Ford Essex V6 engine (UK)

History

The Essex V4 and V6 were mainly designed to replace the outdated and aging inline-four and six-cylinder Ford Zephyr engine. It was produced in four capacities: 2.5 L (2495 cc, 153 ci), 3.0 L (2994 cc, 183 ci), 3.1 L (3098 cc, 189 ci), 3.4 L (3412 cc, 207 ci), with the 3.0 litre version being the most common and widely used. These engines were fitted to a wide range of vehicles, from Ford Transit vans to sedans, coupés like the Ford Capri and sports cars like TVR and Marcos. The earlier versions of engine were rated at 128 hp ( 95 kW ) and 173 lb/ft of torque, around October 1971 the engine was revised by modifying the camshaft and cylinder heads that improved the power and torque to produce 157 SAE Hp or 138 DIN hp (103 kW) at 5000 rpm and 192 SAE lb/ft or 174 DIN lb/ft of torque at 3000 rpm. At the same time, the oil disptick was moved from the front of the engine to the side, the inlet manifold was improved from earlier models, and the compression ratio was raised slightly from 8.9:1 to 9.0:1 due to a change of the piston design. The shape of the inlet ports were also changed, from an O-port design to a D-port design which improved the flow characteristics of the heads, the old Weber 40 DFAV carburetor that was prone to over-fueling and resulting bore wash was replaced by the Weber 38 DGAS Carburetor, the air filter housing was also changed and later around 1976 and a hot air intake was added consisting of a metal pipe running from the top of a plate welded on the exhaust manifold or header to an opening in the air intake to prevent the carburetor from icing and making the engine warm up quicker, the carburetor was also modified again and a return style fuel system was adopted and a vacuum operated choke in the air filter housing were also added, this and a Positive crankcase ventilation (PCV) system were also early forms of emissions control. The camshaft gear was also made slightly stronger by using steel with nylon teeth instead of being completely made from nylon as on previous ones. Aftermarket steel, aluminium, and alloy gears have been produced as replacements to prevent the gear from stripping its teeth: this is commonly due to overheating causing the nylon to weaken. This is one of the two major "weak points" of the Essex vee-engines with the other being the hexagonal oil pump spindle / shaft which can round off or even break. Such breakage is likely due to the fact that the oil grade specified for the Essex V4 and V6 is 20W-40 or 20W-50 which can become very viscous in extremely cold temperatures and places a very high stress on the shaft.

The 2.5 L engine was rated at 137 hp (102 kW; 139 PS) SAE, 120 hp (89 kW; 122 PS) DIN, torque was rated a 145 SAE lb/ft or 132 DIN lb/ft. The 2.5-litre version ended production in 1977 along with the Essex V4 engine. The 3.1 L engine as used in the Ford Capri RS 3100 was essentially a 3.0 L engine bored out by 1.6 mm or 60 thousands of an inch from 93.6 mm (3.69 inches) to 95.2 mm (3.75 inches). It was capable of 148 hp and 188 lb/ft of torque. It featured blue rocker covers in order to distinguish the engine from the usual 3.0 L engine and it also featured hand polished and ported inlet and exhaust ports, Only 250 RS 3100s were produced for homologation purposes between November 1973 and January 1974, making original 3.1 litre engines very rare, although modified engines bored +0.60 are common, one of the first 50 engines which was in a RS 3100 that was free for car magazines to review and test in fact had 165 Hp instead of the 148 of the rest of road going RS 3100s, this was achieved with a higher lift camshaft. These figures vary somewhat depending on the source.
The Essex V6 also formed the base for the 3.4 L Cosworth GAA born in May 1972 and designed by Mike Hall, also responsible for designing Cosworth's famous DFV Engine the GAA with the benefit of 100mm bores, DOHC aluminium alloy heads, Lucas mechanical fuel injection, a dry sump oiling system and a steel crankshaft generated 462 bhp (345 kW; 468 PS) at 9000 rpm and 300 ft/lb of torque, Mike Hall's intention was to design the cylinder heads so that 3 spark plugs per cylinder could be fitted but this idea was dropped since there wasn't any appreciatable increase in power or torque, the original objective was an engine with a minimum of 400 Hp, this objective was exceeded with the engine making 420 Hp in the first test run. This engine was used in the racing version of the Capri RS 3100, competing successfully in the European Touring Car Championship, as well as in Formula 5000 single-seaters. 100 kits were also sold by Ford Motorsport.

