Are you planning to buy a car Or already have one? Then, this is for you, as we know a car has many sections like chassis, body, engine, transmission. An engine is the heart of a car. Power and torque are the major outcomes of an engine, but do you ever think of what does power and torque actually mean? What does that brochure tell you about your car and its engine? Well! We bet you if you go out to buy a car next time after reading this, you would know all these answers when it comes to car engine. Let’s have a look.
There are several types of engines e.g. Heat engines (Combustion engine & Non-Combusting Heat engines), Non thermal chemical powered engine, Electric Engine etc. But here we are talking about commercial car engines, Internal combustion engines, whereas, electric engines and hybrid engines are also becoming popular now a days.
Internal Combustion engines (Petrol or Diesel) have combustion of a fuel occurs in a combustion chamber with an oxidizer.
Four stroke engines have 4 stages which we call strokes. They are
Induction (Fuel Intake)
Ignition (Fuel is burnt)
Emission (Exhaust out)
ENGINE CONTROL SYSTEM
A control system deals with electric system or subsystems in a motor vehicle. Now a days, manufacturers use electronic control systems. Basically, it is an embedded system which controls other electric systems. These are referred as car’s computer e.g.
Brake control module
Suspension control module
Body control module
Engine control module
Power tells how fast a work can be done. When you pull a cart up to some distance, you deliver work. How fast you can do that determines your power (in combination with the distance and the weight you pull). It is expressed in kilowatts and HP (Horse Power).
It can be determined by Torque * Rotations divided by per unit time.
Torque is a force that tends to rotate or turn things. Torque is a measurement of twisting force. Tightening the lug nut of your car wheels is a good example. It is measured in Newton-Meter.
For a 4 stroke engine, Torque is generated in 3rd stroke i.e. Ignition.
Compression ratio is a value that represents the ratio of the volume of combustion chamber from its largest to smallest capacity. It is a ratio when piston is at the bottom of the stroke and the top of the stroke.
BORE & STROKE
Bore is the diameter of the circular chamber cut into the cylinder block. Typically, we refer stroke as a piston and they both decide the displacement of the Engine. Shorter stroke and wider bore increases revolution, hence increases the power as per the equation (Horsepower = Torque x rpm divided by 5252).
DISPLACEMENT, CAPACITY & CC
Engine displacement is determined by multiplying the piston stroke by the square of the cylinder bore times 0.7854.
=stroke x bore x bore x 0.7854
Capacity of an engine is simply the amount of water to fill all the cylinders when you put all the pistons at the bottom of the engine.
CC cubic centimeter is a measure of the combustion space in the cylinders.
There are different styles in which cylinders of an engine are arranged such as Inline, V shaped W shaped, Radial, Opposed pistons. E.g. 2.7L Eco Boost® V6
V-Shaped engine means cylinders are arranged in V shaped inside the engine, used by Mercedes, Lamborghini.
FUEL DELIVERY & FUEL EFFICIENCY
Fuel can be delivered by carburetor and Fuel injection system. Fuel injection system increases fuel efficiency and trending now a days which makes use of a dedicated system or microcontroller to inject the fuel into engine.
Fuel efficiency means the efficiency of a process to convert chemical energy in a fuel to useful kinetic energy.
It depends upon several facts such as type of combustion used, Power, coolant, the way you drive.
Fuel economy is the distance travelled per unit volume. (e.g.15km/ltr)
Well! Honestly, the topics we have discussed above are just in brief. You might be thinking of the outcome?
So, an honest answer is now you can at least put a counter question to sales man or can understand what he says. He can’t make you fool by trapping in technicalities.
Isn’t it? 🙂
Stay tuned! Stay blessed… 🙂