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| Manufacturer | Toyota |
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The A Series engines are a family of straight-4 internal combustion engines with displacement from 1.3 L to 1.8 L produced by Toyota Motor Corporation. The series has cast iron engine blocks and aluminum cylinder heads.
The development of the series began in the late 1970s, when Toyota wanted to develop a completely new engine for the Toyota Tercel, successor of Toyota's K engine.[1] The goal was to achieve good fuel efficiency and performance with a modern design.[2][3] First result was 1.5 L 1A for AL10 Tercel. These first A engines are non-crossflow engines, where the inlet and exhaust manifolds are on the same side of the cylinder head cover. Later on, the series expanded on more A engines, and Toyota began using them on other Toyota models, while the Third generation Tercel moved on to use E series engines.
Toyota joint venture partner Tianjin FAW Xiali still produces the 1.3 L 8A and recently restarted production of the 5A. In between, many interesting variations were produced, including one of the first mass-production 5-valve engines (the 20V 4A-GE) and the 170 hp (127 kW) supercharged 4A-GZE.
4A-GE (16-valve)
The next major modification was the high-performance 4A-G, with the fuel injected version, the 4A-GE, being the most powerful. The 4A-GE was one of the earliest inline-4 engines to have both a DOHC 16 valve configuration (four valves per cylinder, two intake, two exhaust) and electronic fuel injection (EFI). The cylinder head was developed by Yamaha Motor Corporation. The reliability and performance of these engines has earned them a fair number of enthusiasts and a fan base as they are a popular choice for an engine swap into other Toyota cars such as the KE70 and KP61. New performance parts are still available for sale even today because of its strong fan base. Production of the various models of this version lasted for five generations, from 1983 through 1991 for 16-valve versions and the5-valve 4A-GE lasted through 1998.
The first-generation 4A-GE which was introduced in 1983 replaced the 2T-G in most applications. This engine was identifiable via silver cam covers with the lettering on the upper cover painted black and blue, as well as the presence of three reinforcement ribs on the back side of the block. It was extremely light and strong for a production engine using an all-iron block, and produced 112 hp (84 kW) at 6600 rpm and 131 N·m (97 lb·ft) of torque at 4800 rpm in the American market. The use of a vane-type air flow meter (MAF), which restricted air flow slightly but produced cleaner emissions that conformed to the U.S. regulations, limited the power to 112 hp (84 kW); the Japanese model — which used a manifold absolute pressure (MAP) sensor — was originally rated at 130 PS (96 kW), however this was a gross power rating and the motor was later re-rated at 120 PS (88 kW) net.[6] Japanese cars tested no faster than their American counterparts, despite a higher power rating and a lighter curb weight,[7]
Toyota designed the engine for performance; the valve angle was a relatively wide 50 degrees, which at the time was believed to be ideal for high power production. Today, it should be noted that more modern high-revving engines have decreased the valve angle to 20 to 25 degrees, which is now believed to be ideal for high-revving engines with high power per litre. The first generation 4A-GE is nicknamed the "bigport" engine because it had intake ports of a very large cross-sectional area. While the port cross-section was suitable for a very highly modified engine at very high RPM, it caused a considerable drop in low-RPM torque due to the decreased air speeds at those RPM. To compensate for the reduced air speed, the first-generation engines included the T-VIS feature, in which dual intake runners are fitted with butterfly valves that opened at approximately 4200 rpm. The effect was that at lower RPM when the airspeed would normally be slow, four of the eight runners were closed, this forced the engine to draw in all its air through half the runners in the manifold. This raised the airspeed which caused better cylinder filling and also better fuel atomisation. This enabled the torque curve to still be intact at lower engine speeds, allowing for better performance across the entire speed band and a broad, flat torque curve around the crossover point. During rising engine speed, a slight lurch can occur at the crossover point and an experienced driver will be able to detect the shift in performance. Production of the first-generation engine model lasted through 1987.
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