4A-FE and 7A-FE enginesin-line 4-cylinder, 16-valve with overhead camshafts. The displacement of the 4F-FE engine is 1.6 liters, and the 7A-FE engine is 1.8 liters. Cylinder numbering is from the crankshaft pulley.
The order of operation of the cylinders: 1-3-4-2. There is much in common in the design and layout of these engines, so their description is carried out in parallel with an indication of the design features of each type of engine
4A-FE engines are available in three versions, which differ from each other mainly in the design of the intake and exhaust systems:
- Standard version with catalytic converter
- Engine variant with intake manifold geometry change system (Lean burn). This engine variant may also have an intake system with additional throttling upstream of the intake valves;
Engine 7A-FE has a number of design differences, which will be discussed in the course of the presentation.
Crankshaft - full support with 5 main bearings. The bearing shells are made on the basis of an aluminum alloy and are installed in the bores of the engine crankcase and main bearing caps.
cylinder head, cast from an aluminum alloy, has transverse and located on opposite sides inlet and outlet pipes, arranged with tented combustion chambers. The 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 train. The clearance in the valves is adjusted using shims located between the cams and valve lifters.
Pistons Made from high temperature aluminum alloy.
piston pins - "fixed" type. They are installed with an interference fit 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 iron.