The morse test in I.C engines

Replies

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  engg.ashish

  nothing its comes out with exhaust gases as the fuel that comes in engine is not in liquid form it is in vapor form so it can leave engine without burning but
  here new question arises in diesel engine there is no spark plug it burns by compression thn the fuel is burnt by compression and the temp. of engine like wise in ic engine, fuel in that cylinder can be semi burnt by some compression and temperature or somewhat
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  zaveri

  #-Link-Snipped-#
  
  I am not so sure about it, but i think the morse test is only for petrol engines (spark-ignition engines).
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  engg.ashish

  #-Link-Snipped-# Em talking about petrol engines but giving examples of diesel engine to demonstrate the compression ratio which will be generated in petrol engine for partly burning of petrol air mixture in morse test
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  LIRIL

  In Diesel engine the fuel supply in particular cylinder is cut off. Whereas in Petrol engine the spark plug in shut off.
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  zaveri

  LIRIL

  In Diesel engine the fuel supply in particular cylinder is cut off. Whereas in Petrol engine the spark plug in shut off.

  As if i din't know that.
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  Shashank Moghe

  #-Link-Snipped-# is spot on correct there. If there is no spark in a SI engine, the fuel that comes in goes out of the exhaust, unburned. Similarly, in CI engines, we must cut off the fuel injector signal to inject fuel so that there is no combustion and the power from that individual cylinder can be determined.
  
  In (SI + DI) engines, we have the option of cutting the fuel injector AND the spark signal, and this might be more logical an option since it will save fuel.
  
  P.S: The Morse test is for both petrol and diesel engines.
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  Saddam Nalband

  As spark is responsible of burning the fuel in the cylinder, when there is no production of spark in the cylinder the fuel remains as it is.
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  n1kh1l

  I dont know about morse test but in marine engines we take peak pressure and indicator diagram of individual cylinders to calculate power.
  When fuel is cutoff to a particular cylinder than we get compression pressure instead of peak pressure.
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  kiran ramesh

  Why should we maintain constant friction power in morse test?
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  Shashank Moghe

  Bmep = Imep- Fmep. Can you explain your question further? Which cylinder's Friction power are you talking about?
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  Gurvinder1993singh

  Gwg
• 

  amankishu4

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  In SI engines, no partial combustion takes places because octane rating of fuel is high and compression ratio is less. So fuel mixture won't auto ignite. And if partial combustion (fast rate of oxidation) happens then it will auto ignites complete mixture then knocking occurs which means there is some other problem with engine. Pressure developed without spark is called motoring pressure which may be of order 5-10bar and, with spark cylinder pressure can go upto 100bar or beyond depending on cylinder displacement.
  During cylinder motoring, unburned fuel can vaporise or go under slow oxidation which doesn't account for significant pressure increase. So fuel comes out of exhuast valve in vapor form thus increasing hydrocarbon emission any slightly CO gas too.