[Ken522]

I dunno ... 5 cylinders means it burns more gas than a 4-banger ...

[Oldexpat]

Looks like many hydraulic pumps. Sounds to me like it has promise.

[Red Badger]

From their website:

What fuel types can a Duke engine run on?

To date most of our development and testing has been on gasoline of various octane ratings. Other commonly used SI fuels such as biogas CNG, ethanol, methanol, lpg could be easily tuned for with no physical changes to the engine.

We have done some SI testing on JP8 (AKA Jet A1 and kerosene). Initial results are very encouraging and we plan to do some more optimisation here as we learn more about the Duke’s unique characteristics. We expect that JP5 will also be able to be used in Duke engines with few changes.

Performance and BMEP - 3 litre Duke Engine

Performance test status on gasoline:

Torque: 339 Nm / 250lbft @4500 rpm (lambda 0.9), safe map spark.

BMEP: 11.8 Bar / 171psi

Power: 160 kW / 215hp @4500 rpm (lambda 0.9), safe map spark.

Significance of current gasoline performance status:
11.8 Bar BMEP is competitive with conventional SI engines.
3.0L torque output of 339Nm / 250ft/lbs is above that typically achieved by comparable conventional engines - due to pistons reciprocating at 120% of output speed, allowing a 20% higher output to be achieved at any given speed.
160kW power output is competitive with conventional SI engines of equivalent displacement and is currently achieved at only 4500 rpm.
V3i gasoline performance reported is below its real potential due to the lower Jet A1 compression ratio used and interim precautionary limit of 4500 rpm in this test phase (design target 6000 rpm).

Performance test status on Jet A1:

Torque: 292Nm / 215lbft @3500 rpm (lambda 0.88) detonation detected spark advance – 5deg.

BMEP: 10.2 Bar / 148psi

Power: 126kW / 169hp @4500 rpm (lambda 0.88) safe map spark advance.

Significance of current Jet A1 performance status:
Torque on Jet A1 achieved between 79% and 100% of gasoline baseline between 2000 and 4500 rpm.
These Jet A1 full load test results are considered particularly encouraging. The 10.2 bar BMEP achieved on Jet A1 is marginally above that of a Lycoming O320E comparator at rated power, operating on AVGAS. This is above the BMEP considered feasible with Jet A1 in conventional naturally aspirated spark ignition engines.

V3i Performance on Jet A1 is expected to increase significantly from this initially encouraging level due to operating at higher speeds with further combustion system and calibration optimisation.