Just a thought...

Here's some cruise BSFC's of sub-1000 hp turboprops:

Solar 60 /130 hp - 1.20
Allison/RR 250 /317 hp - 0.73

Allison/RR 250 /500 hp - 0.66
P&WC PT-6 /500 hp - 0.67

BSFC gets somewhat better with size:

P&WC PT-6 /1020 hp - 0.58
P&WC PW127C/ 2130 hp - 0.52

How about designing a pilot and a main injector that install in a place
of leading and trailing spark plugs? - together with suitable ECU and
injector pump.

What's new here compared to JD's system, is that pilot flame and spark
should be on same body, and both injectors should spray in ~70-80 deg.
angle compared to injector body. That should be doable.

That makes a ~2000 USD kerosene modification - for stock engine! :)

John Deere's SCORE engine BSFC figures were somewhere around 0.5 lb/Hph.
That's not bad, since JET is cheaper than 100LL - especially in Europe.
And cost of engine is... well, cheapest real turboprops are starting
from abt. 200 000 usd...

If 0.5 BSFC with JET A-1 isn't enough incentive for some application,
further refining and Turbo-compound should lower the BSFC figure to
somewhere around 0.4.

Of course, there's other things that need and should be done first, like
firewall-forward kit and turbo-compound, but after those...

Cheers,
Petri


Mid West (UK) demonstrated a two rotor Wankel a few years ago running on JET
A1 using an injector engine. The only problem was starting from cold, but
the answer was simple, start the engine with petrol (gasoline) then once
running change over to jet fuel.Both fuels had oil added.

Peter Whitehead