The Engine
We decided to install a BMW R1200GS engine, like the motor above. It is a 110 hp engine, after reduction
104 hp left. To complete this part of our project we have to work at separate locations. My dad has started with
the final body work. I am working, at my own home, at the fwd fire wall.
I borrowed a jig that support the engine in the engine mount proces. Thanks to Jan H, builder of a Cherry bx2
aircraft.
This is the gearbox, We choose a 2.8 reduction. I think this will be the correct match of the KR-2S. The
Cherry bx2 is flying with the 110 hp engine and is using the 3.2 reduction. The Cherry can handle a 64 inch
propellor. Our KR-2S can handle (after a test session) only a max off 62 inch. But the KR-2S is a bit quicker
and lighter than the Cherry. This 3 facts brought us to the 2.8 gearbox. If this is not working, we can change it
at the gearbox company Take-off.
After a lot of calculation off the weight and balance, we alined the jig with the engine at the calculated distance
to the fire wall.
Starting with the engine mount.
Because the diagonal members are welded on a cross welding we have to final weld the upper section.
I did the tack welding myself and left the finishing job over at a professional welder. Jacques P. did a great job!
Diagonal members installed.
Made a jig for the welding.
After welding the mount, we made a final fit in the original firewall. You see at the front 3 attachment point
steel plates. These plate’s, with some washers, will simulate the shock mounts to prevent vibrations to the airframe.
The muffler
We bought U formed 1.2 and 1.0 mm tubings and flex joints. I did all the welding myself. I am happy with
the result.
We tried to make a muffler like the original situation for the engine. At first the catalysator, than the
original muffler from the BMW 1200. In the Netherlands there is for airplanes a sound category. That is also the
reason to make a good muffler......pitty, because it cost you a lot of weight. 6kg
System needs final grinding and some polishing.
Made a dolly where I can build the complete fwd firewall. If you remove the stupid feet and
replace the wheels it will fit in my car hahaha
After the test run and everything is satisfied, we did a heattreadment to the engine frame.
Sprayed
And installed to the site wall. We used fibrefrax between the metal sheet and the wood.
Alternative crane.
Happy that our KR-2S meets his friend BMW. All wiring was already finished at the location where we build the firewall FWD
Overvieuw pic
Back to home