increase of compression ratio

vb_austin

vb_austin

@vb-austin-7DiNiW • Oct 25, 2024
can we increase the compression ratio of petrol?will the petrol can be sprayed in two stroke engine.?
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  • blacrobous

    blacrobous

    @blacrobous-Exhggm • Sep 23, 2009

    if that would have been possible then i dont think they would use carburator for air fuel mixture??
  • 4d1

    4d1

    @4d1-wARNWp • Sep 24, 2009

    vb_austin
    can we increase the compression ratio of petrol?will the petrol can be sprayed in two stroke engine.?
    Higher compression ratios will make gasoline(petrol) engines subject to engine knocking and this will reduce an engine's efficiency or even physically damage it.

    CR in a gasoline/petrol powered engine will usually not be much higher than 10:1 except for engines meant for racing purposes
    racing engines do not have a long life span !!

    p.s.
    *higher compression ratio requires a high octane fuel
  • vinitk

    vinitk

    @vinitk-Hr6tv6 • Oct 5, 2009

    vb_austin
    can we increase the compression ratio of petrol?will the petrol can be sprayed in two stroke engine.?
    Ans: Increase of compression ratio can lead to knocking.Knocking in petrol engines is pre-ignition of fuel-air mixture(i.e. before the piston reaches the T.D.C. the fuel-air mixture self ignites).
    Octane number of the fuel is the limiting factor.Hence to increase the compression ratio u should use a fuel with higher octane number.

    Nowadays in cars fuel is directly injected into the cylinder by a nozzle.
    Carburation is now obsolete in case of 4 stroke petrol engines.
  • manju_badri

    manju_badri

    @manju-badri-4Yduzj • Dec 2, 2009

    yes! we can use higher CR in si engines if we use higher octane rating fuel .still it can't be as high as CI engine CR(25:1)
  • mech.sasikumar

    mech.sasikumar

    @mechsasikumar-XnvXf4 • Dec 3, 2009

    yes, mostly all modern vehicles are having pressurised injectors for spraying petrol inside the cylinder so increasing compression ratio wont affect fuel spray..
  • namit.sahu

    namit.sahu

    @namitsahu-HMk9de • Dec 3, 2009

    vb_austin
    can we increase the compression ratio of petrol?will the petrol can be sprayed in two stroke engine.?
    by using a nozzle of different types we can increase or decrease the compression ratio..