Big radial engines in full song!

Super Constellation take off at dusk.

R-3350s are each fitted with three power recovery turbines (PRTs). Each shrouded PRT is turned by the exhaust of six cylinders and transfers its energy back to the main crankshaft through a fluid coupling, thereby recovering what would otherwise be wasted energy. At take-off, each PRT contributes up to 150hp, adding around 450hp per engine on takeoff. The actual exhaust stacks are only about 2 feet long, hence the unburned fuel/flames out the stacks under full power, which was 59.5 inHg and 3,400 horsepower with 115/145 gasoline. Since 115/145 is no longer available, my understanding is they have derated the engines to something in the 2800 horsepower range and lower pressures.

In this picture, the item circled in red is the actual short stack on an R-3350 installed on a Connie. The lower stack is removed for maintenance apparently…


TBT… — 19 Comments

  1. And they sound wonderful when you are lucky enough to hear them pass overhead.

    I sorta remember reading that Fifi did the PRT engine conversion quite a few years ago.
    And the Skyraider has the same engine.

    I’ve see the 3350 cutaway for display and there is a huge number of moving parts inside those engine.

    https://www.flickr.com/photos/[email protected]/9428483220

    And perhaps the last word in huge radials is/was the Pratt & Whitney R-4360 Wasp Major.

    • There is a whole section of cut-away engines at the Udvar-Hazy branch of the NASM at Dulles. Just another reason to go back for another few hours.
      Several years ago I was mowing the law. Had headphone on. Still heard something “different.” Looked up and saw a DC-7 climbing out of IAD. NOTHING sounds like 4 huge radials with a full load.

      • Stretch. If I remember right, one of the cut-away engines at Udvar-Hazy is the R-4360. Now that is an impressive engine.
        The sound of large radials will bring us out of the house on the run, and that caused some consternation during a family gathering!

  2. Never has so much material gone over my head in such a short time. :^)

    Damn boy, you fly boys – er – persons sure do know your stuff.

  3. That is such an elegant plane. I wish we still had fleets of those beauties…

  4. You can really love an airplane like that. It’s like going to the National Air Races at Reno, where the sound, the smell, the horsepower and the flying envelopes the environment. There is something about it that can not be duplicated. The Super Connie was one of those racing planes, thinly disguised as a hauler.

  5. Nothing like the sound of multiple radial engines. I was out and about a few years back when I heard that sound approaching. Looking up I saw the unmistakable profile of a B-17 flying overhead. Made my day.

  6. That was beautiful music to start the morning off right. Could almost smell the exhaust, whipping across your cheek in a hot gust on a chilly ramp…

  7. Love that sound, it just grabs hold and wakes you up. My surprise was hearing the multiple rotary roar, and looking up to see a B-24 on final for a tour stop.

  8. All- Thanks for the comments. They were great birds, quirky but great! 🙂

    Posted from my iPhone.

  9. I’ll let other bloggers sing the praises of in-line beasties, but me? Give me the joyous voice of a radial any day. Big or small, all are very distinctive.

    One day, wandering around my socialistic hell of a city, I heard the low roar of three small Wright radials. Lo and behold, some vision of an ancient past appeared, an actual Ford Trimotor.

    Working near the approach of local airfield, I could hear when various warbirds or other radial lovelies arrived. Which usually meant me eating in the car while driving the back lots of said local airfield to go visit the aviation unit and spy what legends were now present. Ah, the good old days.

    Connies and SuperConnies were never meant to be on the ground. They always looked like some flying version of a greyhound, almost like just their looks added 50mph to their speed.

  10. The most beautiful plane ever built!!! I earned my flight engineer’s ticket on that bird, and I have a 1/10 hand carved model of one of those sitting right beside my chair. Although it is defaced with the upper and lower Radomes that got put on them so all those AW types could go see what flying was all about! (Just kidding Jim)!
    That sound just makes me homesick as hell for those great old days!

  11. Beans- You’re NOT the only one, trust me!

    Ev- I remember seeing that model and commenting that I had a few hours in them. We had the last 2 at Glynco, flew one to the museum, the other to Key West and gave it to VAQ-33. Smooth flyer with all that wing flex, unlike the P-3!!!

    • I didn’t realize how nice it was to fly in the Connie (VQ-2) until I flew in the C-130 (VQ-4) and P-3 (just transit) (VP-10) they beat you up bad.

  12. Every now and then I get to listen to four Pratt and Whitney’s go overhead and I get giddy, like at the opening of 12 O’Clock High.

  13. C’mon, folks – while I truly love the sweet sound of radials and will be the first to ditch whatever I’m doing to run outside when I hear one (or four), you can’t tell me that you don’t also get a little bit goosebumply when you hear the roar of a Merlin + the whine of its supercharger as it blasts by. What I’m saying is, they are ALL good and sweet!

  14. As an AC&W tech back in the ’60’s in the AF radar squadron on the NAS at Key West, I got a go-along ride on one of those RC-121(?) radar birds for a shift(nobody else wanted to go – just because they went up and fly through the Gulf straits between Cuba and Key West I suppose…). That was a serious plane ride.
    But I still prefer the sound of four sync’d Merlins on a Lanc, heh, heh.

  15. My understanding is that my father worked on those engines on Navy Connies at Pt Mugu Naval Air Station. EC121’s