Just to keep the TCP discussion alive, I recently got this about some sort
of variant on the R3350.
What versions had PRT vs TC vs none at all? Who made them, both CW and P/W,
and ?
Marc Wiese

Subject: R-3350-93


Marc, I flew the 3350-93 for 2000 hours on Lockheed 1049 and 1649
Connies in the AF. That engine was a mechanical monster. At the time the
air lines majored the engine at 1000 hours but budget limited us to life
of the engine until failure. We never had an engine live past 1000
hours. I had 33 engine losses in 36 months, all of them far,far out over
the North Atlantic and over the ice cap. Less than 3 good strong engines
was a ditch condition! I was once down to 2.5 engines that did not end
pretty on Cape Cod. Our wing had several aircraft with engine fires over
the water and the Connie had a magnesium main spar that burned readily!
We lost four aircraft into the N. Atlantic with high losses. Not a happy
time!

Chuck

Chuck who? Was he a flight engineer?

You hear different stories from different people. Some say they never had
problems. Curtiss Wright claimed the TBO was 3000 hours. I think a lot
depended on the skill of the flight engineer. Some say they lost an engine
but they still made it to their destination. Curtiss Wright claimed 9000
engine were built with
over 7.5 million accumulated flight hours. Don't forget that technology was
60 years ago. I think Hurant below was a flight engineer.


Paul Lamar

-------- Original Message --------
Subject:        R3350
Date:   Sun, 7 Dec 2008 10:26:32 -0600
From:   <hkaribian
To:     <rotaryeng@earthlink.net>



The 3350 was leaned to 10% BMEP under a certain threshold of power (I
don't remember what it was) because of the power enrichment valve in the
carburetor. Above that power setting, but below METO (maximum continuous
power setting below takeoff power) and climb power, you used "Auto Lean".
The two injection pumps, initially, were connected with a synchronizer
bar that would change with temperature and vibrations but were later
replaced with flow dividers that equalized the fuel to each cylinder.
The engines were BMEP or manifold pressure limited on takeoff, whichever
limit was reached first, and you shifted to high blower when you ran out
of throttle at low blower in climb. Karibian

Bob Buck (wrote Weather Flying and an interesting autobiography) was a
captain and chief pilot for TWA and flew Connies (among lots of other
types).  My recollection of his comments were that the engine
reliability was crummy when running in the high ratio blower setting,
but was excellent when running in low blower.  I don't believe the
problem was in the TC, but more likely in thermal management.  He said
that TWA's operation just lived with the reduced performance (slower
cruise speed) at high altitude - running low blower.  He flew some of
the longest Connie missions - from the west coast of the US to London.


Regards,

Matt-

Curtss Wright had a lot of problems with the exhaust valves. Most of the TC
development money was spent making them live. If an exhaust valve broke
up parts of it would go out through the exhaust pipe and take out a turbine.
The flight engineer was instructed to shut down the engine to prevent
further damage. The Air Force Connies had large radomes that increased the drag
so performance on 3 engines was more marginal.

Need I mention the rotary has no exhaust valves :)

Here is a another good book on the subject.

"Lockheed Constellation" by Stringfellow & Bowers Motorbooks ISBN 0-87938-379-8. Therein the descriptions of the TWA nineteen hour non-stop flights from San Francisco to London and twenty three hours, nineteen minute flights London to San Francisco are described.

Paul Lamar