wolit@rabbit.UUCP (Jan Wolitzky) (06/29/84)
On this morning's CBS radio "Newsbreak" segment, there was an interview with one Douglas Campbell, an 88-year old WWI flying ace. He described his Nieuport (sp?) as having been powered by radial engine in which the cylinders and prop rotated together around a fixed crankshaft, which was attached to the plane. Now, I'm not about to argue with one who was there, but I always thought that in a radial engine, it was only the geometry that was different, but that, as in a "conventional" piston engine, the cylinders were fixed and the crank did the turning. I can't figure out how you'd manage carburetion, valve actuation, etc., with the cylinders spinning around madly, or if you could, why you'd want to. Could someone out there enlighten me? Jan Wolitzky, AT&T Bell Labs, Murray Hill, NJ
djmolny@wnuxb.UUCP (Molny) (07/02/84)
Strange as it may seem, the old radial engines DID feature cylinders that rotated around a fixed crankshaft. Bear in mind that the internal combustion engine was a pretty new device back then. I'm not exactly sure how fuel got into the cylinders, but there certainly wasn't anything as fancy as a carburetor. In fact, there wasn't even a throttle! WWI pilots regulated engine speed by turning on and off the ignition. There was a button on top of the stick for this purpose. Unfortunately, fuel continued to spray into the cylinders when the ignition was off, and restarting the ignition after a long coasting period often resulted in a cockpit fire. Lovely machines. Regards, DJ Molny, ccom consultants, inc at AT&T Technologies ihnp4!wnuxb!djmolny
ths@lanl-a.UUCP (07/02/84)
The early "radial" engines in WWI did indeed rotate about the crankshaft. Probably the most notable was the LeRohne Rotary. I don't recall off-hand, the power output but I would guess it was about 110 hp. These engines powered many of the early French fighters. The torque on these engines was impressive as you can imagine. One other interesting note....there was no throttle in many of the configurations. You "blipped" the mag switch on and off to vary the power during taxi and landing phase. All other flying was "all-out". Next time you get a chance to see Earl Flynn in "Dawn Patrol" don't miss it. You can see all aspects of the rotary in action plus get some idea as to the amount of dirt and castor oil that smeared over the pilot during flight.
tackett@wivax.UUCP (Raymond Tackett) (07/03/84)
I think there was a terminology problem on the TV show. Radial engines
are simply those where the cylinders radiate from the center. They
were common on military aircraft and commercial airliners for many years.
Look at a picture of a Ford Trimotor for a good view of radial engines.
Some WWI aircraft had radial engines which spun the engine block as you
described. The idea was that the lightweight wooden propeller wasn't much
of a flywheel, but the engine block was.
Ignition timing is a piece of cake. A buzzer behind the firewall generated
a continuous spark which was fed to a wiper at the top of the firewall. Each
spark plug hit the wiper as it came by and got a shot of juice.
I never did figure out the carburetion.
There is a beautiful display of a rotary, radial engine at the Air Force
Museum, Wright-Patterson AFB, Fairborn, Ohio. Some of the cylinders are
cut away and the whole thing is turned slowly by an electric motor.
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Ray Tackettcfiaime@ihnp4.UUCP (Jeff Williams) (07/03/84)
More of interest concerning the early rotary engines. These engines used castor oil for lubrication. During WW1, the pilots walked with a swagger, not because of pride, but because of the effect of breathing vaporized castor oil for several hours. As another aside, late in the war, the rotary engine was relegated to a lesser place in manufacturing. If you had to use a rotary because of supply, you knew that your factory was out of favor. Tony Fokker was out of favor with the government for a long time. He not only was forced to use rotary engines for his Triplane, but they were captured from the French. The story is told that Fokker would pay a bonus to any pilot who wrecked an airplane that the engine could be salvaged from. There were two basic manufacturers during the war, Gnome and LeRhone. These engines were rated from 90 to about 210 horse power. Red line was 1250 rpm on most of them. At 1350 rpm, they would come apart. Frank Talman, the late movie stunt pilot, flew several planes with these engines. He also noted that replicas built with a radial engine, such as a Warner Scarab, would not fly nearly as well as with the rotary engine. It has to do with the slow turning propeller. However, he notes that left turns were difficult because of the torque of the engine. Question: is there anyone else out there with an interest in old aircraft engines? Jeff Williams AT&T-Bell Laboratories ihnp4!cfiaime
ntt@dciem.UUCP (Mark Brader) (07/05/84)
I have no details, but I remember reading some years ago of one interesting solution to one problem of the rotary engine. The problem, as mentioned in some earlier postings, is that the torque of the rotating block makes the plane's maneuvering qualities asymmetrical. The solution was to make the engine in two parts that rotated opposite ways! Needless to say, this monstrosity was soon found insufficiently reliable. Mark Brader
ted@teldata.UUCP (Ted Becker) (07/10/84)
*************** On several of the WWI vintage aircraft the engine did indeed rotate. First time I heard it I didn't beleive it either. Sopwith Camels and Sopwith Pups were the planes that I recall hearing about it. I recently saw some old film on TV that made it very clear that the entire engine rotated. Must have tremendous gyroscopic reactions.