Gnome Rotary Engine run

gipsymoth236k · 1 November 2006, 06:34 PM

Here's a great sound and video of a 160hp Gnome 9N Sopwith Camel (PJ's) in action:

YouTube - Broadcast Yourself.

Enjoy.

-Gary Sewall

PC777 · 1 November 2006, 06:59 PM

Quote:

Originally Posted by Breguet

Any chance of a small video? With sound?

Yes I would say there is a very good chance, I just have to do some editing and post a short movie up somewhere (youtube), I just need to get a bit of time to do it.

I will try do do something soon, glad to see some people are interested.

I have full access to this engine so I will take a few photo's from the rear (of the engine that is!!) as well if you like.

Regards

PC

Breguet · 1 November 2006, 09:02 PM

Here's the link to a model one running:

YouTube - Rotary Radial Engine Run

cfgray · 1 November 2006, 09:14 PM

Quote:

Originally Posted by gipsymoth236k

Gnome experts!
I own a 160hp Gnome 9N. Were they only French-built, or where they also built elsewhere?
Thanks for any information.
Regards, Gary Sewall

Hi, Gary,
The 50 h.p. 7-cyl. (two-valve, Greek letter) Gnomes, subsequent two-valve Gnomes and the Gnome Monosoupapes (80 h.p. 7-cyl. Type A and 100 h.p. Type B) were built under license in many countries in addition to France - Great Britain (Gnome Engine Company), Germany (Bayerischen Motoren Gesellschraft), Russia, USA (General Vehicle Company), Italy, and Sweden (Thulin). I don't know for a fact but would suspect that the later types such as your Type N were also license built.

By the way, I'm looking for a presentable (non-op) 7-cyl. 50 h.p. Gnome for a museum display, any help appreciated.

Best, cfgray

Taz · 1 November 2006, 10:28 PM

Gary- Fred Murrin has written an article on the Gnome 9N for OTF which will be published in the near future. He is also including photographs of one he overhauled, which I assume is the engine for his Camel. He goes into depth on how the two magnetos work along with the selector switch to provide rpm control. Told you that you needed to subscribe. We also have an original operators' sheet from and AEF unit on the 9N which will most likely go in the article.

cfgray- I know the U.III was a license built version of the double lambda, were the U.0 and U.I based on the later or earlier design?

Taz
Terry Phillips

cfgray · 1 November 2006, 11:02 PM

Quote:

Originally Posted by Taz

Gary- Fred Murrin has written an article on the Gnome 9N for OTF which will be published in the near future. He is also including photographs of one he overhauled, which I assume is the engine for his Camel. He goes into depth on how the two magnetos work along with the selector switch to provide rpm control. Told you that you needed to subscribe. We also have an original operators' sheet from and AEF unit on the 9N which will most likely go in the article.

cfgray- I know the U.III was a license built version of the double lambda, were the U.0 and U.I based on the later or earlier design?

Taz
Terry Phillips

Hi, Taz,
Well, I'm stating this from memory (always a risk) but I believe the Uberursel UR.I was the license built 7-cyl. 50 h.p. Gnome Omega, the UR.II was the license built 9-cyl. 80 h.p. single bank Lambda, and the UR.III was the license built 18-cyl. 160 h.p. double bank Lambda-Lambda. The Monosoupape engine were designated as "Type A" (7-cyl. 80 h.p.), the "Type B" (9-cyl. 100 h.p.), etc., to the familiar "Type N" (a 1918 example of which was the engine which became famous as the "Wandering Gnome" at Rhinebeck Aerodrome early this year).

By the way, the dual mag selector switch rpm control used on the Type N was an ingenious set-up. The different combinations of settings would power different cylinders, so the engine could be run (for fairly short periods of time) at intervals of full-rpm.

Early production Monosoupape Type A Gnomes had a handwheel-operated geared arrangement to change the valve timing in flight, which permitted some throttling, but the set-up was heavy and didn't work too well, so it was dropped.

Best,
cfgray

PC777 · 2 November 2006, 01:24 AM

Well here it is as promised, my first video attempt to youtube.

Hope it works out OK for everyone.

Here is the link:

http://www.youtube.com/watch?v=R_JMGO5NzuI

Regards

Paul

Breguet · 2 November 2006, 03:11 AM

Wonderfull! Thanks so much for that. Is this engine out of the AWM's Avro 504 (I heard it had gone to Adelaide)? Are they getting it ready to put into the old Red Devil?

Taz · 2 November 2006, 09:23 AM

cfgray- You have your terminology mixed up on the Ur (Le Rhone series) and U (Gnome series) Oberursels. See earlier post. The U.0 was a 7 cylinder engine of 80 hp and the U.I was a 9 cylinder engine of 100 hp. The U.II was apparently never produced.

On the 160 hp Gnome 9N, all cylinders fire on all four switch settings, just not as frequently on switch settings 1, 2, and 3. Some cylinders not firing on switch settings 1, 2, and 3 is a commonly held misbelief on the 9N. This ingenious switch architecture ensured spark plugs did not foul and that heat loads across all cylinders were kept identical. It also cut way down on the need to use the coupe/blip switch.

Taz
Terry Phillips

cfgray · 2 November 2006, 09:30 AM

Hi, Taz,
Ah, well, I should have consulted sources, rather than rely on my aging memory. Thanks for setting me straight and for explaining that ingenious selector switch arrangement in detail, it is even more remarkable than I had thought.
Best,
cfgray