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Ford RS Dealerships also offered a number of performance modifications for the Essex V6 called the GP1 and X Pack, the GP1 package offered a Weber 40 DFI5 Carburetor a camshaft kit, larger 44.5mm inlet and 41.3mm exhaust valves, double valve springs, "specially selected" connecting rods and forged high compression pistons giving a power output of around 170 Hp, the X pack offered the same larger inlet and exhaust valves as the GP1 but also offered a new inlet manifold designed for 3 Weber 42 DCNF Carburetors, nicknamed as the "Triple Weber manifold" which boosted power up to 185 Hp and 195 lb/ft which was fitted as standard on the Series X Capris made from 1977 to 1981.

Earlier versions of the 3.0 litre engine ( pre October 1971 ) were fueled by a Weber 40 DFAV Twin choke carburetor, which had some inherent faults in its design which caused it to run too rich and cause bore wash. It was subsequently replaced by a more modern Weber 38 DGAS twin choke carburetor which effectively solved the problems of the earlier carburetors, and was used for the 3 Litre V6 until the end of its production. The 2.5 litre V6 used a single barrel Ford carburetor which was also used in the low compression variants of the 3.0 litre Essex V6 used in the Ford Transit. Unusually, the Essex V6 was designed so that the same block could serve in both diesel (compression ignition) and petrol applications, although the diesel version never reached production. Traces of its diesel design lie in the very heavy construction using Heron cylinder heads and the necessity for dished pistons to decrease compression for the petrol engine. The cast iron Essex V6 is a heavy engine due to its sturdy design weighing in at 170 kg or 374 pounds, 56 pounds more than the aluminum alloy Rover V8, for example, the Essex V6 also has a very heavy yet sturdy four-main bearing crossplane crankshaft with large 63.52mm (2.50 in) main journals, and a heavy flywheel in order to smooth out the power delivery, sometimes Essex V6 engines are referred to as an "Essex Lump" referring to the weight of these engines. In spite of its heaviness, the Essex V6 was used as the main workhorse and a high performance option for medium to full-sized cars like the Capri the Granada and Transit vans supplied by Ford to the Police and Ambulance services in the UK throughout the late 1960s and 1970s and up until 1989 in the case of the Transit where it was later replaced by more modern engines such as the fuel injected 2.8 and 2.9 L Ford Cologne V6 engine and was even used until April 2000 in South Africa.

TVR contracted the company Broadspeed to develop a turbocharging system for their TVR 3000S Turbo. In lieu of fuel injection, the carburettor was run inside a pressurized box atop the engine, and the turbocharger itself was mounted low and forward in the engine compartment, requiring the exhaust manifolds to exit forward. The compression ratio was lowered from 9.0:1 to 8.0:1 to reduce the engine's internal stresses. Turbocharging substantially increased horsepower, from 138 hp to 230 (103 to 172 kW) and torque from 182 lb/ft to 273 lb/ft.

Broadspeed also designed a turbocharging system For the Mk1 Ford Capri 3.0, available since early 1970 these Capris were known as Broadspeed Bullett Capris, the engine was heavily modified and included modified cylinder heads, a high lift camshaft, a re jetted carburetor, a completely blueprinted rotating assembly, lowered 8.2:1 compression ratio, a modified inlet manifold and exhaust system using a single turbocharger. Their power was substantially increased (by 63%) from 138 hp to 218 hp. Similar to the TVR 3000S' turbocharging system, it used a "Blow through Carburetor" system in which the standard but re-jetted Weber 38 DGAS carburetor was run inside a pressurized box, performance figures further increased with the uprated post-October 1971 versions of the engine. The company Janspeed, well known for their high performance exhaust systems also designed a turbocharging system for the Ford Essex 3.0 L and 1.6 - 2.0 L OHC engines, although these were much simpler than the turbocharging system offered by Broadspeed, Janspeed promised a 25% increase in horsepower boosting the engine's power output from 138 to around 172 Hp using a single Roto-Master turbocharger mounted directly on top of the left bank of the engine providing 5 psi of boost.

