I am itching to tinker with a E85 conversion. I have a few old engines in the drawer : 46, 52, 60, 120 I'd like to try one of these out. OK I understand it is probably not worth the cost in terms of fuel savings etc. (46-60 engines are not that fuel hungry and I don't fly that often).

From another thread on this forum, it appears that E85 conversion is straightforward. I don't need a new carb. All I need is an ignition module and magnet. The fuel oil ratio stays the same. I can use Castor in the fuel oil mix.

I'd like to know the smallest reasonable size that one should attempt to do these things in order to have a chance of success. How much weight would the ignition module and battery add? I plan to put it on an Eindeker so plenty of wing area.

Thanks for you insights.