@ 750 rpms, how many combustion events per second?

Discussion in 'Engine Topic' started by BondoSpecial, Feb 21, 2011.

  1. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

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    Hi here's a dumb car math question...if my SBC is idling at 750 rpms, how many power strokes per second are occurring? I know there are 12.5 crank rpms per second @ 750 rpms and the crank has to rotate twice in a 4 cycle engine per complete cycle, but I want to know how many power/firing events there are per second @ 750 rpms?

    Thanks

    Steve
     
  2. frankz

    frankz Veteran Member

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  3. High Country Z

    High Country Z Veteran Member

    Sounds right to me.
     
  4. Twisted_Metal

    Twisted_Metal Moderator Staff Member Lifetime Gold Member

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  5. tmv36830

    tmv36830 Veteran Member Lifetime Gold Member

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    I am thinking 50 but I will be willing to bet someone will know for certain. This board is full of smart engineering type people.
     
    Last edited: Feb 21, 2011
  6. tmv36830

    tmv36830 Veteran Member Lifetime Gold Member

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    Let's try this.

    750/60=12.5 750 revolutions per minute divided by 60 seconds
    12.5/2=6.25 12.5 revolutions per second divided by 2 equal 6.25
    6.25X8=50 6.25 compression rotations multiplied by 8 cyclinders equal 50
     
  7. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

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  8. K5JMP

    K5JMP Veteran Member Lifetime Gold Member

    you burning a prom or something?:confused:
     
  9. BondoSpecial

    BondoSpecial Veteran Member Lifetime Gold Member

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    No I was messing w/ the z28 today and whether this engine has been carb or EFI, at idle one bank has a very slight puff-puff-puff and I'm wondering if that is one single cylinder maybe having an exhaust valve sealing issue... I made a video of the idle comparing both banks. I was curious if one cylinder was causing the puffing how many puffs per second I would get.
     

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