The reason I don't like to lump the rotary in with alternative
engines is I don't consider it to be any way comparable with
automotive piston engines. Automotive piston engines are made
with cheap materials like cast iron and powdered metal.
The manufactures can get away with this because the engines are light
duty and rarely see over 50 HP. An aircraft engine on the other hand
is expected to deliver 150 HP or more hour after hour.

A Chevy LSx V8 is about the lightest duty car engine you can find while
weighing 500 pounds. It is rated at 400 HP in the Corvette while the car
needs only about 30 HP to cruise at 80 MPH. It has a cast iron crankshaft,
cast pistons and powdered metal connecting rods.
Here is a spec sheet from www.GMpowertrain.com.

In a real aircraft engine only the highest strength vacuum melted steels
and forged pistons are used for these parts for very good reasons.
Consequently there is a reason why car piston engines don't work in aircraft.
Every year at OSH a new aircraft application of the Chev LSx V8 appears.
The following year or so it is nowhere to be found. Chevy V8's last about
200 to 300 hours in aircraft use and then they self destruct in the hand
grenade mode without warning. Here is what could happen if the moving parts
of the engine are not designed for a 2000 hour fatigue life at aircraft
engine power levels. The 1500 to 2000 hours TBO of an aircraft engine is
there for very good inspection reasons. The moving parts are magnafluxed looking
for cracks that could lead to catastrophic failure.

Nobody inspects their alternative engines at 300 hour intervals
which is suggested by the types of materials found in automotive
piston engines.

Consequently these engines can fail catastrophically without warning.
I consider them very dangerous indeed.

Obviously the rotary is entirely different from a piston engine
and it has proven to last for at least 2000 hour in aircraft service
and it is not subjected to the type of reversing stresses that lead
to metal fatigue.

Paul Lamar ...No rotor no motor.

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