M4-220 Franklin Overhaul Opinions

[JPROLLINS]

Alright guys I need some opinions.

Backgroud:
I purchased a 1970 M4-220 that was restored in 2008 and is really well done. The motor had 65 since being rebuilt; however, it sat for a couple of years before the airframe was completed. I put another 40 hours on it over the past 4 months. During annual this past week there was excessive metal in the oil. Opened her up and there is pitting in the lifters, cylinder walls scored, and uneven wear on the cam.

Today:
Engine will be off to Southern Aero to be split apart and assess the "fix" with the potential of a full overhaul. My question is what kind of things would you upgrade/change during this time? Im thinking, definitely go to direct drive on the alternator since he has two overhauls in the shop right now from them eating metal due to overtensioning the belt drive. Probably send the prop to the shop, since when I bought it the logs were a little sketchy as far as overhaul on it. Is the C201 prop swap something I should look into?

Thanks for any advice.

Jackson

[aero101]

Sounds to me like you're gonna need a full engine overhaul with your stated defects anyway? Some of the parts are getting hard to find, but I think the Southern Aero guys should be able to help out in that respect. If you should need a crank which are really scarce, give me a call as I have one that can be made serviceable I'm pretty sure... Good luck!!

[MauleMechanic]

The last two Franklins to come into Maule Flight where bad. Both crank issues, bad cams and cylinders. One was sent to a Franklin specialist, forget HER name, and the other is still here.

[vaughans]

Telephone: 903-626-5115 . 903-626-5210 • Fax: 903-626-6658 • Contact Susan Prall - FRANKLIN ENGINE COMPANY, LLC

vaughans

[MauleMechanic]

Telephone: 903-626-5115 . 903-626-5210 • Fax: 903-626-6658 • Contact Susan Prall - FRANKLIN ENGINE COMPANY, LLC

vaughans

Yeah, thats her

[JPROLLINS]

Thanks for the heads up guys. The Southern Aero guys are in my back yard so the engine is going to them. I havent heard anything but good about them. If we have any issues finding parts I will definitely refer back here.

Still looking for any recommendations on swaps to different parts.

Thanks

Jackson

[pilot]

I think the 220 Franklin is a fine engine and a fine (probably best ever) fit for a Maule. I have one that is approaching TBO and really look forward to flying it to that point. I can't say with any certainty that I will overhaul it, but I really like the engine the more I look into the overall picture. A lower compression 220 with electronic ignition would be, in my opinion, about as good as it gets.


I would prefer that someone in the USA tool up and start producing the Franklin and needed parts, dammit. I would rather have an engine that has available new parts and factory support - so I am not totally opposed to swapping over to an o540 or io540 if I had the opportunity. A 180 would be another choice, but who ever says "gee, I wish I had a bit less power"?

[rbowen]

Don't be too quick to euthanize an engine just because it gets to "TBO." the bottom end of most engines are very durable. I have a friend with 3800 hours on his engine. Cylinders are expendables and can be replaced as required.

The strategy should be to put the engine on oil analysis so you see the metals trend, borescope the barrels every 50-100 hours to check for any hot spots developing on exhaust valves, use a trend monitor for the engine, and fly it until you need to do more. Save your money for something else, like gasoline!

[captnkirk]

I spent a good deal of time talking with Bob from Southern Aero at sun n fun. He was hopeful that some of the harder to come by parts may become available thru some third parties (cranks and cams). Other than that he has a good supply of most everything else. While there is not the same level of support as with Lycoming and continental you should be able to keep those Franklins running

[aero101]

Sue Prall is also another GREAT source for parts, tooling, etc... She is a great resource, and has specialized in the Franklins as far back as I can remember... On another note, it is a great engine that is super smooth, light weight, and very economical on fuel, and no slouch when it comes to available power... I have heard rumors they may be going back into production again in eastern Europe, which would be nice....