Prop Spinner Backing Plate

[TomVal]

I recently updated from an older Jabiru 2200 to a new generation 4 engine. In anticipation of installing the new engine I also ordered a new Sensenich wood prop at the same time drilled for AN5 bolts based on a prop flange bolt pattern diameter of 4".

Well, today was my long awaited engine start day only to discover my prop does not fit the prop flange on the new engine! The old engine had an AN5 prop bolt flange diameter pattern at 4". The new engine uses a bolt diameter pattern of 4.5" for AN5 bolts and 4" for AN4 bolts. There was no mention of this dimensional change in any Jabiru literature so I was blindsided by this.

Fortunately, Sensenich drilled my new prop for AN4's on a 4" diameter. Maybe I can get away with just a new aft prop spinner bulkhead drilled for AN4's.

Does anyone have a source for these backing plates? I need an 11" diameter spinner backing plate with holes for the bushings and AN4 bolts drilled on a 4" diameter pattern. Sensenich does not sell hardware for wood props.

[TomVal]

I guess I'll answer my own question. Here is a company that manufactures matched and balanced spinner and backplate combinations for experimental aircraft.

https://www.cumminspinners.com