LHD-12F
Engines



    And here it is.  The guts and glory of the LHD-12F.  A 20 hp Honda, V-Twin.  She's 100 lbs of pure hovercraft excitement.  Hopefully by April 20th, she'll be turning a 48-36 prop.   I picked this baby up from Northern Tool and Equipment through my college roomie.  I won't say exactly how much I paid for it.  Lets just say, I saved enough to buy a lift engine and then some.  The lift engine of choice today is an 8 hp Briggs vertical shaft.  The 8 hp weighs in just over 50 lbs.  I change my mind on the lift engine almost hourly.  Do I want electric start, 8 hp, 10 hp... Then I think, I can extend the pull rope into the cockpit, and save the money.  We'll see what happens in the next week or so when I'm ready to buy.

    Well, I decided to go with a 10 hp, electric/recoil start Tecumseh.  I went with the 10 hp because it weighs just as much as an 8 hp, and will allow me to run it at a lower RPM which should put less wear on the engine.  After talking with a mechanic at Northern Tool, I learned that the 8 hp briggs were burning out from people mowing on an incline Oil wasn't getting to the main bearing.  That's not good, as the lift engine will be sitting on an incline for the rest of its hovering days.  I called up Tecumseh and talked to a factory technician.  He told me that all Tecumseh vertical shaft engines have an oil pump which allows the engine to run up to a 20 degree angle, 30 degrees intermittently.

    The engine is now mounted on the frame, waiting for sheaves and a prop.

    Thrust drive semi installed

    Lift engine is installed and going strong

    Thrust drive assembly

    This is my the thrust unit.  Because of the muffler on the engine, I couldn't just attach the bottom sheave to the shaft, so I had to extend it.  I personally love how the whole thing turned out.  Because of its overall length, I lost some cockpit space, but it brought the weight of the engine forward, balancing the craft.  Notice the idler pulley used to tension the engine.  I stole the idea off of Dennis Alm's Weber Hovercraft.

    Notice how far spread everything is.  I could have made it more compact, and perhaps I will in the future.  For now, it works out fine.  Again, it helps balance the craft.  Soon (06-04-2002) I'll reroute the exhaust manifold and make a more compact drive train, connecting the belt directly to the engine shaft.

    Here's a more detailed shot of the belt tensioner assembly
 
 

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