The cylinder bores are bored in a gray cast iron crankcase. If the cylinder walls are heavily worn or have scratches on them, they can be honed at a service station. After honing, larger diameter pistons should be installed in the cylinders. The lower part of the crankcase contains a crankshaft mounted in bearings. The connecting rods connecting the pistons to the crankshaft are mounted on the crankshaft with plain bearings. The lower part of the engine is closed by an oil pan, which contains the engine oil necessary for lubrication and cooling. The cylinder head is bolted to the crankcase from above. Depending on the engine, the cylinder head is made of gray cast iron or a light (aluminum) alloy.
The cylinder heads of gasoline engines are made according to the so-called principle of organizing the transverse movement of the charge. This means that fresh fuel-air mixture is supplied to the cylinder head from one side, and the exhaust gases are removed from it from the other side. Due to the transverse movement of the gas flow through the intake and exhaust valves, a rapid change of charge in the cylinders is carried out.
The 4-cylinder OHC (Over Head Camshaft) engine has an overhead camshaft (located in the cylinder head). The camshaft is driven from the crankshaft by a toothed belt. The camshaft drives the valves through pressure levers.
The 4-cylinder DOHC (Double Over Head Camshaft) engine has 2 camshafts in the cylinder head. One camshaft controls the intake valves, and the other - the exhaust valves. Driven from the crankshaft by a common chain, the camshafts act on the valves through hydraulic tappets.
The V6 engine has a single central camshaft that drives the intake and exhaust valves via pushrods and rocker arms. The camshaft is driven by a chain, and in the 2.8L engine, by gears.
The 6-cylinder V-shaped engine with a working volume of 2.9 liters has 4 camshafts. In each cylinder bank, one camshaft controls the intake valves, and the other - the exhaust valves. The camshafts are driven by a chain.
In diesel engines, the camshaft is located on the side of the cylinder block. It drives the intake and exhaust valves via tappets and rocker arms. The camshaft is driven by a chain. Due to lack of space, the intake and exhaust manifolds are located on the same side of the cylinder head.
The engine is lubricated by an oil pump, which is located in the oil pan and is driven from the camshaft via an auxiliary shaft. The oil taken from the oil pan is supplied through holes and channels to the bearings of the crankshaft and camshaft, as well as to the working surfaces of the cylinders.
The coolant pump is located at the front of the crankcase and is driven by a V-belt or poly-V-belt, which also drives the generator. Some models have a cooling system fan on the coolant pump shaft, which is switched on via a viscous coupling at a certain coolant temperature. It is necessary to ensure that the cooling system is filled with a mixture of soft water, antifreeze and anti-corrosion additives all year round.
To prepare and ignite the fuel-air mixture, gasoline engines are equipped with a carburetor or a maintenance-free electronically controlled fuel injection system.
The ignition spark in a gasoline engine is produced by a maintenance-free electronic ignition system.
Safety note: Switch off the ignition before working in the engine compartment. The cooling fan may switch on automatically. which is caused by the heat build-up in the engine compartment. Risk of injury from V-belt and fan blades!
(The text of the article was copied from the website: FORDBOOK)