Contents: Petrol engines ↡ Diesel engines ↡
In order to obtain a compact car, Mercedes designers had to take a new path when developing the power plant for A-class cars. The extremely inclined position of the engine required a new design.
The result was a completely new generation of 4-cylinder engines with a light metal alloy cylinder head, including 4 M-166 series petrol engines and 4 OM-668 series turbodiesel engines.
The powertrain is positioned at an angle in the car, just behind the bottom of the footwell, under the pedals.
The surface of the power unit facing the passenger compartment is designed in such a way that in the event of a frontal impact, the power unit goes under the bottom (see illustration 1.0).
Petrol engines
The camshaft, located on five bearings in the cylinder head made of a light metal alloy, acts on both cylinder valves through the rocker arm.
The camshaft is driven from the crankshaft by a maintenance-free chain.
Diesel engines
Diesel engines have four valves per cylinder. The valves are driven by two camshafts connected by sprockets.
The intake camshaft is driven by a double-row roller chain from the crankshaft (see illustration 1.0a).
1.0 Front axle and power unit of a car with a gasoline engine
1 - gear selection rod
2 - gear shift lever
3 - shock absorber strut
4 - brake disc
5 - support
6 - left axle shaft
7 - manual gearbox
8 - anti-roll bar
9 - ignition coil block
10 - transverse suspension arm
11 - engine
1.0a Distributive Fuel Injection (CDI) Diesel engine
1 - exhaust pipe
2 - gearbox
3 - oil level sensor
4 - guide tube of the oil level indicator pin (dipstick)
5 - starter
6 - oil filter
7 - oil filter cover
8 - fuel filter
9 - intake manifold
10 - oil separator
11 - crankcase ventilation hose
12 - vacuum pump
13 - cylinder head
14 - chain tensioner
15 - Right engine support bracket
16 - cylinder block
17 - water pump of the cooling system
18 - auxiliary drive belt pulley on the crankshaft
19 - Engine support bracket on the oil pan
20 - V-belt tension roller
21 - generator
22 - air conditioning compressor
23 - drain plug
24 - rear engine mount
Article was obtained from the portal (MERCEDESMAN.ru)