"Morgans" wrote in message
...

"Dale Scroggins" wrote

The SmartCar aluminum diesel engine and the Toyota Yaris engine (Europe,
aluminum diesel) might be good candidates for small aircraft. However,
this Subaru seems to be an ideal candidate since its power and weight
specs fit so many available airframes. PRSUs are also available. I
suspect we will see these engines installed fairly quickly in European
experimentals.

No need for a PSRU. The torque band makes it perfect for direct drive.
--
Jim in NC

It's going to need a starter; diesels are hard to hand prop. And the engine
is not likely designed to handle thrust and gyroscopic loads. So, because
of starter placement and need for a well-supported prop shaft, a nose-piece
casting with bearings and a prop shaft will be needed. Incorporating
reduction gearing (or belt) and a device to smooth power pulses wouldn't add
much additional weight.

The torque curve isn't flat to maximum power. If a fixed-pitch prop is
installed that is efficient at low RPM, the engine may not be able to make
take-off RPM without a bit of mechanical advantage - or variable pitch,
which leads back to the PSRU. Since Subaru is hinting that a 200 hp version
is on its way (giving even better hp/weight ratio), a variable pitch prop
should be considered.

DS