The BMW Huntwing coming to a field near you soon.
Utilising the BMW R100RS 2 cylinder twin valve 4 stroke engine and a Rotax C type gearbox 3.47:1.
Numerous problems have been overcome (I hope) including known problems with the Bing carburettors overflowing and the incredible weight of many of the standard components.
Following successful load tests etc. a permit to test was issued in January 99. To cut a very long story short and following nearly 70 hrs of testing the BMW Huntwing is now fully legal. To crown the story I flew it to Blois and back, 2 up, at the beginning of September. It is very smooth and quiet but the cooling is still a slight problem. If anyone has a set of moulds for cooling ducts they would be very much appreciated. At the moment the engine is cooled using a set of Mini plastic ducts but this will be improved.
It isn't be the lightest 4 stroke application but should be a cheap alternative to the commercial products currently available.
Fuel consumption is pretty reasonable but I will only be able to weaken the mixture once the CHTs have been brought down a bit more. On the trip to Blois we averaged 12 litres and hour which was identical to the 503 Huntwing that came with us single seat. There is also the advantage of using no oil. The engine also seemed to suffer no reaction to Avgas which is not something I could say for the Rotax 2 strokes.
Latest improvements, I hope, are a pair of glass fibre cooling cowls which can be seen in the new pictures at the bottom of this page.
More Pictures, select one and click to expand.
New pictures of the re-engineered Trike.
Front view of Glass fibre cowls Rear view of cowls The instrument panel Exhaust system
For all your BMW bits and good advice try www.motobins.co.uk and ask for Steve