|This is a popular engine by Allied Signal called
a JFS 100. It is the starter engine for a larger
aircraft engine. It is a twin shaft or free turbine
engine meaning that the power turbine is not
directly connected to the engine turbine. It would
be similar to a torque converter in an automobile,
as the powerful gases produced by the engine drives
the power turbine and through a gear reduction, on
this particular engine, will produce about 90 horse-
power. It has a centrifugal compressor and an axial
flow turbine. It also has it's own starter/fuel control
system, and will start at the simple flip of a switch.
|I chose this engine because it is completely self
contained, easy to operate and is simple to convert
to a thrust jet engine. By comparing the picture on
the right with the one above, you can see that all
you have to do is remove all the power turbine and
it's gear reduction sytem and add an appropriate
exhaust nozzle. With the exhasut nozzle, you can
expect around 85 pounds of thrust. The completed
engine will weigh about 50 pounds.
|The starter and fuel system requires 24 volts to
operate, so I have two lawn mower batteries to the
right of the engine. The exhaust nozzle with an
inner cone is easily visible plus the ignitor at the
upper right can be seen. Having the fuel tank above
a hot engine doesn't seem the best location, but it
was there or in my lap. I chose there.
|View of the completed Kart. I have not decided on
a throttle yet. There are two ways it can be done.
You can modify the governor as I did on my GTP30,
or just bleed off some of the fuel going to the fuel
injectors (five of them). The engine was never
designed for long runs so has a limited amount of
oil reserve. Coolers can be added to extend running
time. At present, with no throttle, I have a switch
located on the steering wheel. When I am ready to
go, I flip the switch and away you go. To stop, just
flip the switch off and hit the brakes.
|Here is a view of the left side of the engine.
of the solenoid fuel valves are visible in the center
of the engine. The starter and governor are mounted
below the main housing.
|Here is a video capture of my first test run. The
view is of the engine as it fires off. When it gains
full rpm's, flames are not visible. Acceleration is
slow but continuous. Jet power is not like a wheel
powered vehicle. There are no "lower" gears for
getting started so it's like taking off in 12th gear.
But, a jet keeps pushing you at the same rate as
your speed picks up. I certainly had a limited area
to test the Kart, but once I find a safe and legal
place to run it, I will add more operation data.
Back to TurboJer Home Page