The Cessna 120-140 Association Forum

I would like to talk to someone, anyone who has gone through the process of converting a 120/140 from the C-85 to the O-200. We are pondering this for our 140 "Marvin".
Please call me at 651-470-9647 if you would be interested in sharing the good, the bad and the ugly of the conversion.
Marc
Inver Grove Heights, MN

Suggest you contact Randy Thompson to answer your questions. He posts regularly on the site.

Randy Thompson A&P IA Pilot
Hold STC SA547EA for installation of O-200 engine in Cessna 120/140 and 140A"s
Overhaul small Continentals

8186 wrote: ↑Sun Mar 03, 2019 7:17 pm I would like to talk to someone, anyone who has gone through the process of converting a 120/140 from the C-85 to the O-200. We are pondering this for our 140 "Marvin".
Please call me at 651-470-9647 if you would be interested in sharing the good, the bad and the ugly of the conversion.
Marc
Inver Grove Heights, MN

Marc,

I just saw your post, have you gotten any responses? If not I've been involved in a couple mods. My own aircraft is one. Pretty painless really, the two engines are so similar it's almost a no brainer.

I have read that the C120 conversion to 0200 requires the engine frame/mount from the C-90-14 engine with Lord mounting system, as fitted C140a.

What would be the effect of fitting an 0200 to the original C-85-12 engine mount?

The engine would be about 3/4" farther forward and the cowl wouldn't fit right. CG shifts forward. There used to be an STC that allowed this, and added an extension to the back of the cowl. Don't know if it's still active. The name "Emmett" sticks in my mind. There are also adapters you can get so the O200 case accepts the conical mounts used on the -12 engines, but they're not approved and you'd need a field approval.