Lycoming’s 8-Cylinder Beast: The IO-720 Compilation

As much as the aviation world hypes up radial engines and V12s, a rather obscure offering from Lycoming is possibly one of the most unique (and best!) sounding engines ever built. The 8-cylinder IO-720 was essentially two 4-cylinder IO-360s bolted end-to-end. First fitted on the Piper Comanche 400 in the late 60s, it made its way to other airframes, primarily as an upgrade. Although the IO-720 was powerful, it was very heavy, guzzled fuel and cost a fortune to overhaul, hence limiting its sales. Nonetheless, it could be found on the following aircraft, featured in this compilation:
00:05 Beechcraft Queenair
4:49 Piper Comanche 400
6:53 Beech Twin Bonanza
8:28 Fletcher FU-24
11:03 Piper Brave
12:44 Helio Courier
12:58 Mike Patey’s Lancair Legacy
Credit to 24HALL for Excalibur footage:
/ @24hall
One of the most distinguishing features of the IO-720 is its distinct sound, emanating a rumble unique to 8-cylinder engines that captivates any avgeek’s ears. When combined with an augmentor, as seen in the Queenair and Twin Bonanza models, the IO-720 emerges as one of the most exceptional-sounding general aviation aircraft to grace the skies.
What are your thoughts on the IO-720?
Video Credits:
• N888EK Beechcraft Quee...
• Bemidji Airlines Beech...
• Cruising in a Excalibu...
• N888EK Beechcraft Quee...
• N888EK Beechcraft Quee...
• Excalibur Queen Air Start
• 1967 BEECHCRAFT QUEEN ...
• Excalibur Queen Air
• Beechcraft Queen Air E...
• N888EK Beechcraft Quee...
• Queen Air Takeoff
• Queenair departing FLL
• 1967 Queen Air 65 - Ol...
• nice day for flying ex...
• Bemidji Aviation Beech...
• Cockpit view Beechcraf...
• *LOUD!!!* Bemidji Avia...
• *LOUD!!!* Bemidji Avia...
• Bemidji Aviation Beech...
• Beechcraft Queen Air r...
• Eaa 2012 General Rodri...
• Video
• Video
• Video
• Video
• Piper Comanche 400
• 1964 Comanche 400 - 8 ...
• Hauling Balls in a Com...
• Comanche 400
• FLYING YOUR OWN PLANE ...

[@joshiasbaja3934]

You have no idea how much I enjoyed that sound!

[@aircraftadventures-vids]

Glad you enjoyed it! It's certainly one of my favorite engines (one of...as there's many, lol)

[@KyleMoses]

I love my 720 legacy! Definitely hard to beat.

[@v1rotait23]

Coming from New Zealand, we're the land of the mighty Fletcher FU-24 aerial "farm dump truck"! Now replaced commonly by the Cresco 600 with a PT6 turbine on the same airframes. I have some memories from my childhood of seeing some Fletchers roaring around the countryside, "down in the dirt" when on holiday around the South Island of NZ. The big 720 "growls" its way into the sky. With loving the sound of V8 Supercar racing, these big Lycomings sound just as good, with the added long blade supersonic prop tips cutting the air like a buzz saw! Thank you for a great compilation of new & old video of an enormous and now very rare engine!

[@nzsaltflatsracer8054]

I live in Idaho & have a low time 720 running on a stand. I bought a Piper Brave at a local auction for $600 that was crushed in a barn collapse from snow load.

[@patriciosilva1969]

What a distinct sound signature ! Wonderful

[@dekemmeterjacques-etienne8505]

Best and perfect sound !!!

[@aircraftadventures-vids]

Yes indeed!!

[@markjessurun7765]

Ow Boy I just Love that Sound of that 8 cylinder Beast, incredible !! I am in South America in the jungle and I was thinking of a io 720 in a Cessna 206 ?? But then I am a Poor Man !! ❤❤😅😅 Thanks for the video clip love it !!😊😊

[@Gump327]

That would make a perfect match

[@2snowgirl520]

Lycoming engines are better than any music. My dad flew a twin bonanza and a queen air. These sounds remind me of him.

[@davidduganne5939]

The Comanche needs "augmentors" like the Queen Air. That really makes a unique sound. Great video--I had forgotten there were a number of applications besides the Comanche and Brave. Thanks! (thought you had a video on Geared Lycomings too? )

[@user-qg6by9le2f]

Wow what a plane. It used to be called the 400 Shark nose.

[@e36s50b30]

I can’t help but somehow all Lycs have that agricultural sound. For me at least an old 180 or even better 310 with a 470 is the best sounding O engined aircraft.

[@thepurpleufo]

COOL

[@Pilotc180]

Great old engine when properly operated and maintained; kind of cranky to start when hot, but it gets the job done; you would have to be an Arab to afford the fuel burn and maintenance, and on takeoff the people 5 miles away know your going flying😀

[@davidpearn5925]

We operated one on paper runs. A pig to start hot in summer……..the starter motor had a hard life and sometimes a jump start was needed through the back hatch.

[@MattMorris481]

Now thats what I’m talking about the lancair if you don’t have a PT6 then it’s the 720.

[@ramenhausten]

Any Comanche 400 or brine Excalibur out there in need of a home? I would love to restore o e back to airworthy conditions ❤🎉

[@eugeneoreilly9356]

Wonder why they never made a turbocharged version?

[@ArgetalianAviator]

Have you heard of the Falcon XP?

[@aircraftadventures-vids]

Have not, what’s that?

[@ArgetalianAviator]

@@aircraftadventures-vids It’s a two-seater Canard ultralight aircraft introduced in 1982, it became popular within the USA, even Chuck Yeager itself flew it. But where it hit the top number of units was Argentina, most Falcons were imported to Argentina between the 1990s, and it became a big success within Argentine ultralight aviation. As of 2023 there are a few examples airworthy. It’s equipped with a Rotax 582 engine, and has a top speed of 75 mph, and can fly for about 2 full hours. Many Argentine student pilots loved it.

[@aircraftadventures-vids]

Ah ok, an ultralight. I actually do remember that one, yes. I'm thinking of doing a compilation of antique ultralights, which I find interesting. Tx for the suggestion. @@ArgetalianAviator

[@supremeflagship8965]

I wonder how Lycoming IO-720 sounds without propeller...

[@aircraftadventures-vids]

The sound of an explosion

[@RealWoutLies]

Saved the best for last.

[@AvgDude]

Those aft two cylinders must have cooling issues.

[@user-rk9wm6rn3b]

What hp is the 720

[@Helicopterpilot16]

400hp

[@altonkenne579]

Nah I prefer the 0-100 continental myself or even the 0-200

[@karldunnegan2689]

We'll all sleep better knowing that.

[@altonkenne579]

@@karldunnegan2689 I'm so happy for all those that can sleep better knowing that . I guess I did a good deed.