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Taz · 22 August 2006, 09:17 PM

Ross- The engine you are looking at is Ur.II serial number 2968 from the National Museum of the USAF. It was originally fitted to Fokker E.V 108/18 and apparently was brought into the US from Germany post WW-II. It was not fitted to one of the E.Vs/D.VIIIs tested after WW-I in the US at McCook Field in Dayton, OH.

Late model Ur.IIs like this had steel intake tubing, but nearly all the Ur.IIs fitted to the Dr.I had copper intake tubing and should be painted that way. Langdon Badger and I have been unable to figure exactly which engine changed to stainless steel from copper, but MvR's 425/17 used copper tubing and it was serial number 2478 and this is 2968, so somewhere in there. In service the engines did not look so shiny because of castor oil staining. A photo of MvR's engine in Ferko's Richthofen from the back side looks much darker. It is easy to tell the 80 hp Le Rhones from the 110/120 hp Le Rhones because the intake pipes are on the front of the engine on 80 hp engines instead of on the back as on 110/120 hp engines. Oberursel never produced an 80 hp version of the Le Rhone 9. All the 80 hp Le Rhones had copper intake tubing, as does the one in the other photo you posted.

Le Rhones transitioned to stainless steel from copper much earlier than Oberursel, so a Dr.I fitted with a Le Rhone had a better chance of having stainless steel intake tubes than an Oberursel. Another data point is that both prototype Triplanes F.I 102/17 and 103/17 had Le Rhones with copper intake piping. The Oberursel Ur.II had not finished qual testing in August when the two F.Is came out.

Since I buried you in too much detail, we will leave how you visually identify an Oberursel vs a LeRhone for another time.

Incidentally, the web site you posted has a an Oberursel U.III, a Gnome based, twin row, 160 hp, 14 cylinder engine from the Fokker E.IV and D.III misidentified as a Ur.III. The Ur.III (r for Le Rhone) was an 11 cylinder, large diameter, single row rotary of 145 hp or so. You might contact the webmaster.

Taz
Terry Phillips

22 August 2006, 09:17 PM	#4 (permalink)
Taz Forum Ace Contributor Join Date: Sep 2004 Location: Albuquerque, NM Posts: 2,738	Ross- The engine you are looking at is Ur.II serial number 2968 from the National Museum of the USAF. It was originally fitted to Fokker E.V 108/18 and apparently was brought into the US from Germany post WW-II. It was not fitted to one of the E.Vs/D.VIIIs tested after WW-I in the US at McCook Field in Dayton, OH. Late model Ur.IIs like this had steel intake tubing, but nearly all the Ur.IIs fitted to the Dr.I had copper intake tubing and should be painted that way. Langdon Badger and I have been unable to figure exactly which engine changed to stainless steel from copper, but MvR's 425/17 used copper tubing and it was serial number 2478 and this is 2968, so somewhere in there. In service the engines did not look so shiny because of castor oil staining. A photo of MvR's engine in Ferko's Richthofen from the back side looks much darker. It is easy to tell the 80 hp Le Rhones from the 110/120 hp Le Rhones because the intake pipes are on the front of the engine on 80 hp engines instead of on the back as on 110/120 hp engines. Oberursel never produced an 80 hp version of the Le Rhone 9. All the 80 hp Le Rhones had copper intake tubing, as does the one in the other photo you posted. Le Rhones transitioned to stainless steel from copper much earlier than Oberursel, so a Dr.I fitted with a Le Rhone had a better chance of having stainless steel intake tubes than an Oberursel. Another data point is that both prototype Triplanes F.I 102/17 and 103/17 had Le Rhones with copper intake piping. The Oberursel Ur.II had not finished qual testing in August when the two F.Is came out. Since I buried you in too much detail, we will leave how you visually identify an Oberursel vs a LeRhone for another time. Incidentally, the web site you posted has a an Oberursel U.III, a Gnome based, twin row, 160 hp, 14 cylinder engine from the Fokker E.IV and D.III misidentified as a Ur.III. The Ur.III (r for Le Rhone) was an 11 cylinder, large diameter, single row rotary of 145 hp or so. You might contact the webmaster. Taz Terry Phillips Last edited by Taz; 23 August 2006 at 06:49 AM.