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22R
The 2-valve SOHC 2.4 L (2,366 cc) 22R was produced from 1981 through 1995.
Cylinder bore was 91.9 mm (3.62 in) and stroke was 88.9 mm (3.5 in).

Initial output was 97 hp (72 kW) at 4,800 rpm and 129 lb·ft (174 N·m) at 2,800 rpm.
By 1990 the 22R was producing 108 hp (81 kW) at 5,000 rpm and 138 lb·ft (187 N·m) at 3,400 rpm.

22R-E engine fitted in a 1989 Hilux Surf
The first fuel injected 22R-E engines appeared in August 1982.
Output of these engines is commonly rated at 105 hp (78 kW) at 4,800 rpm and 137 lb·ft (185 N·m) at 2,800 rpm.

In 1985, the engine was significantly reworked, output was up to 112 hp (84 kW) at 4,600 rpm and 142 lb·ft (192 N·m) at 3,400 rpm. Many parts from the newer 22R-E are not compatible with those from the older pre-1985 engine. Non-compatible parts include the cylinder head, block, pistons and many of the associated parts such as the timing chain and cover, and water and oil pumps (although the oil pump internals are the same). These changes also affected the 22R, therefore one can consider the 85-95 22R-E as a fuel injected version of the 85-90 22R with only minor differences, if any.

Toyota swapped the dual row timing chain used in older engines for a single row chain with plastic guides in 1983. This system reduced drag on the engine, but was occasionally problematic. Every 80,000 to 140,000 miles the chain would sometimes stretch to the point that the hydraulic-operated chain tensioner can not take up any more slack. When this happens, the timing chain impacts the driver's side chain guide, breaking the plastic within a few hundred miles of driving and creating a noticeable chattering sound in the front of the engine, especially when cold. If the engine continues to be operated after the guide breaks the chain will stretch rapidly (an unfortunate characteristic of single row chains). The loose chain causes inaccurate ignition timing which usually results in noticeable rough running. In continued operation, the chain can jump a tooth on the drive sprocket or break entirely, with either case resulting in engine damage from valve-piston collisions. Also, the stretched chain will slap against the side of the timing cover due to the broken guide, and can wear through the cover and into the coolant passage behind the water pump. This will cause coolant to drain in to the crankcase / oil pan, possibly causing damage to internal engine components such as the bearings, crankshaft, camshaft as well as damage caused by overheating due to the lack of coolant (since it has drained into the engine oil).

The turbocharged 22R-TE (sold from late 1985 through 1988) produced 135 hp (101 kW) at 4,800 rpm and 173 lb·ft (234 N·m) at 2,800 rpm.

These engines are extremely well known for their durability, decent fuel efficiency and good low to mid range torque.

However, its weakness is high-end power. The 22R has a large displacement and a strong block, but its comparatively long stroke and restrictive head limit its use in high revving applications. Thus, the Toyota 18R-G, 2T-G, 4A-GE and 3S-GE 4-cylinder engines are better suited for performance applications.

A popular modification to the 22R is to use a 20R head. This head has smaller combustion chambers, giving a higher compression ratio, which then allows more power to be developed. The 20R head also flows better than the 22R head, which improves high RPM power. The 20R head is a simple bolt-on modification for the early, pre 1985, block, but also requires the use of the 20R intake manifold, making it impossible to use with the 22RE EFI system.[14] For the later, 1985 onwards, 22R block, further modifications are required.[15]>>>>MORE HERE>>>>>http://en.wikipedia.org/wiki/Toyota_R_engine#22R