Just found a Stinson 108-3 that the owner is selling because he got too old to finish the project. He sold off the old 165hp engine and bought a 220hp mid-time Franklin engine and propeller to go with the project. He said I'll need a new engine mount to bolt the 220 to the airframe and a different exhaust system and a bigger oil cooler. I just want to make sure I know what's involved and that I can get this done without major obstacles or too much expense. Does anybody have the parts needed or part numbers list to bolt in the 220? Has anybody had experience swapping out the engine in the Stinson to the 220hp and some advice to give? Thanks

Assuming you are in the US, and this is a certified (non Experimental) installation, you'll need an STC (an example shown below) which will contain the information and authorization you seek.

http://www.franklinengines.com/stinson.cfm

You'll also need an A&P to oversee the work, and sign off on the completed effort.

Join the Franklin engines group on FB if you're on there, and contact John Askeland. He's the STC holder, and seems to be getting involved with helping people do conversions again. His website is http://www.franklinengines.com.

Find out what fuel pump the 220 has on it- the diaphragm style has been grounded by AD (my understanding, anyway), and the Weldon replacement seems to have poor support from Weldon (at least as far as purchasing new). However, I've found a source of "as removed" Weldon's and plan to buy one for myself and a couple of friends that have 220's.

Thanks - I'm in the U.S. and keeping it certified. Learning more about STC's and what's involved in the conversion. I talked to a pilot & IA that got the STC and parts from Franklin Aircraft Engines in Colorado and said it was high quality parts - everything fit like a glove, and installation was real easy in his Stinson 108.

Thanks Kelly - I got in touch with the STC guys in Colorado and the Stinson with the 220 horsepower Franklin does not use any fuel pumps - No electric boost pump and no engine driven fuel pump. Looks like a nice and simple installation and well worth it. I was wondering how much a Stinson with the 220 is worth? I saw a 170B for sale on Barnstormers with the 220 and it was priced at 90K!

I am going to start my 220 next week on a -3. John is excellent to work with. You are correct there is no fuel pump all gravity. The FAA has a stance that anytime the HP change is more than 10% you must now have an stc. It is great the John has started to support this again. I know of 3 going together now, one with a turbo 220.