disel engine v/s petrol engine

Replies

• 

  zaveri

  diesel engines include fuel pumps and injectors, due to which the number of moving parts may increase in number, and this might contribute to the vibrations.
• 

  mechky

  VISHNUGOPAN

  diesel engines are not as smooth as petrol engines. they vibrate a lot. why?

  I think you are referring to the more noisy operation of diesel engines as compared to the petrol engines. It is due to the nature of diesel combustion process - the sudden ignition of the diesel fuel when injected into the combustion chamber causes a pressure wave. It is because of this pressure wave we have that characteristic noise of diesel engine which is less smooth than the petrol engine.
  However, now a days diesel engines are very efficient and noise is considerably low. There are many methods incorporated to reduce this noise of diesel engine - indirect injection, pre-injection, injection timing, injection rate, compression ratio, EGR, CRDi, higher cetane rating fuel.
• 

  mechky

  zaveri

  diesel engines include fuel pumps and injectors, due to which the number of moving parts may increase in number, and this might contribute to the vibrations.

  These days almost all the Petrol engines have fuel injectors and pumps. It has nothing to do with the vibrations.
• 

  VISHNUGOPAN

  But why a petrol combustion process isn't creating as much noices or vibrations as a diesel engine.
• 

  mechky

  VISHNUGOPAN

  But why a petrol combustion process isn't creating as much noices or vibrations as a diesel engine.

  Pressure wave will be generated when auto-ignition of fuel occurs. Diesel combustion is a auto-ignition process. In Petrol engines we avoid auto-ignition by keeping the compression ratio low. So, pressure rise in petrol engines during combustion is relatively low as compared to diesel engines.
• 

  nibhani

  vibration is produced due to knocking .diesel is more energetic fuel than petrol and in diesel engine there is higher pressure ratio than petrol engine that is the reason that it vibrates a lot than petrol engine...and as i know that diesel engine produces more uniform torque than petrol so its running tendency is more smooth than petrol engine...
• 

  vikaskumar11233

  Then why diesel engine is not powerful in comparison to the petrol engine.
• 

  piyusheddie

  hey guys,
  
  In ma opinion regardless of Petrol's high price, Petrol engines r always better then Diesel engines in all aspects. There are variety of advantages of Petrol engine so its better. The Petrol engine is less in NHV (Noise Harshness & Vibrations), smooth, high performance, less moving parts as compare to Diesel engines, light weight, moreover the main advantage is dat Petrol engines r less in pollution emission as compare to Diesel engines.
  The only drawback of Petrol engine is dat it cant compete with the Diesel engine in terms of high torque produced in diesel engine, which is very helpful in commercial purposes. And somewhat low diesel prices in India.
• 

  vikaskumar11233

  Thanks Piyusheddie.
• 

  nibhani

  mec

  vikaskumar11233

  Then why diesel engine is not powerful in comparison to the petrol engine.

  vikaskumar11233

  Then why diesel engine is not powerful in comparison to the petrol engine.

  thermal efficiency of diesel engine is greater than petrol engine....diesel is a more powerful fuel than petrol...the compression ratio is higher of diesel engine that is the reason that more heat of fuel is converted in to energy to run diesel engine....that is the reason that thermal efficieny is greater than petrol engine...