BMW R1200 motorcycle engine

Sweet engine,

Is that pounds or kilos on the scale? I'm guessing kilos..?

Hi. Yes, 74kg (163 lbs)
And I agree - it is a stunning engine. I have been aware of the BMW boxer engine for ages, but had read (repeatedly) that they were too heavy. Well, 74kg complete with redrive, starter, alternator and all the other bits is definitely heavier than a Rotax 912 - but then again, almost all engines are. The BMW is certainly no heavyweight. And at 100hp, it is almost 25% better hp/weight than the ubiquitous VW conversions.

And best of all, it is the ideal engine for builders just like me - who know next to nothing about engines. We just want a simple engine we can transfer to our aircraft and go flying behind.

I don't know why it has taken me so long to find this gem.

Duncan
PS Perhaps best of ALL, is the fact that I can go out and buy a very good used R1200 motorcycle on a normal finance deal, and pay it off over three or four years. Try doing THAT with an aircraft engine.

It looks like an attractive package - but do the numbers - i think you will find its heavy , the drive , bellhousing mount , engine mounts cost more than the $1500 . And from what i have heard its a shaker . Also the cooling is incorrect if you want a tractor ( the exhausts face back ) . I am under no delusions about the Jabiru motor - it needs work , but you can end up with something which weighs say 60 Kg , has the mounts in the right place and is fairly straightforward . I like you like the idea about the BMW engine but i have never seen one flying in OZ , but i have seen some of the failed attempts . I even tried to compare the 3 and 4 cylinder Suzuki , but it too needs work , is heavy and the drive and bellhousing cost almost $2500 before you start . Europa tried the BMW and gave up and it has just has not seemed to make headway . I wish there was a more reasonable alternative. The Rotax is the price of a reasonable car so that does not make sense either !
Flyoz

Have you considered the Geo/Suzuki engine?
Raven Rotorcraft & Redrives : Geo-Suzuki Engine Conversion for Gyroplanes Autogyros Ultralights
Air Trikes: Engines and Conversion Kits.

Kevin

Hi,
The Suzuki engines are great, and yes, I have been considering them for some time now. However, they are not plug and play engines, like the BMW is. The only Suzuki engine producing close to 100hp is the G13, and because of its configuration, this engine has to be mounted sideways, otherwise it is way too high to fit under the cowling. And this doesn't appeal to me. And then there is the matter of cost, of course. The BMW is still way cheaper.

Actually, I have a 4-cylinder K10A engine in my workshop (100hp, 4 cyl, EFI, turbo) GREAT little engine. But to have it stripped, and rebuilt with the required forged pistons etc would cost as much as a low-mileage BMW anyway. So I'm going to sell it to offset the cost of the BM.

There have been some comments about the vibration of these engines at low RPM. I suspect this is more to do with torsional vibration than the engines being unbalanced, however. So I was particularly interested to read the other day about the re-drive of choice among the Europeans, who choose the BMW very frequently to power their aircraft.

"All satisfied BMW-flyers I know are customers of Wilfried Bleidiesel (www.takoff-ul.de). I recently purchased a clutch with a one piece disc from Wilfried. This clutch is proven, not as heavy as the other brands and it matches the endurance of the gear drive."

So off I went to takeoff-ul.de, ran it through altavista.com's on the fly language translator, and was able to glean sufficient information about their redrive and clutch combo to get me really interested. Basically the centrifugal clutch only engages at about 2500 RPM well past the RPM range during which torsional vibration is an issue. The drive is a bit pricy (2500 euro) but in the grand scheme of things, I think this a a great solution.

Duncan

Hi,
There is a major drawback with the R1200 engine. It runs completely on a proprietary ECU which expects a zillion inputs from such things as tyre pressure sensors and the like. Remove these sensors, and the central computer logs an error. Too many of these errors, and the computer throws a hissy fit. Not a good idea at 3000 ft.

The only way round this is to invest in an aftermarket ECU and program the thing yourself. This is not as daunting as it sounds, because modern ECU units are extremely capable. The Link ECU unit (made here in New Zealand) has a network of dealers who are quite capable of mapping the engine for a nominal fee.

Sincce the R1200 S engine produces 122hp in standard trim, and dollops of torque, I'm keen to move on this engine. Far from being overweight, its weight (74kg or 163lbs) is very competitive with other engines of similar hp. And for the additional cost of about $1300 (NZD) or $650 (USD) the ECU problem goes away.

My aim is to buy a late model used motorcycle, so that I can get my hands on everything from air intake, ignition, fuel injection system, fuel pump, starter, exhaust etc. Then I'll sell the rest - including the computer + loom. I plan to use the stock exhaust as far as possible, only replacing the pipes which need to bend in different directions - keeping the same dimensions - ie the identical configuration.

This sounds like a very nice winter project. Next winter, of course. In the meantime, I need to get myself into my new hangar workshop, and continue with the fuselage construction.

