The internal combustion engines are the engines in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine the expansion of the high temperature and high pressure gases produced by combustion apply direct force to some component of the engine. The force is applied typically to pistons, turbine blades or a nozzle.
Principle of operation:
As the combustion takes place internally inside the cylinder (a part of working fluid circuit) the engine is called internal combustion engine.

Classification of Internal Combustion Engines:
Today’s IC engines can be classified in several ways. Some of the ways of classification of Internal Combustion (IC) engines is listed below:
- Automobile Engine
- Aircraft Engine
- Locomotive Engine
- Marine Engine
- Stationary Engine
- Reciprocating: Single cylinder, Multi-cylinder In-line, V, radial, opposed cylinder, Opposed Piston.
- Rotatory: Single motor, Multi motor
- Atkinson (For complete expansion SI Engine)
- Diesel (For the Ideal Diesel Engine)
- Dual (For the Actual Diesel Engine)
- Miller (For Early/Late Inlet valve closing type SI Engine)
- Otto (For the Convectional SI Engine)
- Four stroke cycle
- Two stroke cycle
- Scavenging ; direct/crankcase/cross flow; back flow/loop; Uni flow
- Naturally aspirated or turbocharged
- Design of valve/port
- Poppet valve
- Rotatory valve
- Location of valve/port
- T-head
- L-head
- F-head
- L-head
- Convectional
- Crude oil derivatives; Petrol, diesel
- Other sources; coal, bio-mass, tar stands, shale
- Alternative
- Petroleum derived: CNG, LPG
- Bio-mass derived: alcohols, vegetable oils, producer gas, biogas and hydrogen
- Blending
- Bi-fuel and dual fuel
- Carburetion
- Fuel injection
- Spark ignition
- Compression Ignition
- Homogeneous Charge
- Stratified charge
- With carburetion
- With fuel injection
- Open chamber: Disc, wedge, hemispherical, bowl-in-piston, bath tub.
- Divided chamber:
- (For CI) 1. Swirl chamber, 2. Pre-chamber
- (for SI) 1. CVCC, 2. Other designs
All Comments
thanks for your post 🙂
Sir , given the max power of an engine at an rpm ….and max torque at an rpm…and i have an engine that is of a bike and needed to be fit to a car ..can we figure out the torque-rpm or rpm-power diagram of my engine, out of this given data?
Sir,
I have a doubt regarding SI engine and CI engine, If we look into the SI engine it is more efficient on 60km/hr something at high speed but case of CI engine it will be at low speed why its happening……??
Thanks so much for your time in writing this blog post.