|
A bulkhead mount was designed and constructed to enable mounting the MZ 34 upside down and using the original FireFly cage engine mount locations. Due to less engine mass and displacement, I expect the firing impulse that will have to be absorbed by the bulkhead and Lord mounts will be greater for the MZ 34 than the Victor 1+. If that is not so, FireFly empty weight can be reduced by replacing the Lord mounts with alumuninum spacers and plates.
Aluminum "L" extrusions were used to attach to the engine and to the rear cage engine Lord mount locations. To support gravitational and forward thrust forces to the front engine mount locations, a "V" truss was run to the top and bottom mount mid points. To keep the Lord mounts from spreading, tension members were added. |
First fitting of the engine and the new mount on the FireFly. It looks like the CG will move toward the rear, but the engine change will remove 40+ pounds. To compensate, the muffler will be mounted toward the front and the battery moved forward on the root tube.
The design goal was to minimize the engine drag profile while competely exposing the engine. This lets one use the maximum engine drag value in 103-7 calculations, while minimizing the actual effects. |