You do NOT have to have a -12F
Quote:
Originally Posted by
RRHaldeman
Hunter,
I recently completed the conversion of my 7AC Champ under the Lasher STC. I installed a C85-12F, added a Sky-Tech starter and an Odyssey battery, without a charging system. The C85-12F was modified by the O-200 conversion. I used an A&P, IA to work with me. You will need to use a C85-12F if you want the starter for several reasons: it accepts the starter on back of the engine and you don't need to modify the firewall. It is good that you have the enlarged dorsal fin and modified firewall (with additional supports) because they are called for in the Lasher STC. You can see a few pictures of my project here:
http://s900.photobucket.com/albums/ac207/RRHaldeman/
Mr Hunter has shown a -12F. The taper shaft and 'F' flanged shaft are interchangeable at overhaul and I believe either will work just fine. I have done some 65 to 85 conversions over the years. The biggest issues of firewall clearance, without going to the 'long' engine mount MAY be solvable with the new lightweight starters and alternators... With the 'long' engine mount we came very close to fwd CG unless we moved the battery to a spot inaccessably aft. One of the solutions was to use a wood prop. That took about 15# off the nose. As pointed out above you can do this as a MINOR ALTERATION (NO STC/337) if you follow the factories service letter.
AND PLEASE.. GET WITH YOUR IA BEFORE you start the conversion! B-))