My BMW R1150 conversions

[fly_tornado]

[mnewbery]

Try putting a drifter motor in a CBX. That would be something interesting

 

 

[Oscar]

my favourite bike was my big white/blue Honda CBX - six cylinders across the frame, fed by 6 tiny carbs. nobody could tune it until I met a motorcycle mechanic who had 4 of them and was a genius - first ride after he tuned the big beasty and I found out what those six cylinders could really do....and the sound...omg, six into two exhaust system and it howled like a banshee all the way to top revs...God I miss that bike - sniff, sob...at 100km/h you could drop it back to third, crack the throttle - and hang on tight or else!not sure, but I think I might have a few problems fitting a CBX motor to my Drifter...wouldn't go any faster but crikey it would sound good!

BP

The Blue/white scheme was on the second iteration; I used to ride the first one, in silver. Being a 65kg, 5'7" guy with a touch of Duck's Disease, with the flat seat and hugely wide tank with no grip pads, I had to roll off for each downchange, grab the grips again with both hands, and then open it out to WOT, otherwise ended up with rubber arms... but yep, did it howl! A rubber-band stretched to the horizon, really tightly.. It's acceleration saved my life twice on the one ride: the first time, when taking off across a wide intersection and some noddy in a spam-can ran the red from the other direction REALLY badly, and I managed to get across his bows with maybe a metre to spare; then later, when it tucked the front end and tried to smear me all over the southern half of the ACT and only every bit of power held it up.

 

Those stainless discs were nothing more than a vague indication of a desire in the wet, however. It was a fabulous tourer but not something for the twisties. For real riding, give me my first-model Viffer 750 - and when it changes from pulse to shriek (at about 5,500), it'll raise the hairs on the back of the neck pretty well.

 

 

[boleropilot]

hey Oscar, they were unbelievable machines for sure - believe it or not, when riding in the wet in traffic I used to keep a tiny little pressure on the brake lever to keep the discs dry and warm - so that they would work straight away, without having to wait a couple of seconds for something to happen! yes, I went through some disc pads, but I worked in a m/c shop so that helped - and I'm still here!

 

not all that many years ago they were available from the states for not a lot of money, but lately the prices have moved too far north for my tired old wallet.....always loved those VFRs - so nice...

 

BP

 

 

[boleropilot]

here ya's go:

 

 

BP

 

 

[M61A1]

As a long time motorcyclist, I find some of these stories amazing. Essentially because no-one remembers just how bad most of these machines were, face it, they were bloody terrible, but at the time they were all we had.

 

 

[Oscar]

They weren't ALL bad... My first street bike was a Honda 400/4, huge fun. The Duc Darmah was quite reasonable, and the 900SS was quite a machine. Then there were the dead-set killers like the Kwacka Mach III...

 

 

[Vincik]

Don't know if anyone is still interested in the original question; my Apollo DeltaJet 2 with BMW 1200 GS engine, TakeOff reduction and Trijekt engine management /electronic injection has of course different characteristics from a Rotax 912/ 4 cylinder, or the 914, but is a jewel to fly with low vibration and low consumption (8-10 ltr/hr at 90-100 km/h). Propellor kicks in from 2000 revs. Downside (?): it only has one magneto, but so far that does the job. Can recommend the combination even if the total weight is on the higher side. Needs a good, around, airflow (oil and air cooled, with oil radiator, no water), like all engines.

 

 

[mnewbery]

The R1150 engines from 2004 were twin spark heads so it's possible to convert to separate ignition with one fixed timing and the other from the engine computer.

 

As with all of these conversions, this (R1150 oil cooled) engine wasn't planned as an aviation engine so it's a dimishing return to take a land engine which started off cheap and easily available then change it.

 

Sounds like a choice between single ignition or a lot of customisation is required

 

*cough* Corvair engine instead of an O-300

 

*cough cough* turbocharged Volvo 166 engine in a glider tow plane

 

 

[fly_tornado]

Coil on plug is a separate ignition for each spark plug, you could wire in a switch for each plug if you wanted too.

 

 

[facthunter]

There aren't many auto engines or bike engines I'd put in a plane. Too much adaptation and mucking around. It's not that hard to build a simple engine from scratch if you have time and enthusiasm The amount of effort expended on VW engines you would have been better to start from scratch. There's been a lot of failures at making aero powerplants. I don't like flat fours.particularly. They fit in the cowl well, but that's all. Nev

 

 

[fly_tornado]

All the Rotax engines are derived from snowmobiles, BMWs are popular in the EU with microlights because they are a well built engine. Several OEMs offer microlights with Take Off's FWF kits

 

 

[facthunter]

I'm not sure they are a good conversion. They're a pretty lumpy engine. Just being well made doesn't mean everything. Horizontal motors in 2 and 4 cylinders have the most fluctuating piston- flywheel effects. That's hard on a drive. Nev

 

 

[mnewbery]

All the Rotax engines are derived from snowmobile..

Says who?

 

 

[fly_tornado]

Matty:hide:

 

 

[mnewbery]

I'm going to take a big breath, write this post and ignore the thread.

 

I have had significant experience towing a loaded trailer behind a R1100 engine and I have seen what RPM develops harmonics and how the whole system behaves across a wide range of speeds, loads and throttle settings.

 

Is this information directly transferable to an aero engine experience? In my opinion, no.

 

Is this information directly transferable to other opposed twins and in particular the R1150? In my opinion, no.

