Engines 4A-FE and 7A-FEin-line 4-cylinder, 16-valve overhead camshafts. The working volume of the 4F-FE engine is 1.6 liters, and the 7A-FE engine is 1.8 liters. The cylinders are numbered from the crankshaft pulley.
The order of operation of the cylinders: 1-3-4-2. The design and layout of these engines have much in common, so their description is carried out in parallel with an indication of the design features of each type of engine
The 4A-FE engines are available in three variants, which differ from each other mainly in the design of the intake and exhaust systems:
- Serial version with catalytic converter of exhaust gases
- Engine variant with variable intake manifold geometry system (Lean burn). This engine variant can also have an intake system with additional throttling before the intake valves;
Engine 7A-FE has a number of design differences, which will be discussed as we proceed.
Crankshaft - full support with 5 main bearings. Bearing shells are made on the basis of aluminum alloy and are installed in the bores of the engine crankcase and main bearing caps.
Cylinder head, cast from aluminum alloy, has transverse and oppositely located intake and exhaust pipes, assembled with tent-shaped combustion chambers. Spark plugs are located in the center of the combustion chambers.
Camshaft the exhaust valves are driven from the crankshaft by a toothed belt, and the intake camshaft is driven from the exhaust camshaft by a gear transmission. Valve clearance is adjusted using adjusting washers located between the cams and valve tappets.
Pistons made of high temperature aluminum alloy.
Piston pins - "fixed" type. They are installed with tension in the piston head of the connecting rod, but have a sliding fit in the piston bosses.
Compression rings: the upper compression ring is made of stainless steel, the lower compression ring is made of cast iron.
Oil scraper ring consists of two scrapers and an expander. The oil scraper ring removes excess oil from the cylinder walls, preventing it from entering the combustion chamber.
Cylinder blockcast from cast iron.