Not the best quality image originally shot on slow ISO film years back, and recently digitized, but this photo gives you a look at one of the four air boats that I built in the machine shop (Eastside Machine) my dad and I operated years ago. I kept this one airboat for myself, and sold the other three as they got built.
The flat bottom aluminum hull is 16' in length, powered by a highly modified 110 horsepower 6 cyl opposed air-cooled corvair engine, turning a Banks Propeller Company laminated wood propeller with stainless steel leading edges, especially designed for the 110hp corvair engine.
The pitch of the propeller governs the engine to maximum of 3000 rpm at full throttle, giving the air-boat a top speed of 45mph.
When I say "highly modified" I am making reference to all the mods made to the engine (externally), to allow it to become an air boat engine.
The aluminum bell-housing had to be cut off with a vertical metal cutting bandsaw, leaving the newly formed crankcase end cover behind, a new starter mount for starter had to be fabricated, along with a new ringgear assembly, crankshaft/propeller adapter machined, all the air-cooled shrouding was removed, the manifolds were swapped from one side to the other allowing the exhaust to exit the front of the engine because of the close proximity of the exhaust manifolds to the propeller. An oil-cooler was installed, along with a larger capacity finned aluminum oil pan, waterproof ignition was installed on the engine as well.
Interestingly enough, and although the three airboats built and sold were powered with re-conditioned corvair car engines, the one airboat built for myself as seen above, was powered with a brand new corvair crate industrial engine originally meant to be installed in a hovercraft.
This engine came with waterproof wiring, that included braided protective shielding on the sparkplug wiring, as well as covers over the sparkplugs, similar to that found on a aircraft engine. The ignition coil also was mounted in a waterproof housing. This engine also had a more robust alternator mount, with the drive belt also driving a 1000 cfm cooling fan mounted at the top of the engine, that flowed cooling air over the cylinders. If the belt blew for whatever reason, a switch tripped, causing a warning light up front on the operators panel to activate.
This engine also came with an oil cooler already installed, and a extra capacity aluminum finned oil pan in place, with the crank end of the engine missing the bell housing, unlike the car engines that I made the necessary modifications to, allowing the propeller adapter to be bolted to the crankshaft.
The air-boat ready to run weighed 800 lbs all up, and was very maneuverable with the twin air-rudders each measuring 24" x 36" in size. The air-boat with its corvair engine that had shorty motorcycle mufflers mounted on the ends of the custom bent exhaust system was impressive to hear at speed needless to say!
If I must say so myself, the pedestal mount for the switching and gauges, the control stick for the rudders, along with the throttle mounted up top of the rudder control, made the air-boat a blast to operate!
The seating used were formed fiberglass padded buckets meant for car racing.
This photo was shot on the Red Deer river east of Drumheller in the badlands, my favorite river to run the air boat on. The many sandbars were of no consequence, as the air-boat as seen here with 2 people on board (my brother-in law at the helm, myself shooting the photos) , and at full throttle could traverse a 100' sandbar! The air-boat sat 5 people, two up front, and 3 just in front of the engine.
This air-boat made for a terrific fly fishing platform on the Bow, as you could still-drift down stream while casting a fly-line from the front deck, and when it was time to go home, you started the engine and blew your way back up stream.
The beauty of it was that the current had no effect on the air-boat, and in-fact you could fly upstream, as the current gave lift to the hull allowing it to skim the surface, while the air propeller cut a hole in the wind pushing the airboat through!
Expand the photo for a closer look.....