Alternative engines

[Joe Piche]

> Maybe.  Don't most turbines spin something like 30,000 RPM?  It's a lot.
> And they don't really produce any torque at all until they get up to a
> substantial portion of that.  You'd need a 20:1 final drive ratio to get
> "normal" performance, so that won't do.  What I would recommend is a
> reduction before you feed into the transmission.  Before the clutch, even.
> I wouldn't trust most transmissions to take that much RPM on the input.

Using a standard jet engine is out of the question. Using a turboshaft
engine is relativaly easy. Something like the PT-6 (variations on
the engine produce 500 to over 1000 hp), with a low output speed from
the reduction gear box.

The allison 250, 400+ hp, has an output speed of 6000 rpm.

As for exhaust size, these engines don't need very large exhaust. Diesel
truck sized.

The most efficient way to run a turbine in a normal vehicle, would be
to have the turbine at a constant speed, and use it to drive a
hydralic pump with variable output, or an electric generator.

Problems with turbines. Parts cost a fortune, and once a part like a
turbine, or a compressors become time-expired, they tend to fly apart
like a grenade.

As well, turbine engines are fragile things. Doesn't take much to
completely destroy a compressor (especially axial compressors). Small
rock, dirt, etc.

Just my 2 cents.

Joe
(I'm a AME (aircraft maintenance engineer). I just completed 4 courses
on jet and turboshaft engines)