Duncan

I went for the KISS principle i.e. Keep It Simple Stoopid. The BMW 100RS is a lot simpler and has none of all the extra bits which weigh and can go wrong. I don`t agree that aviation useage puts more stress on a motor like the BMW 100RS, imagine two heavyweights on a bike storming away from a standstill and urban traffic, up and down the box as opposed to a take off and reasonably constant revs in cruise. Peak revs approx. 6,500 but use prop to ensure cruise to coincide with peak torque not power. See www.hughlorimer.co.uk for photos of fitting and reuction gear. A cush drive is essential.

Hughie.

I know Kuba Mysluk well.
he have the BMW in his airplane, he also installed 20-30 of them in other plane, (before he put one in his) he also use the ECU that come with engine/bike

Jan

Jan,
thanks to show me this forum.

All,

If someone is interesting in flying BMW R-series, I probably can answer any question regarding this engine. I spend hundreds hrs behind it, mine personal plane have BMW1100S.
Real planes, real knowledge...

One issue for claryfication:
I'm kind of "specialist" regarding former 1100 and 1150 BMW engines. 1200 is a far different, I converted only one of them, and the result was quite bad. I talking about genuine wireing and genuine EFI conversion, I not using aftermarket EFI systems (as Silent Hektik for example)

regards for all homebuilders

Kuba

Hi Kuba,
I am still quite a long way from needing to install my engine, but I had thought that the R1200 was the way to go - mainly because of the lower weight, higher power and the balanced crank.

Could you tell us more about the sorts of problems you encountered with the R1200? I'm asking because the local engine shops here in New Zealand seem to think that configuring a Link ECU would be a relatively simple matter. Possibly the wiring might be a challenge. Is this one of your concerns? ASnd if it is, why would the wiring for an R1200 be much different from that of a R1100?

What is the weight and power output of the R1100S? If you are correct, I'm not going to argue - I want to be sensible about this, so any information you can provide would be welcome.

Cheers, and welcome to the forum.

Duncan

Hi,

The BMW R1200 is an excellent engine... but the mainly problem is BMW politics. They will not talk to You when Your immobiliser will broken, turning Your engine to piece of expensive junk. Maybe if You will have rest of bike, special plastic key, the special code label and VERY friendly serviceman in BMW station. The new immobiliser unit will be prepared in factory in Germany based on labels and keys, then it had to be logged into EFI computer. They NOT support BMWs used in other than vehicles! (or even in the BMW bike if You dont have all stuff I mentioned above)

The genuine wireing contains three computers;
EFI computer called BMS-K
Automatic fuse unit called ZFE
and ABS computer (builded into ABS mechanical unit)

It is possible to aeroconvert 1200 (If I did it - You can also), the main problem will be PSRU. I suggest Take-Of (Germany) or Polmotor (Poland), just buy&bolt. Regarding wireing... it is just impossible to do this without electrical diagrams for exatly Your version.
To determine it - the bike VIN code number is necessary.
Diagrams You probably can obtain from BMW service center. (or from me, at least).

If You want convert it, You must have few other elements also: as neutral gear sensor (it will not engage starter if missing), the bike key-lock and main bike display. This is modern engine controlled by CAN-bus and nothing is similar to the typical aircraft engine. Funny, but all lamps, starter and even horn is coming from ZFE unit.
Aerononversion is just carefully cut off the non necessary part of cables, simulate the neutral gear position sensor, and fit in single box the immobiliser antenna with the genuine bike key.

The power.. well, the power of 1200 is bigger than 1150, but still: if BMW advertized R1200S as 120hp, the torque stand show max. 110hp. same for other variants. Due to fact so we cant use genuine exhaust and airbox, the real results in plane will be even worse.

I preffer BMW 1150 RT, R, RS (or 1100S only), managed by simple Motronic 2.4 EFI.
Power at level 80-85hp, no stupid immobilisers logged into EFI, slightly heavier than 1200. Vell proven and much cheapper than 1200.
I just cant now write here about all my experiences with 1100 and 1150 learned last few years, its long story good for book, not post, but: the main problem of 1150 is vibration. the cure is heavy flywheel (3-7kg), very elastic engine mount and using of centrifugal clutch engaged 2200+ rpm. Last is very controversial and uncommon device, used for disengage the prop at the idle, (mainly when gliding on final).

OK, I hope all this can be interesting for someone, even it is very briefly. Course, I will answer detailed questions here.
If somebody is interesting in flying BMWs - let he subscribe Yahoo/moto-air group. I put many posts, mine (and others) installation photos are also availiable.

regards

Kuba

Kuba,
Hi. Thanks for your excellent reply. I will need to consider this carefully. I had intended to purchase an entire motorcycle, so all the bits you mention would be included. Still, some of your comments are sobering.

I'll check out the moto-air group on Yahoo also.

Chers,
Duncan

Hi Kuba,
Thanks also for your detailed post in the other BMW thread. Since this thread is the older of the two, perhaps we can confine BMW posts to this one? I'll see if we can get the other thread incorporated into this one.

Cheers,
Duncan
PS I'm at work at the moment, so I can't really spend the time on your post that it requires. I'll re-read it tonight, and get back to you with questions/comments.

Cheers,
Duncan

kuba..

Just wanna say Welcome! You willingness to come here and help is truly appreciated.

I just put in my album few photos of BMWs I work, just as example. Enjoy!

Kuba