Questions on Horse Power

Discussion in 'General Questions' started by Kestrel Motors Inc., Oct 16, 2011.

  1. Hey,
    I have a 1 1/2 horse Clinton engine. I looked up motorbike laws in NE (where I live) and bikes are considered mopeds here. In the laws, it said that it couldn't be more than two brake horsepower. I don't understand what a brake horsepower is and if my engine is under that. I don't know how many cc's it is... Answers would be great, thanks guys! :D

    Kestrel Motors Inc.

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  2. professor

    professor Active Member

    As far as I know brake hp is the output on a brake dynomometer. I would not worry about the rating. That engine is a real old timer, probably as old as me.
  3. HeadSmess

    HeadSmess Well-Known Member

    indicated as versus brake horsepower.

    indicated is a theoretical, harks back to steam engines when you could have a pressure guage on the cylinder and work out the "indicated" horsepower by the cylinder pressure/cylinder volume etc.

    and yep, brake horsepower was when its hooked up to a brake. i think its what it can start turning with, not how much it takes to stop it turning.

    these days? a HP is a HP is 750 watts approx, or 30000ft-lb/min

    ps is slightly different but close enough to not matter

    0.75 Kw is 1 hp...

    ooooh, nice n rusty :D i like that engine muchly :D though i prefer my 1926 b&s with OHV :p
    Last edited: Oct 16, 2011