceeding the limits of modem materials.

In laying out the ancillary components an unusual arrangement for the oil pump and filter was chosen with advantages of easy assembly and servicing.

After production of the engine family had commenced in 1000 cm³ and 1340 cm³ versions, the need for a 1500 cm³ version arose. This was achieved within the basic framework of the original design by a further increase of stroke, but required some increase of cylinder block height to maintain a reasonable connecting rod length.

Production tooling was fortunately able to accommodate this change and because of the equal bore and bearing spacing in the original design, it was possible to incorporate five main bearings.