I did find out that my flight line neighbor was a flight engineer on the
turbo compounded Connies and boy did he have a mouthful to tell me
about those engines. I believe he said the blow down turbine blades were
made of tungsten and that the engines often caught fire. He said the
turbine compound helped at altitude but it was the huge turbo-chargers
with the 52inches of boost at take-off which personally tickled him.

My impression was the turbo compounding system as designed for the
Connies was not very reliable. He mentioned on one four city domestic
freight run they once lost and replaced an engine on each journey leg.

The later larger four row radials engines didn't use the turbo-compound
concept.

Not to worry. We have a much better choice of alloys with off the shelf
components, and O yeah, no exhaust valves to deal with.



Doug Fir

Flying around USA at the speed of time.

The R-3350 did not have turbo chargers and the blades were not tungsten
:) It did have centrifugal superchargers.

BTW Your sweater is going out to Flagstaff today.

Paul Lamar ...No rotor no motor.


I had one engine failure in 3200 hours in a Connie and none in about
1000 hours in DC7's. I learned the civilian trained flight engineers
didn't understand the R 3350 TC near as well as the military trained FE's.
The manifold pressure was boosted by a two speed engine driven
centrifugal super charger and the engine power was limited by MAP or
BMEP, whichever came up to the limit first. Karibian



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