Upgrade 0-235 PA-12 to 0-290D2 Engine mount

[hoggboy]

I`m going to upgrade my PA-12 from a 0-235 to a 0-290D2 I have found the STC from univair (SA-202EA )
Which is another engine mount. Also found SA1-373 for PA-12 issued 11-13-58 from Copper river Airmotive of Alaska. As follows...
Description of Type Design Change:Installation of a Lycoming 0-290-D 125hp, or 0-290-D2 135hp engine, Sensenich M-74DM propeller, PA-18 engine baffles and Harrison #AP13SJ03-01 oil cooler in accordance with Aero-Marine Lycoming "125" and "135" installation in Piper PA-12 Manual dated August 12, 1959. The manual contains instruction sheets 1, 2, 102A, 201A, 204A, 205A, 206A, and drawings 102, 201, 204, 205, and 206. The engine mount must be reinforced in accordance with drawing 102 and installation sheet 102A for use with the 0-290-D2 135hp engine. For seaplane, use Edo 89-2000 floats, water rudder and seaplane fin in accordance with Item 204 or aircraft specification A-780

Has anybody ever purchased ( SA1-373 ) or have any ideal what reinforcements need to be done on engine mount, and if so, can it be done on the aircraft without taking the engine off. Having a hard time getting in touch with Copper river, they must be out flying. any help with be very much appreciated. Or Any other options.

 

[JimC]

On the mod of the 12 mount for 150 hp, it just amounts to splitting larger tubes, nesting them over the existing tubes, and welding them in place.

 

[algonquin]

I would be careful about welding the mount while it is wt. loaded. The mounts torque a little when installing. I'm not an engineer and really don't know the effects and I'm only guessing, so take this with a bag of salt not just a grain. Tom