Reproduction Rotaries?

[D.A.]

I didn't want to hijack anyone else's thread so I started this one.

There have been reproduction Rotaries mentioned on other threads but I can't find any info on what they are, who is building them, were they successful, and so on.

Does anyone have any info, data, links, prices, firsthand experience?

Thanks in advance.

[Laserlloyd]

Hi D.A.,

A good friend to some of us here is Fred Murrin and he had gone to New Zealand to reproduce the Oberursel a project for there use. I don't think they are publicly available but if they are wow what an engine...

The Vintage Aviator

If you look at all the project they have you can start to get an idea on what it's all for.....

Lloyd...

['14-'18aviationcollector]

Hi D.A.,

I know a replica builder who is having most of the parts for the 110 HP le Rhone reconstructed. I suggested to him that he should make extra parts available for sale, and he seems to be agreeable about this. I don't think he is having the crank cases reconstructed, but I know someone who would be able to achieve this, and I will approach him about the crank cases at some point. My friend also had an 80 HP le Rhone but he sold it unfortunately (fortunately for the buyer of course - but I won't be able to be involved in measuring it and having parts re manufactured). I was going to mention the availablitiy of rotary engine spare parts on this forum, and I will provide more information as it becomes available. Ultimately of course the plan is to progress from manufacturing and selling / trading spare parts to manufacturing and selling / trading complete engines.

Cheers,

David.

[Joe Perkel]

Originally Posted by D.A.

I didn't want to hijack anyone else's thread so I started this one.

There have been reproduction Rotaries mentioned on other threads but I can't find any info on what they are, who is building them, were they successful, and so on.

Does anyone have any info, data, links, prices, firsthand experience?

Thanks in advance.

D.A. (Dave)

You may not be aware but, the New Zealand effort is very likely as a result of Peter Jackson's (Lord of the Rings Director) avid interest in WWI aviation. Imagine for a moment what you yourself might do with such resources, so such an organization is not such a surprise result. Of course, you don't dump all of your money into this yourself, you set it up as they have and stand by to harvest the occasional fruit.

Our customers are generally private collectors and museums. We are currently building aircraft and overhauling engines for customers in Australia, New Zealand, Europe and the USA.

Not a bad gig eh? Would love to be pals with Mr. Jackson!

[D.A.]

Originally Posted by Laserlloyd

Hi D.A.,

A good friend to some of us here is Fred Murrin and he had gone to New Zealand to reproduce the Oberursel a project for there use. I don't think they are publicly available but if they are wow what an engine...


Lloyd...

Oh my goodness. I went to their website and their work is incredible! I've been an A&P for over 30 years and I'm in awe of what they've done/do. The effort they put into EVERYTHING they do is amazing. I'd bet they have more manhours into their run stand than most people have into their flying Graham Lee replicas.

Thanks for the link.

I do have a question though: Watching them run the Oberusel, it would appear that they have incorporated a workable throttle into their program. It's my understanding that the Rotaries did have a throttle of sorts, but you basically didn't use it. You got the engine set to run at full RPM and blipped it from there so you didn't fowl up your power settings and adjustments. However, in the video, they seem pretty proud of the function of their throttle. The camera focuses on their throttle lever and the engine responds great to different advancements. Are they running a useable throttle?

Again, WOW!

[John McKenzie]

Hello ...Only one person makes the complete Ur 2 , same way like they were made originaly and to original manufacturers drawings .......He is THE expert on engines , his name to the Forum is Franzkait from Germany....Look up "Oberursel Ur 2 reproduction" on this website ...He is NOT a billionair with facilaties - money no object , he is a REAL engineer ,..Udo knows more about this subject than all the others put together !......John

[Lufbery]

Originally Posted by D.A.

I do have a question though: Watching them run the Oberusel, it would appear that they have incorporated a workable throttle into their program. It's my understanding that the Rotaries did have a throttle of sorts, but you basically didn't use it. You got the engine set to run at full RPM and blipped it from there so you didn't fowl up your power settings and adjustments. However, in the video, they seem pretty proud of the function of their throttle. The camera focuses on their throttle lever and the engine responds great to different advancements. Are they running a useable throttle?

Again, WOW!

Throttles and rotaries are a very interesting and somewhat complex topic. The short answer is that it depends on the type of engine. What you stated above is essentially correct for the Gnome 160 HP engines. They did not have a fuel metering valve to change fuel flow, but did have a fine adjustment to regulate air flow.

The LeRone and Clerget engines, on the other hand, did have carbs and fuel metering (along with a fine adjustment lever, which is why there are two sticks on the throttles for those engines). Those engines could be throttled from approximately 700 to 1,300 RPM.

My research shows that the Oberursel rotaries were initially license-built Gnome engines (before the war), but they started manufacturing copies of LeRhone engines during the war. So, wartime Oberursel engines would have had throttles and an RPM adjustment range just like the LeRhone engines.

A ton of great information is available in the book, The Rotary Aero Engine by Andrew Nahum (1987). A good part of it is available from Google Books here.

There are also a ton of good threads on this board on rotary engines, like this one: Oberursel rotaries

Finally, sometime next year, an article of mine on rotary engines is slated to be published in a major aviation magazine. It deals with the myths and misconceptions surrounding rotary engines. I'll let everyone know when it is published.

Regards,

[D.A.]

Looking forward to your article Drew.

Thanks.

[Lufbery]

Originally Posted by D.A.

Looking forward to your article Drew.

Thanks.

Me too -- I don't get paid until it gets published!

Regards,

[Machinbird]

D.A.
Did you see the link to Franzkait's Oberursel engine build I posted in the Substitute engine thread? Here it is again.New Oberursel Ur2
Unfortunately some of the pictures have been "recycled".
Sid