The title may be a little misleading, but you should enjoy it. Here is a lawnmower mod that me and my old high school engineering program did for two years:
Yea, so its more of a hovercraft now than a lawnmower, but we used two lawnmower engines (5hp vertical drive in front, 10hp horizontal in back) and custom fabricated parts to make this beauty. Here are more pics:
That was the first one, code name: Hurricane. It had a max speed of 45mph (achieved by yours truly) and performed well on both land and water.
The following year the same class built another, more powerful one, with me acting as a student advisor. Here is the finished product, which we took to Chillicothe, Ohio, to race at the 2007 National Hoverally:
Me taxiing to, then waiting at the start line with my copilot watching. This one had a 10hp vertical on the front, and a 15hp vertical on the back. Due to the rear engine being vertical we had to create a system for it to drive the horizontal propeller for thrust. This cause most of our problems on race day, and ended up pushing us to last place in all our races. However, we were outclassed in the 25hp class that we participated in anyways due to the fact that most of our opponents used a 25hp single engine design, or a 22hp rear, 3hp front design to achieve maximum thrust. With this being our first race ever, we didn't really know what we were up against.
In 2008 my copilot and other racers went back with the white hovercraft, after severely modifying it, and took 1st, 3rd, and 4th in a variety of races. As far as the modding part goes, here are some pictures of our build process:
The plow plane, or bottom of the hovercraft.
Shaping the nose and lift duct.
Shaping the thrust duct.
Final thrust duct.
Skinning the Styrofoam with plywood for strength.
Finishing the lift fan. We buy the fan and the prop pre-cut, then we apply four to eight layers of epoxy and fiberglass for strength and protection.
Finishing the prop.
The harrowing adventure of trying to fit a full size, assembled hovercraft through a door at a public school...
Kinda like taking the little ship out of the bottle.
Out the door and on its way to its first proving ground test, which it didn't pass because the electric starts on the engine got wired to the dashboard wrong.
Feel free to ask any questions, and I have more pictures of the build process and other hovercraft that I may post later.
*Edit* Thanks for moving it, I saw the Misc Projects group almost right after I posted it. Dunno how I missed it. Also changed the name so people know what it really is.