Ford CHT engine

The Ford CHT engine is an internal combustion inline-four engine produced by the Ford Motor Company in Brazil during the 1980s and 1990s. It is unrelated to the similarly-named CVH engine.

The CHT (Compound High Turbulence) was introduced in 1984 in the Mark 3 version of the Ford Escort, the first of the series to be released in Brazil.^[1] It was later used in the Ford Del Rey and the Ford Verona (a Brazilian Ford Orion), as well as the Volkswagen Gol.

This engine was based on the Renault Cléon-Fonte engine introduced in 1962. Ford do Brasil inherited this engine upon buying the Brazilian Willys/Renault operation in the late 1960s. It has a total of eight overhead valves, and features a rotating valve design. The displacement of the original Cléon-Fonte used in the Ford Corcel was 1,289 cc (73x77 mm bore and stroke); this was later raised to 1,372 cc (75.32x77 mm) for the "XP" engine, later called "1300-B" in single-carburetted form.^[2] The Cléon-Fonte was finally increased to 1,555 cc (77x83.5 mm) in 1979, a displacement which the CHT would inherit. Ford do Brasil used the Cléon-Fonte engine until 1983, when they made a thorough redesign to the head and renamed it CHT. The Corcel-derived Ford Pampa pickup truck also used the Cléon-Fonte engine until replaced with the CHT in 1984.

The goal of the redesign was to create an internal turbulence inside the piston chambers to promote more complete combustion. The resulting unit was robust and economical, albeit with modest performance when compared to the competing Volkswagen EA-827. The CHT has lower peak power but with generally higher average torque, with the torque curve being much straighter and closer to the maximum at any engine speed than a similar AP engine. Torque was the CHT engine's advantage, it being capable of running without much loss of power in very low engine speeds as well.

It was also available to run on Ethanol, which usually generates at least 10% more power than a corresponding petrol model, with a circa 25% increase to fuel consumption. It had no problems at all for cold starts and high fuel consumption unlike other early ethanol-powered engines.

Three models were originally available:

• 1.6 petrol (65 hp)
• 1.6 Ethanol (74 hp)
• 1.6 XR Ethanol (83 hp) for the Escort XR3

Later, the engine was tuned for better power figures and fuel efficiency:

• 1.6 petrol (74 hp)
• 1.6 Ethanol (86 hp)

In 1987, with the release of the Mark 4 Ford Escort, this engine benefited from some revisions, resulting in the CHT E-Max (maximised economy) version. All the new models featured better torque. This, the second generation CHT engine received the award of most economical engine of its time in Brazil, capable of running 17.1 km with one liter of petrol.

In 1992, a smaller version was released for the Escort and the Gol:

• 1.0 petrol (50 hp)

During the Autolatina period (1987–1996) VW used this engine, naming it AE-1600 and AE-1000 when fitted to VWs - but this is largely the same engine. AE stands for Alta Economia (High Economy). In 1996 and 1997 the CHT was gradually replaced by the Volkswagen EA-827 and the new Volkswagen EA-111 in VW cars, or the newer Ford Zetec-SE 16-valve unit and the older Kent engine (Endura-E) in Ford cars.

References