The Mk1 transit V4 engine was a 60 degree V4 ohv made in two sizes. 1664 and 1996cc.The bore on each engine was the same at 93.67mm but strokes of 60.35 and 72.42mm gave the different capacities as a result the pistons and crankshafts are different on the two engines. Both engines were available in low compression form (7.7 to 1) and high 9.1 to 1 for the smaller unit and 8.9 to 1 for the larger. Power output varied from 73 bhp (Low compression 1.7) to 93 bhp on high compression 2.0 litre and torque from 100 lb/ft to 123.5.
The engines, known as the Essex were the basis for the 2.5 and 3 litre V6 engines which powered many Ford and other vehicles in the 70ís. The six cylinder engines (also called Essex) are basically the V4 with a couple of cylinders added. The V4 was used in the Corsair, Transit a few Capris and was occasionally used on transplants in other vehicles like the NSU rotary it was used f0r about ten years from 1964..The V4 and V6 engines known as the Cologne,fitted to german transits athough appearing similar,share no components with the Essex units.
Early (pre 1968) blocks were different to accomodate different oil pumps.The later pump has a flat cover.The blocks and pumps are not interchangeable.The valve gear is driven by a central camshaft, running in three replaceable bearings. The same shaft drove the distributor via a skew gear which in turn drove the oil pump via a long hexagonal shaft. This shaft was a known weakness in the design, an oil pump providing 50psi with thick cold oil needs quite a lot of torque to turn and the hex shaft could round off with wear. A fibre gear drives the camshaft at half engine speed, this gained a reputation for breaking especially at high revs, and was sometimes weakened after overheating. The mechanical fuel pump is operated by an eccentric bolted to the fibre timing gear. The engines are what is sometimes called interference, this means that if the drive to the camshaft breaks it is possible for the valves to hit the pistons. As these engines are inherently unbalanced an internal balance shaft turning at engine speed was used to try and reduce vibration, this is driven like the timing wheel by a helical gear on the front of the crankshaft. The balance shafts are of different designs on the two engines the 2000cc version being heavier.Despite these balance shafts the engines were considered rough running and probably did not help the sales of the Corsair which in its 2000E form was marketed as a fast luxury saloon. The 2000E used a twin choke Weber carburettor and a different induction manifold casting. The cylinder heads are cast iron with shallow combustion chambers compression ratios are varied by using different pistons. The engine was current for about twelve years from 1965, the clutch and flywheel were altered in July 68 but the early cover identified by its riveted construct is interchangeable with the later unit. In October 68 the oil pumps (either vane or bi-rotor type are fitted and are interchangeable) were up dated. The later units are identifiable by the bottom of the pump being a flat steel plate, they are not interchangeable with the earlier pumps.The pumps fit at a different height in the blocks so these too are non interchageable. At the same time the lubrication system to the main and big end bearings was improved. Either Ford or Lucas distributors were used.
Many pictures and exploded diagrams show the engine with a cylinder liner. These were not fitted as standard, the engine bores are machined in the block, liners are only used to repair damaged cylinders.Some engine blocks use main bearings which are oversized on their outside diameter (.015 inches), if this is the case the bearing shells should be marked as such.
Dismantling the engine is reasonably straight forward, the big end bolts benefit from using a six sided good quality socket (11mm) to avoid rounding the heads and care must be taken removing the easily damaged camshaft gear. The camshaft is withdrawn from the front of the engine and care is needed to ensure the lobes donít damage the bearings. A single nut adjusts the valves if this loses its self-locking abilities it can unscrew in service; renewal or the use of a second lock nut ensures this canít happen. Front and rear crankshaft oil seals are conventional, Ford used a special tool to centralise them but its possible to do them without.The front engine plate and the timing cover, both have gaskets, the rear plate does not. If refitting the oil pump with the engine in the vehicle care must be taken to ensure the drive shaft engages with the distributor,failure to do so will obviously result in no oil pressure. If changing the main bearing shells with the engine still fitted,the normal trick of using a short flat headed nail or similar placed in the oil hole to 'wind out' the old bearing doesn't work too well due to the angle of the oil way drillings. These engines are among the Ford engines that have bearings that may ary in their outside diameters,in addition to bearings designed to fit cranshafts with reground journals (normally in 10,20,30 etc undersize) bearing with the outside larger in increments of the same size are used.Care has to be taken to select the correct bearings or the engine will have no oil pressure.Using a piece of aluminium bent in a curve will normally move the old bearing enough so that it can be removed. The engine blocks were sometimes machined (line bored) to take bearings with a larger outside diameter than standard,fitting the wrong bearing obviously has a disastrous effect.The bearings and thrust washer arrangements are conventional. The bolt spacing of the flywheel is asymmetrical it can only fit in one position. Timing and balance gears are keyed and are marked with dots at the base of the teeth, the ignition timing is set via a pointer is cast on the timing cover and as notch cut in the crank pulley.The engine weighs in excess of 300 lbs.
Main torque settings are (lbs ft) Big ends 30, Main bearings 55-50, Flywheel 45-55, Cylinder head 65-70.
I accept no responsibility for mistakes in the above and welcome any comments