Small Engines (Lawn Mowers, etc.): converting a lawnmower engine for a hovercraft, belts and pulleys, horizontal shafts

Question
I could see how this would be fairly easy with a horizontal crank motor, however, my real question is, is there anyway to alter a vertical crank so that it will be able to spin the fan  , (horizontal i suppose)in a cost/work/power efficient way? Thanks, I really appreciate it.

Answer
Belts and pulleys could work but it would be easer to use the correct engine.  Horizontal shafts run side-to-side, vertical shafts run top-to-bottom.

I'm assuming the vertical shaft would have the fan bolted directly to the crankshaft.

You can not turn a horizontal engine sideways...it will not oil.
What size engine do you need?
Eric