BMW motorcycle engines on eBay.. Help!

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Chlomo

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Oct 8, 2014
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Seoul
Hi everyone!
It's my very first post and I'm really looking forward to learning from you all!:ban:

So I'll get right to the point.
From what I've read on this forum and some other websites as well I've come to the conclusion that using BMW motorcycle engines on airplanes is a very possible alternative to Rotaxs(with varying degrees of success). And yes, some look very very promising to a shallow-pocketed 20-year-old tinkerer such as myself!

So.. I buy a used motor on eBay..... And then what?:ermm:

A typical listing on eBay looks like this:


Now this is precisely where the problem starts for me. One can easily assume the vast majority of such sales come only with the engine itself without all the ancilliaries needed to actually run the engine.
Buying a whole bike complete with all the tiny nits and bits would be ideal but those are waaay to expensive.
At this stage I'm not even looking at things like PSRU(figure it out later), centrifugal clutch or destructive harmonics.

Simply put: How can I get the above motor running without buying a complete motorcycle? Any input would be greatly appreciated.

p.s Please excuse my English it's not my mother language.;)
 

Topaz

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Welcome!

Ah, you've run into the problem with these conversions (or any engine conversion, for that matter). Unless there is a manufacturer out there explicitly supporting the conversion of the engine to aircraft use, and providing a kit or at least plans, it's all up to you. All of it.

My understanding is that there are some companies in Europe who are providing BMW engine conversion kits (or possibly complete motors), and I'm sure one of our members from there will chime in with a link. Otherwise, there really isn't any "instruction book". You have to more or less figure it out yourself.

Another option for you, beyond the Rotax engines, might be a half-VW. Hummel Engines seems to be a popular choice.

And your English is completely fine. Better than some native speakers, actually.
 

kent Ashton

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I would look for a wrecked bike. Do they ride bmws in Korea? Here in the U.S. We have companies that auction them for the insurance companies. It will probably be cheaper than buying carbs, ECUs, starters, etc., off of ebay to complete the engine.

however, i think you'd save a lot of money to start with a small car 3-cylinder motor and construct your own belt reduction drive for it. A redrive for a bmw is going to be expensive.
Straight-three engine - Wikipedia, the free encyclopedia
 

JamesG

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Wait until you get a quote for the shipping charges! :shock:

In a project like this you really need to know what you are doing (no offense). You need to be familiar with the engine, all of its components, and how they work. Even if you got a complete donor vehicle. There are lots of gotcha's on how and where you mount those components in the aircraft.

Basically you can think of buying the "engine" as a down payment. Next will come all of the other systems and bits and pieces. Induction (carbs, EFI), ignition (plugs, capacitors, ignition control modules, most of the electrical system), exhaust (pipes, at least headers). While HBA can provide help on bolting it to an airframe, for specific questions about your selected motor, you might be better off finding the similar forum that caters for that particular vehicle model. There you will find people who are familiar with working on and know the above knowledge.

Best of luck! and welcome the nut house!
 

Vigilant1

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Chlomo,
Welcome to the forum. There is a company in Germany (Take-Off Gmbh) that sells complete assemblies (BMW-based engine, PSRU, ignition, fuel injection--everything) ready to bolt into an airplane--for about $12K. They also sell some components. There are far cheaper ways to do this, but even if you follow a path blazed by someone else (Kuba, etc), you'll still be doing a lot of work to find and fit the many parts you'd need.

Lets back up a bit: What type of airplane are you thinking about building? What will the authorities in Korea allow? Once we determine the size of engine your application requires, other possibilities may present themselves.

Again, welcome. I spent a year at Camp Yongsan right there in your home town. It's a beautiful country and I learned a lot.
 

Chlomo

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Seoul
Chlomo,
Welcome to the forum. There is a company in Germany (Take-Off Gmbh) that sells complete assemblies (BMW-based engine, PSRU, ignition, fuel injection--everything) ready to bolt into an airplane--for about $12K. They also sell some components. There are far cheaper ways to do this, but even if you follow a path blazed by someone else (Kuba, etc), you'll still be doing a lot of work to find and fit the many parts you'd need.

Lets back up a bit: What type of airplane are you thinking about building? What will the authorities in Korea allow? Once we determine the size of engine your application requires, other possibilities may present themselves.


Again, welcome. I spent a year at Camp Yongsan right there in your home town. It's a beautiful country and I learned a lot.

Hi sir! Thank you for your service!
And yes general aviation is still in it's infancy here in korea. Homebuilt Aviation? most people have never even heard of it.

