See Figures 1 through 5
A 135 cid (2.2L) engine is standard. A 156 cid (2.6L) engine, manufactured by Mitsubishi, is optional on 1982-86 models. A 153 cid (2.5L) Chrysler built engine is optional on 1987-95 models. It is based on the 2.2L engine, achieving its increased size through a longer stroke (4.09 in. vs. 3.62 in.). The Premier models came equipped with only one 4-cylinder engine, which is also a 2.5L engine. Throughout this information it will be referred to as the 2.5L Premier engine. Also optional on some recent models is a turbocharged version of the 2.2L engine, employing dished pistons, which lower the compression ratio to 8.5:1.
The 2.2L engine is a four cylinder overhead camshaft power plant with an aluminum cylinder head. The crankshaft is supported by five main bearings. No vibration damper is used. A sintered iron timing belt sprocket is mounted on the crankshaft. The intake manifold and oil filter base are aluminum. The 2.2L engine came in five different options: carbureted version, EFI version, Turbo I version (1984-88), Turbo II version (1987-88-the only difference between the Turbo I and Turbo II 2.2L engines was that the Turbo II was equipped with an intercooler), and the Turbo III version (1989-93-this engine was equipped with a 16 valve cylinder head, unlike the other 2.2L turbocharged engines).
The 2.6L engine is also a four cylinder overhead camshaft power plant with a cast iron block, aluminum head and a silent shaft system. The countershafts (silent shafts) are incorporated in the cylinder block to reduce noise and vibration. Its most distinguishing feature is a jet valve located beside the intake valve of each cylinder. This valve works off the intake valve rocker arm and injects a swirl of air into the combustion chamber to promote more complete combustion. The 2.6L engine was only equipped with a carburetor.
The 2.5L Chrysler engine is essentially the same as the 2.2L engine, although a different block casting was used to accommodate the longer stroke. Even though many basic components and dimensions are shared, the 2.5L, and 2.2L Turbo III, engines incorporates one very radical change: a balance shaft system to minimize vibration. These two, counter-rotating shafts are located in a special housing mounted to the underside of the block and under the crankshaft, within the oil pan. The shafts are interconnected by gears and driven (from the crankshaft) through a roller chain to keep them in time. The 2.5L engine was equipped with one of three types of induction systems: Electronic Fuel Injection (EFI) from 1986-95, turbocharged Multi-point Fuel Injection (MFI) from 1989-1992 (termed the 2.5L Turbo I-not to be confused with the 1984-88 2.2L Turbo I engine) and the Flexible Fuel EFI induction system from 1993-95. The Flexible Fuel system is designed to operate on a mixture of up to 85 percent methanol and 15 percent unleaded gasoline. These vehicles also operate on mixtures containing a lower percentage of methanol, or just pure unleaded gasoline. Engine components which are required for safe operation using fuel containing methanol alcohol are identified by a standard green color and/or display the statement "Methanol Compatible'' imprinted on the component.
The 2.5L Premier engine, which is available only in the 1988-89 Premier, is not the same engine as the Chrysler built 2.5L engine. The 2.5L (150 cid) Premier four-cylinder engine is an in-line, lightweight, overhead valve engine. This engine is designed for use with unleaded fuel only. The cylinder head has dual quench-type combustion chambers, which creates turbulence and fast burning of the air/fuel mixture; this results in good fuel economy. The cylinders are numbered 1 through 4 from the front to the rear of the engine. The crankshaft rotation is clockwise, when viewed from the front of the engine. The crankshaft rotates within five (5) main bearings and the camshaft rotates with four (4) line-bored bearings.