What is CI engine and SI engine?

What is CI engine and SI engine?

in S.I engines,ignition process is carried out with the help of a spark plug which ignites a mixture of air and fuel that is compressed in the combustion chamber. Whereas,a diesel engine also known as Compression Ignition (C.I) engine works on the basis of Diesel cycle or Constant pressure heat addition cycle.

Which is faster petrol or diesel?

Petrol is well refined than a diesel , The flame speed of petrol is much faster than diesel. Since flame speed is high all of its energy is released in sudden. Hence lesser reciprocating weight and faster combustion gives petrol engine its better acceleration , also its torque curve is almost linear.

Why diesel engines are called CI engines?

The diesel engine (also known as a compression-ignition or CI engine), named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to the mechanical compression (adiabatic compression).

Why diesel engine has more torque?

There are several reasons as to why a diesel engine produces more torque than a gasoline (petrol) engine. … The compression ratio of normal diesel engines is higher than that of its gasoline counterparts. It adds to the development of higher peak pressure inside the combustion chamber and, hence, on the crankshaft.

Which car is good petrol or diesel?

The mileage of the diesel engine is more than that of a Petrol engine. A diesel engine does not need a spark plug and thus has higher compression. This makes the diesel engine utilise more fuel as compared to a petrol engine.

Which engine is more powerful?

Petrol engine will have higher power than diesel engine because it can run at much higher RPM and as power is directly proportional to the RPM hence, petrol engine will produce more power, although diesel engine has more Torque, but it will not produce same amount of power as petrol engine, as it has low RPM.

What is diesel made of?

Diesel fuel is a mixture of hydrocarbons—with boiling points in the range of 150 to 380°C—which are obtained from petroleum. Petroleum crude oils are composed of hydrocarbons of three major classes: (1) paraffinic, (2) naphthenic (or cycloparaffinic), and (3) aromatic hydrocarbons.

What does torque mean?

Torque is the amount of "turning power" you have, much in the same way you turn a wrench. 369 foot-pounds means that if you had a wrench that was 1 foot long, and applied a force of 369 pounds directly perpendicular to that wrench, you would get 369 foot-pounds of torque.

Why Diesel is used in heavy vehicles?

Bulky automobiles such as trucks and cars require a huge amount of force to run the vehicle at the slow speed. As almost everybody knows that petrol burns faster than diesel, the diesel engine achieves a higher torque at slow speed. … So that's why are diesel engines used in heavy vehicles.

How many types of engines are there?

Types of Engine. Basically the engines are of two types, and these are external combustion engines and internal combustion engines.

What is petrol made of?

Gasoline is made from crude oil. The crude oil pumped out of the ground is a black liquid called petroleum. This liquid contains hydrocarbons, and the carbon atoms in crude oil link together in chains of different lengths.

Is it bad for diesels to idle?

In any case, letting your diesel idle for anything more than a short duration is a bad idea because while the engine will use little fuel, what fuel it does burn will not combust completely because the operating temperature is too low. … The best rule is, if you're not underway, turn off the engines.

Which has higher calorific value petrol or diesel?

The calorific value of diesel fuel is roughly 45.5 MJ/kg (megajoules per kilogram), slightly lower than petrol which is 45.8 MJ/kg. However, diesel fuel is denser than petrol and contains about 15% more energy by volume (roughly 36.9 MJ/litre compared to 33.7 MJ/litre).

What does compression ratio mean?

Definition of compression ratio. : the ratio of the maximum to the minimum volume of the space enclosed by the piston of an internal-combustion engine during a full stroke. — called also compression.

Do diesels last longer than petrol?

Diesel engines do last longer than petrol ones. Diesel is a light oil and when burned and used as fuel by the vehicle it lubricates the parts of the engine. This prolongs the life of the engine. … While diesel engines typically last longer they are more costly to repair.

Why are diesel cars not popular in the US?

The reason diesel cars are, arguably, better vehicles than gasoline is because diesel fuel is — and this is less debatable — a better fuel than gasoline. … Gasoline emissions per gallon are, “About 19.6 pounds of CO2 are produced from burning a gallon of gasoline.

Which engine has more power 2 stroke or 4 stroke?

Typically, a 2-stroke engine creates more torque at a higher RPM, while a 4-stroke engine creates a higher torque at a lower RPM. … That being said, 2-stroke engines are more powerful. Two-stroke engines are a much simpler design, making them easier to fix. They do not have valves, but rather ports.

Why is diesel cheaper than petrol?

Diesel fuel is heavier and less volatile than gasoline, which makes it simpler to refine from crude oil. As a result, diesel tends to be cheaper than gasoline in most countries around the world. … For example in the USA the federal excise tax on gasoline is 18.4 cents per gallon and 24.4 cents per gallon for diesel fuel.

What is the efficiency of diesel engine?

A typical diesel automotive engine operates at around 30% to 35% of thermal efficiency. About 65-70% is rejected as waste heat without being converted into useful work, i.e. work delivered to wheels. In general, engines using the Diesel cycle are usually more efficient, than engines using the Otto cycle.

How does diesel engine start?

Diesel engines are sometimes called compression-ignition engines because initiation of combustion relies on air heated by compression rather than on an electric spark. In a diesel engine, fuel is introduced as the piston approaches the top dead centre of its stroke.

What is the use of fuel injector?

The function of a fuel injector is to spray atomized fuel into the combustion chamber of an internal combustion engine. Fuel injection became the primary fuel delivery system in automobiles starting in the mid-1980s. The spray from a fuel injector can be continuous or intermittent.

Is diesel cleaner than gas?

But the fact remains that diesels are more efficient than gasoline engines—and according to one recent study, newer models are cleaner, except for their higher emissions of nitrogen oxides. … Because diesels are more efficient, they do in fact emit less carbon dioxide than gasoline engines.

What is compression ratio of diesel engine?

Diesel engines have no spark plug. … Compression is much higher with a diesel engine (14:1 to 25:1) than a gasoline engine (8:1 to 12:1). Gasoline engines use lower compression ratios to avoid fuel auto ignition (engine knock). Higher compression ratios lead to higher thermal efficiencies and better fuel economies.