[Niteflyr]

An early example: a turbo-compound engine collects all of the exhaust gasses and runs them through a turbine, with all of the power generated going back into the crankshaft and ultimately to the propeller. It differs from a turbo-supercharged engine, which uses exhaust gas energy to increase the pressure of incoming air. Work on this particular engine began in about 1944 and continued until 1946, when Allison asked that it be canceled because turbine engines had greater promise.

Allison V-1710

[Nathan Zachary]

That connection at the crank is NOT turbine power going back to the crankshaft, That’s one stage of this compound turbine POWERED by the crank. you can see the boost side tubing running to the intake side top rear of the engine, as well as the exhaust side pipes running to the back of the unit from both sides of the engine to a “t” joint. The crank drives an secondary turbo charger which compresses the compressed air from the primary turbocharger at the rear.