For 4afe engine
Keywords: for 4afe engine
Description: Toyota 4A-F and 7A-FE engines
The 4A engine series was a 1587 cc (1.6 liter) engine, introduced in 1988, and revised to 4A-FE in 1993. Its primary use was in the Corolla. The 7A engine series was essentially the same engine, stroked for higher displacement (1.8 liters) and better torque. 1997 was the engine's last year: in 1998, it was replaced by the ZZ series. The torque curve was fairly flat, with a steep, linear horsepower curve.
The 4A-FE, by 1993, was producing 105 hp @ 5,800 rpm (75 kW) and 100 lb-ft of torque at 4,800 rpm (136 Nm). In California trim, it produced 100 hp (86 kW). It was a compact DOHC engine for good economy and good driving characteristics. The 7A-FE boasted an extra 10 horsepower and 15 lb-ft of torque, engaging at a lower rpm (110 hp in California); in metric terms, it pushed out 82 kW and 156 Nm.
In 1993, the 4A-FE was given better intake efficiency through use of upright, small-diameter intake ports in the cylinder head, increased valve lift and intake valve diameter; a rotary solenoid type idle air control valve; and a large aluminum stiffener and vanadium-steel crankshaft to reduce noise and vibration.
When the 7A-FE was designed, it was given the same improvements as the 4A-FE, as well as a knock sensor.
At the same time, one of the five original engine mounts in the Corolla was dropped, leaving four; but the right-side engine mount were revised, to a cylindrical, shaft-type liquid-filled compound type to reduce vibration and noise.
Unique to the 7A-FE were two-layer metal head gaskets, and a two-piece oil pan (one piece of aluminum alloy, the other of steel; the upper pan was secured to the cylinder block and transaxle housing). The crankshaft and connecting rod specifications were modified to match the longer piston stroke and higher power output of the 7A-FE engine, and the pistons were made more rigid by modifying the oil return from the slits to 8 holes.