The 2.5 L and 3.0 L engines share the same block, connecting rods and 93.66 mm (3.7 in) bore, differing only in crank throw and pistons, 3.0 L pistons have a length of 95mm and 2.5 L pistons have a length of 100 / 101mm .

Companies like Specialised Engines, Essex engines and Ric Wood have professionally built and developed large displacement 3.2 L, 3.4 L and even 4.0 L Conversions and forced induction conversions for the Essex V6 with power outputs reaching as high as 390 Hp.

US emissions certification

In 1977, Californian company Olson Engineering, Inc. was contracted by TVR to design modifications to the Essex V6 such that it could be emissions-certified for use in the United States. This allowed TVR to sell its Essex-engined M Series cars in that market for the 1978 and 1979 model years. An owner's handbook supplement for US Federal models indicates that the emissions control system used a catalytic converter, exhaust gas recirculation, and secondary air injection. A shipment of approximately twenty 3000Ss arrived in September 1979, and were marked by the import company as being emissions compliant without the Olson Engineering emissions kit actually having been fitted. Dealers were made aware of this fact, but were each apparently coerced into buying at least two of the non-compliant cars with the threat of withholding spare parts for other TVR models. One dealer explained the situation to a customer who happened to work for the US government in an emissions-regulation capacity, and he reported the violation to the authorities. The cars were then impounded. During the long period of time during which Martin Lilley attempted to communicate with US customs officials to resolve the situation, the cars were neglected and stored outside, where they deteriorated and were vandalized. The cars were eventually re-exported, repaired, and sold in Germany, but the short-term financial impact of the unsalable cars (worth over £100,000 in total) was damaging to the development of the M Series replacement, the Tasmin.

South Africa

In South Africa, the engine continued in production from 1982 up to April 2000 for use in the Sapphire Saloon and Sierra vehicles, and Courier pick-ups. Late in its production life it was fitted with Lucas controlled electronic fuel injection designed by SAMCOR (South African Motor Corporation - now Ford SA) in co-operation with the University of Pretoria's engineering department. This conversion resulted in a power increase from 103 kW (140 PS; 138 bhp) to 110 kW (150 PS; 148 bhp) of the standard 3.0 version, and 117 kW (159 PS; 157 bhp) for the fuel injection version, plus a useful boost to fuel economy. Only about 1,600 of the EFI variants were produced during 1992 and 1993. In October 1997, the 3.0L was enlarged to 3.4L by boring the cylinders .040 of an inch or 1mm to 94.6mm and a new crankshaft with a stroke of 80.0mm giving a displacement of 3375cc, this was done for the engine to be better suited to 4x4 vehicles where torque is needed. The 3.4 version produced 108 kW (147 PS; 145 bhp) and 260 N·m (190 lb·ft). All 3.4 variants used the 38DGAS Weber carburetor with 29 mm (1.1 in) venturis. Production tooling at the factory was scrapped and sold in 2000, to make way for the production of a new four cylinder OHC engine, the remaining old stock of 3.4 L Engines started to be sold as assembled crate engines, these engines had some differences from the 2.5 3.0 and 3.1 L Dagenham built engines such as: Ford Cologne 2.8 / 2.9 V6 forged connecting rods, German made pistons with moly coating, .250" smaller crank journals which reduced bearing speed, more aggressive camshaft timing and higher lift,larger 43mm inlet valves, shaft mounted rockers from Ford's Cologne 2.8 / 2.9 V6 engine, unique cylinder head castings with extra oil galleries, solid pushrods with no oiling holes, unique exhaust manifold bolt pattern due to the head castings also being unique to the 3.4 litre engine and an improved inlet manifold with larger runners and an improved plenum chamber. From 1966 to 1998, the 3.0L was also used in industrial applications such as generator plants, airport vehicles, milk vans, jet boats (Hamilton jet) and even river barges.

Vehicles using the Essex V6

The Essex V6 was fitted to a wide variety of cars, both from Ford and from smaller specialist manufacturers that used Ford engines. Among these were the following:

United Kingdom

South Africa

Netherlands