Crankshaft Orentation

Discussion in 'Lawn Mowing' started by JimQ, Aug 24, 2007.

  1. JimQ

    JimQ LawnSite Bronze Member
    Messages: 1,139

    OK. Help me understand this. It seems like most prefer a horizontal crankshaft engine. (myself included) But why? What make a horizontal crank engine better than a vertical crank in a Z?

    It seems like with a vertical crankshaft engine, you would get a lower center of gravity and eliminate the mule drive to the deck.

    So, why guys? Why is horizontal shaft the way to go?

  2. Envy Lawn Service

    Envy Lawn Service LawnSite Fanatic
    Messages: 11,087

    Vertical IS the way to go for those reasons in my opinion.
  3. barnard

    barnard LawnSite Senior Member
    Messages: 618

    It's not vertical is for the reasons you mentioned. Envy hit it.
  4. lawnspecialties

    lawnspecialties LawnSite Silver Member
    Messages: 2,524

    With vertical shaft, you don't lose as much horsepower between the engine and the blades.

    Why most engine manufacturers build more horizontal than vertical is beyond me.:confused:
  5. SproulsLawnCare

    SproulsLawnCare LawnSite Senior Member
    from IN
    Messages: 365

    I agree that vertical shaft would eliminate the mule belt and all. But, I'm just guessing that it is easier and cheaper to manufacture a horizontal engine with the higher horse power, and still get the lubrication to flow properly so that the engine last longer. The oil can be pumped to the top of the engine and then flow over all of the parts on it's way to the bottom.
  6. Richard Martin

    Richard Martin LawnSite Fanatic
    Messages: 14,698

    If that was the way the lubrication system worked that would be a good idea. Unfortunately it's not so that idea is out the window.

    Whether the engineers pick vert or hor is simply personal taste. Do we want to drive the hydro system off of the front of the engine and the mule drive off of the back ala Exmark style? Or do we want to drive everything off of the bottom of the engine ala Dixie Chopper style? Sometimes space requirements dictate an engine's orientation.

    Ask yourself this....

    Why does Ferris turn some of their walkbehind engines 90 degrees compared to every other manufacturer?
  7. JimQ

    JimQ LawnSite Bronze Member
    Messages: 1,139

    It shortens things. Same with some Z's.
  8. paolaken

    paolaken LawnSite Senior Member
    Messages: 699

    cylinder walls and pistons wear more on one side on a vertical engine compared to a horizontal.
  9. barnard

    barnard LawnSite Senior Member
    Messages: 618

    So thats why porsche subaru and other boxer engines wear out so fast.Don't forget those BMW cycles.OH yeah and Honda goldwings.
  10. LCPullman

    LCPullman LawnSite Senior Member
    Messages: 589

    And how about the Hustler Trimstar. Problem is, if they leave the crankshaft centered on the mower, it throws the side to side mower balance off. They should move the engine over and center the weight on the mower.

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