I'm thinking about building a small single seater broadly comparable to the coveted Onex(roughly same dimensions except for maybe a narrower cockpit)!
It quickly became apparent there is no cheap easy bolt on powerplant! 12K is a little too much for me.

Thanks again
 

Chlomo

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Yes sir you are absolutely right! The shipping charges are prohibitive!
Maybe I should take a look at the more locally available engines. I really wanted to get one of those BMWs though.
 
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Chlomo

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Seoul
I would look for a wrecked bike. Do they ride bmws in Korea? Here in the U.S. We have companies that auction them for the insurance companies. It will probably be cheaper than buying carbs, ECUs, starters, etc., off of ebay to complete the engine.

however, i think you'd save a lot of money to start with a small car 3-cylinder motor and construct your own belt reduction drive for it. A redrive for a bmw is going to be expensive.
Straight-three engine - Wikipedia, the free encyclopedia
Thanks sir will definitely look into that!

And there are some used BMWs in Korea but more often than not those bikes are overpriced just because they are BMW.
 

Chlomo

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Joined
Oct 8, 2014
Messages
120
Location
Seoul
Welcome!

Ah, you've run into the problem with these conversions (or any engine conversion, for that matter). Unless there is a manufacturer out there explicitly supporting the conversion of the engine to aircraft use, and providing a kit or at least plans, it's all up to you. All of it.

My understanding is that there are some companies in Europe who are providing BMW engine conversion kits (or possibly complete motors), and I'm sure one of our members from there will chime in with a link. Otherwise, there really isn't any "instruction book". You have to more or less figure it out yourself.

Another option for you, beyond the Rotax engines, might be a half-VW. Hummel Engines seems to be a popular choice.

And your English is completely fine. Better than some native speakers, actually.
Thanks for your reply and kind words!

I've looked into VWs and half VWs and those seem certainly reliable enough. Sonex adaptation Aerovee costs some $7499 and a Hummel engine somewhat cheaper.. they never seem to approach $3000 mark!
My design calls for a cheap engine with moderate performance(50~80hp) without adding too much weight up front. It seems the 'not adding too much weight' part is a big obstacle.
 

Vigilant1

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If you are interested in a metal single seater, are on a budget, and like the Onex, perhaps consider the Thatcher CX4. It is designed to be built from plans, unlike the Onex. It is a little roomier than the Onex (which isn't important to you), and performs well on a 60 HP engine (it is designed for an 1835cc VW). Saving the cost of shipping a kit to Korea would save a lot of money, and most of the sheet metal and angle should be easy to obtain in/near Seoul. The wings aren't designed for rapid folding like those on a Onex, but they are easy to remove by one person and they can be folded back in about 15 minutes using a small fitting. Its not designed for or approved for acro, unlike the Onex.

Going with a 60 HP engine may open up more motorcycle engines and PSRU combinations for your consideration. And VW engines built from parts could be feasible: if you are content with a simple engine (hand start, no electrical system, etc) it can be done for about $4K with reliable components. Take a look at the catalog of Great Plains aircraft, it's a wealth of information, I think Steve Bennett at Great Plains will ship engines (he'll build it for you if you want) or parts internationally. The trick is to find a way to get cheap shipping as part of a larger container load of stuff.
 
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kent Ashton

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If you are interested in a metal single seater, are on a budget, and like the Onex, perhaps consider the Thatcher CX4.
The Thatcher is a great suggestion. Chlomo, before you go much further, you ought to talk to the S. Korean aviation authorities and see what can be allowed. I have a Japanese friend who is interested in homebuilt aircraft but he tells me it is virtually impossible to build a homebuilt in Japan and fly it there. You might find the same problems in S. Korea. He wants to keep a homebuilt in the U.S. but it is complicated for a foreign national. I hear Austrailia is pretty accommodating.
 

spaschke

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Denver, CO
Thanks for your reply and kind words!

My design calls for a cheap engine with moderate performance(50~80hp) without adding too much weight up front. It seems the 'not adding too much weight' part is a big obstacle.
I like the BMW engines and am
a BMW 1100R or 1200R may be too much horsepower for a design calling for 50 - 80hp. The weight may be similar to a 80hp vw, but the extra torque at full throttle could be a problem at take off or in a go around situation.
I would suggest looking into an HKS 700. It may be ideal for your design. I heard a new company is producing them now and am considering it for my Mini-max.
 

Chlomo

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Oct 8, 2014
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Seoul
I'm grateful for all the replys everyone! They helped me tidy up some thoughts.
It is my understanding that S.Korean regulating body does permit building homebuilts (at least to some extent) though I've read it can be tricky to pass all the checks and comply with strict regulations.
(sigh) Some situations seem just so insurmountable.
 
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