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Brief description

Brief description

The diesel engine is transversely mounted, fluid cooled, 4 cylinder in-line engine with 4 valves per cylinder, 1 overhead camshaft and 2 balancer shafts. The balancer shafts are located in a bearing member under the crankshaft. The engine has direct injection, meaning that fuel is injected into the combustion chamber and turbocharger in order to achieve high torque within the normal speed range. This is a cross-flow engine type, i.e. it contains inlet ports on one side of the combustion chamber and exhaust ports on the other.

Its total swept volume is 2.2 litres and provides, together with the turbocharger, a high engine torque even at low speeds for comfortable driving in normal urban traffic.

The balancer shafts are used to absorb any vibration and other forces coming from the moving parts of the engine and reduce unwanted engine noise.

Diesel engine working principle

A diesel engine works with four strokes, induction, compression, power and exhaust, but does not have spark plugs to initiate the combustion of the air/fuel mixture. Instead, the engine is designed with high compression and specially-formed combustion chambers.

The principle is that pure air is drawn into the cylinders and is compressed there. In the compression stroke, the air will become so hot that the fuel being injected will self-ignite and expand rapidly, causing the power stroke. The next stroke is a normal exhaust stroke.

The engine works by mixing air and fuel only when the fuel is injected into the compressed air. There is no throttle body and the air can flow freely the whole time. Engine speed is instead controlled with a high-pressure pump which allows the correct amount of fuel is injected to each cylinder with the correct timing. The pump is controlled by the engine control module which receives information regarding accelerator pedal position and performs a calculation. When the calculation has been made, the control module sends a request to the pump control module regarding a certain volume of fuel which determines engine torque.

A diesel engine is normally 30% more efficient than a petrol engine. This means that fuel consumption is lower than corresponding petrol engines.

A diesel engine's mechanical construction is similar to petrol engine construction with a crankshaft, connecting rods, pistons, camshaft and valves but does not contain an ignition system or throttle body. Since the engine has no throttle body, no hoses for vacuum servo, etc. are required and means that the engine contains a separate vacuum pump.