The Rise & Fall of the Radial Airplane Engine - History & Technical

The Inline 6 Airplane Engine : https://youtu.be/Su9WN0Pi04s Adept V6 vs Boxer 6 : https://youtu.be/RNy6dL3UqDs The Only Video You Need to Understand Propellers : https://youtu.be/hvboi6w1Z9A

Flew a Stearman with a Continental W670 for 30 years. The engine didn't leak unless it sat for a long time. Sold it to a museum In Madrid, Spain. I still miss the sound. My airplane was in the Movie "The Tuskegee Airmen". BTW, after an hour or two, the vibration made my stick hand numb.

I knew radials always had an odd number of cylinders. This is the first time I've heard why. Thank you!

There's nothing like the sound of a radial. Whenever one flies over, I'm in the yard looking...and my neighbor's in his yard, doing the same thing! LOL!

The secondary imbalance became a big thing on 18 cylinder radials, which being 180° out of phase between the two rows, resulted in a wobble motion in which the engine constantly tried to change the propeller’s plane of rotation. Pratt and Whitney as well as Wright ended up installing rotating counterweights (not exactly “shafts”) to counter the forces. It was killing propeller shaft bearings. The effect was discovered in around 1938 or 1939 when the R-2800 and R-3350 were in development.

NOTHING sounds like " aviation" like a radial engine...to my ears😊

Thanks for this informative video. My father was a fighter pilot in WW II, flying a P-38. Although this fighter had liquid-cooled engines, my father had flown various kinds of planes in training, etc., and he taught me quite a bit about about the different kinds of aircraft and their engines. When I was in graduate school in Athens, GA during the middle and late 1970s, I usually went home to the NYC area by air. There were commuter flights from Athens to Atlanta, and during the first few years I was in Georgia, I flew on these Martin 404 aircraft piloted by Southern Airways (even though most people seemed to avoid them!) because I recognized these aircraft as remnants of an era that would soon end. I used to sit where I could watch the exhaust manifold of an engine (which would glow, especially during takeoff) as well as the flames from the exhaust pipe (yellow due to the richer fuel mixture used during takeoff, then blue during the complete combustion when a leaner mixture was used during cruising). I had an altimeter, and brought it along during flights. I don't believe these planes were pressurized, but they didn't fly very high--my altimeter usually read about 5000-6000 feet. The larger jet aircraft, being pressurized, read about 8000 feet although they flew at altitudes 3 to 5 times that. As I recall, the smaller turboprops, which replaced the Martin 404s, typically flew at about 15,000 feet and were pressurized. Before the days of terrorist attacks, one could sit up front in a turboprop commuter and watch the pilots at work (it wasn't interesting to watch the engines with those aircraft)--I knew the altitude because I could see the plane's altimeter. Now I take my road atlas and track the progress of the flight--and sometimes I see interesting things on the ground that I decide to visit by car later on!

The radial engine is one of my favorite aircraft engines. As beautiful as, and as much as I love planes like the P-51 and Spitfire with their Merlin engines, water cooled V12s do sound great, but the radials sound absolutely BRUTAL and it is glorious. THE best sounding engine to me, to date, is the is the Pratt & Whitney R-2800 Double Wasp, and more to the point, as it is installed in the F4U Corsair. Heard a F6F Hellcat fire up, and it was a great sound, but when the Corsair started, it had all the attention. I was about 50 yards away and could feel, every, single, cylinder when they fired. From start up, I could count how many cylinders it was running on just from the thump in my chest. When it later screamed and roared passed us at likely well over 300 MPH, I could STILL feel the engine pounding me in the chest! I could hear the sound of FiFi the B-29 as she flew by from a couple of miles away and she still made a great noise too. I just realized, I have heard way more radials than I had originally thought......and most of them without being at airshows with the exception of the F4U and F6F.

Was told by a retired Boeing engineer years ago that radial piston -bore size maxed out due to the expanding flame front at the point of ignition in the cylinder not being able to complete the combustion before the exhaust stroke .

i love radials, honestly, best sounding engine for planes ever

About those Lawrence radials. Beside making radial aircraft engines, in WWII Lawrence also built some miniaturized radial engines of about 10 or 15 horsepower to power B17 and B29 APUs. Unlike radial aircraft engine the Lawrence APU engines had a vertical crankshaft with the cylinders arraigned around it in a horizontal position.

This blew my mind. I had no idea all the engineering that went into the radial engine. I flew in a four-prop plane as a kid and I remember the vibration and sound. Now I know why. What incredibly smart people. I get why it took Wright Aviation so long to work out all the kinks in their engines in the 1930s and 1940s. All this was done with slide rules and vellum.

Thank you! I've got Wasps on Beavers outside my window many times per day. Excellent historical perspective.

I remember assembling a W 670 in A & P school in the 1980s, it was an awesome experience. We took a trip last summer from Homer Alaska to Brooks Falls on a Beaver which is radial powered. The sights, sounds and low frequency vibrations were great! There is a rotary engine motorcycle from the twenties with the engine mounted in the front wheel too. Thanks for a great video!

Beautiful video. As an old shade tree mechanic Most of what I learned was by word of mouth and by rebuilding motors. It was a real treat to view this video about radial engines. Dad bought me a basket full of motorcycle parts in 1973. It was a 1968 Honda CL 350. I had the motor back in the frame and the motor running by about 7 PM. I later learned that its engine layout was nearly identical to an 1940s John Deere Model G Tractor!

P-47. Hold my beer.

I stumbled onto your video as I am building a Corsair model plane and the engine was not something I was familiar with. I found your wealth of information and presentation skills outstanding. While dealing with only the external parts of the engine build, I was fascinated to understand how complex yet elegant this engine is. Keep educating us, it great information. Thanks.

The main component beside the master rod that makes the radial possible is the cam ring. You should devote a hole video explaining it. The cam ring can turn either with or opposite engine rotation. The direction is determined by the geometrically possible number of lobes. A 9 cylinder will run with a 4 lobe cam ring turning opposite engine rotation at 1/8 speed. Or a 5 lobe turning 1/10 speed with engine rotation. It is the cam ring geometric relationship that determines the alternating firing order. The master rod and articulating rod relationship cause a slight timing and stroke length difference in the articulating rod cylinders. Timing is usually cured by a compensated breaker cam magneto. Ignition timing should be made with a properly wired magneto set to the master rod cylinder. That cylinder can be any convenient location.. On a M14P it is #4. The crankshaft counterweights usually have internal vibration dampers. The odd number of cylinders and other differences give the radial that sound. A little pedantic??

6:21 Oh wow! I always wondered but never knew how radials handled valve lifting. Now I know. That's cool, and the animation is very nice.

This video popped into my feed and you got all 15 minutes and 5 seconds, sir. Subscribed.