 

Did Wikipedia note that the Rotax 582 was based on the Rotax 532 which was a first design aero engine from the 1980s and not based on a snowmobile? Yes (and it took me three minutes to find)

 

Have thousands of Rotax aero engines (582 and 912) been run to TBO and/or destruction? Yes. According to Wikipedia Rotax celebrated 50,000 912s in 2014

 

Are the common failure modes of Rotax aero engine and gearbox systems (582 and 912) well documented? Yes (the civil aviation authorities saw to that)

 

Has BMW produced tens of thousands of R1150 engines and reported on what went wrong in normal road use? Not in any official capacity that I can find

 

From Post #108 above, I am very interested to hear of the experience of Vincik and specifically how many hours did the engine have in road use plus how many hours aloft before it gets/got pulled out for overhaul, what is going to be replaced and how that was decided (e.g. were the counter weights on the crank no longer parallel). I also wish Vincik the best and safest experience with it. I encourage M61A1 to join me in saying that I hope this is a proven long-term good combination for Vincik after his (M61A1) experience with the Moto Guzzi V50 Monza and Venner V-Twins in top of the Rotax 582.

 

My points:

 

The Rotax gearbox is a known thing but attaching it to something other than a Rotax engine is an experiment which each pilot will personally conduct every time they decide to thumb the starter.

 

I know I won't have to worry about a BMW powered anything doing an engine out landing near my house.

 

I don't think a "BMW caused engine out landing" will be an issue in Toowoomba because if my suspicions are correct the OP isn't a pilot and the OPs engine will never be run to the point where it is worn out.

 

He/she doesn't provide checkable references for comments about Rotax or BMW so I can't apportion the probability of truth in his/her favour for any other comments in this thread.

 

Do your own research and take responsibility for your conclusions. I don't have an issue with the R1150 conversion and I encourage people to take calculated risks in support of everyone learning and sharing more about information about engine and gearbox combinations.

 

 

[fly_tornado]

matthew you need to take a holiday

 

 

[mnewbery]

fly_tornado and Gandalph Posts Moderated

[fly_tornado]

Matthew I clocked up 6 hours in the shed this weekend, about 4 productively working on my planes. How was your weekend?

 

 

[boleropilot]

I had a Kwaka 500 - mine was the H1-D, fourth version, so a pussycat compared to earlier versions, especially the H1-A, which was widely reported as a Widow Maker

 

my 'quietened down' D model was still a force to be reckoned with - two stories:

 

1. I was riding up a hill in light rain, 5th gear, accelerating, the tacho reached 5,800 rpm and I got wheelspin - in 5th gear...

 

2. A colleague asked me for a ride - I agreed, told him to be careful - he came back and said it was a pussy - I asked him if he had gone over 5,000 rpm - he replied that he didn't want to thrash it on me - I told him to go for another ride, and this time take it to the redline, but not in a lower gear - he came back as white as a sheet, shaking - he said that he got to just under 6,000 rpm in third and the front wheel came off the ground so fast he thought he was going to flip it...

 

as for the CBX - just wow, a real Rolls Royce of motorcycles, crack the throttle at 100 km/h in third gear and you'd better be hanging on......

 

BP

 

 

[Old Koreelah]

Similar story for me, BP. I rode my mate's Mac III to see what all the fuss was about. What a fizzer- gutless!

 

I'd been riding it like I rode my 4-stroke twin. I was sent back out and told to wind it out.

 

At 5,500 rpm I got the shock of my life. Thought I'd been hit from behind by a truck!

 

That sledgehammer acceleration came at a price- all our trips had to include frequent refills. The best fuel economy he ever got was 24mpg.

 

 

[kgwilson]

I bought a brand new Mach III H1 in 1971, the blue (widow maker) model. Ginger Molloy came 2nd in the 1970 500cc World Champs on a H1R & he opened a bike shop in Hamilton NZ & I bought it there. The power band was from 4500 rpm to 6500 rpm and it was lethal. I wore out the first chain and rear sprocket in just on 5000 km. A new Reynolds chain fixed the problem with the original "elastic" chain. The frame was somewhat elastic too but once the faults were mastered I was pretty much unbeatable. I used to love coming up behind traffic doing about 90 kmh drop down a couple of cogs into the power band & tear past the line of traffic on the back wheel. The fuel consumption was awful when pulling stunts like that as was the amount of 2 stroke oil used. The amount of smoke would not be allowed today. On a trip cruising at around 100 to 110 fuel consumption was quite acceptable though at around 30-35 mpg. The brakes were something to behold. A big drum up front that worked really well....once. Then it faded into nothing & that was scary.

 

My flatmate had a 71 Norton Commando & when we swapped bikes he could not keep up with me. The Commando handled like a dream & the Kwacka scared the crap out of my flatmate.

 

 

[boleropilot]

hey kg, I worked in a motorcycle shop in the H1 days and we used to sell all sorts of stuff to get these things to handle - the standard swingarm was a couple of lengths of mild steel 1" tubing welded into a U shape - we sold a LOT of aftermarket swingarms made up from aluminium rectangular tubing, about 2" x 1", man that made a difference - the fact the system came with German made roller swingarm bearings was top notch engineering in those days - we sold a lot of these along with 'racing' shock absorbers too, all set up as a package deal including modified front forks (springs, oil, etc.)

 

I remember one guy seeing a bike undergoing "the transformation" and he asked the owner if he was going racing - the owner just said "Nah, I just want to live, that's all"......says it all !

 

mind you, we were selling hot up gear to the loonys too - three into one tuned pipes, bigger (or re-jetted) carbs - crazy coots...

 

BP

 

 

[fly_tornado]

back in the days when 60HP seemed like a lot

 

 

[facthunter]

Those 3 cylinder piston ported Kwacka's were fuel cooled. About the same fuel consumption as a Chevvy car. Power comes on with a rush just to make things interesting. if you are doing a "U" ey on a wet road . Worked on them but never wanted to own one. thanks. Nev.