The Hillman Avenger, produced from 1970 to 1981, utilized a range of four-cylinder, all-iron overhead valve (OHV) engines, with displacements evolving over its production run to offer varying levels of performance and meet market demands. Initially, the car was launched with 1250 cc and 1500 cc engine options, which were later upgraded to 1300 cc and 1600 cc. Specific high-performance variants, such as the Avenger Tiger, featured modified versions of these engines with enhanced power output. International markets also saw unique engine configurations, including an 1800 cc unit for South America and a Peugeot engine for South African models.

According to www.iAsk.Ai - Ask AI: The Hillman Avenger (1970-1981) was primarily equipped with four-cylinder, all-iron overhead valve (OHV) engines. The engine specifications varied by model year and market, but the core displacements were 1250 cc, 1500 cc, 1300 cc, and 1600 cc.

Engine Specifications by Displacement and Variant

1250 cc (1.25 L) and 1500 cc (1.5 L) Engines (1970-1973) At its introduction in February 1970, the Hillman Avenger was available with two engine options: a 1250 cc and a 1500 cc four-cylinder OHV unit [1] [2] [3] [4]. These engines were purpose-designed for the Avenger and were distinct from those used in the larger "Arrow" series Hunter [2]. The 1250 cc engine was typically paired with DL and Super trim levels, while the 1500 cc engine was available across DL, Super, and GL trims [2]. The 1256 cc engine, for instance, produced approximately 53 horsepower, allowing for a top speed of around 85 mph (137 km/h) and 0-60 mph acceleration in about 18 seconds [5]. Fuel economy for this engine was approximately 30-35 mpg [5].

For the North American market, the Plymouth Cricket, a rebadged Avenger, exclusively used the 1500 cc engine, as the 1250 cc was deemed underpowered for American preferences [2] [11]. This engine's compression was lowered from 9.2 to 8.0:1, and it was rated at 70 gross horsepower [12].

1300 cc (1.3 L) and 1600 cc (1.6 L) Engines (1973-1981) In October 1973, both engine sizes were upgraded. The 1250 cc became the 1300 cc, and the 1500 cc became the 1600 cc [1] [2] [4]. These upgrades also included revisions to the cylinder head design to improve fuel economy [13]. The 1300 cc engine was offered with both single and twin carburettor setups, while the 1600 cc engine was available with twin carburettors for higher trim levels [6]. The 1600 cc engine in the GLS trim, for example, was a high-compression unit [1].

Avenger Tiger Engine (1972-1973) A notable high-performance variant was the Hillman Avenger Tiger, launched in March 1972 [1] [2] [4]. This model featured a modified 1500 cc GT engine with an improved cylinder head, enlarged valves, and twin Weber (or Dell'Orto) carburettors [1] [2] [6]. The compression ratio was increased to 9.4:1, resulting in a power output of 92.5 bhp (69 kW) at 6,100 rpm [1] [2]. This allowed the Tiger to achieve 0-60 mph in 8.9 seconds and a top speed of 108 mph (174 km/h) [1] [2].

International Engine Variations

• South America (Brazil and Argentina): The Avenger was built in Brazil from 1973 to 1981, initially as the Dodge 1800, named for its 1.8 L engine [1] [14]. This 1.8 L unit was a larger version of the standard Avenger power unit and was not sold in Europe [14]. In Argentina, the Dodge 1500 (later Volkswagen 1500) also offered a 1.8 L engine option [1] [14].
• South Africa: To comply with local content regulations, the South African-assembled Dodge Avenger utilized a locally manufactured 1.6 L Peugeot engine, shared with the Peugeot 404 [1] [15].
• Iran: The Avenger built in Iran (1978-1980) used the Hillman Hunter engine, also found in the locally manufactured Paykan [1].

Engine Design and Characteristics

The Avenger's engines, despite being OHV, were designed with the camshaft positioned higher than typical OHV engines, resulting in shorter pushrods, making them closer to an overhead camshaft design [9] [13]. This design contributed to their strength, quiet operation, and ability to rev up to 7000 rpm [9] [13]. They were known for providing good performance and economy, and while they could become noisy with high mileage, they rarely failed [9]. The inherent toughness of these engines was further demonstrated by their use in the Hunter Arrow series (Paykan) in Iran from the mid-1980s [9] [13].

The engines were generally robust when properly maintained, though issues like head gasket failure were not unheard of, and twin-carburettor models could experience choke cable failures [5] [7].

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