The Cessna 120-140 Association Forum

Hey all,
I own a very nice 1948 C-140 an man do I love it. I got my tailwheel in the airplane and later found it for sale and managed to get my hands on it. It's got just about every upgrade I would want to do to it: VGs, Lightweight Batter, Lighter Starter, Climb Prop, Baby Bushwheel Tailwheel, Tailwheel Shimmy Dampener, Nice radio, etc. The only thing it's lacking in my mind is power. I know that's a bit of a dull point when it comes to a 140, not exactly the most powerful or capable aircraft out there. She's currently got a good ol C-85 in her, but a little more power would be a wonder.

I currently am located in the great state of North Dakota, and density altitude and temperature aren't exactly a concern. She climbs and flies just perfectly year-round. However, the plane and I will soon be returning to the slightly higher state of Colorado. In my experience flying it out there, the plane is very much a start at sunrise and be done by noon, no matter what kind of aircraft.

I've always wanted to get into more backcountry esc flying, so the real question here is: is it worth doing the upgrades on the 140 to turn it into something that maybe it could be? Or am I better off jumping up to something like a 170B that I know I can make into something that can do well in the mountains and backcountry?

I've already got quotes for the work to convert the 140 to a C-85 stroker, I just don't know if it is the best option out there for it for what I want it to do. Or am I trying to turn a pigeon into an eagle?

Did the conversion back in 2013. It’s nice but not a game changer.
I have a standard prop on it and the conversion turns it into a climb prop. I have to watch my RPM in cruse. I don’t know how well a climb prop would work with it.
It took almost a year to get my plane back in the air. When I flew it again I didn’t notice much of a difference except the RPM in cruse.

I wouldn't do it unless I had a C85 that needed a crank. Disclaimer: I have a C90, which already has that crank...

I was an aviation journalist writing for one of the well-known aviation magazines for many years and I got to fly a LOT of backcountry airplanes. From Huskies to Super Cubs to souped-up 140s and many, many more. I also owned a Cessna 120 with the C-85 "stroker" mod and flew it around the West for several years. Today I have a Cessna 140 with a C90. I prefaced with all that to simply say: In my opinion you are trying to put a square peg into a round hole.

First, it sounds like you've got the backcountry "bug." In that situation- and as much as you wish it- a Cessna 140 is never going to satisfy you. It's a great airplane that does everything decently and nothing wonderfully. It CAN fly into backcountry strips. It CAN land on dirt and grass. It CAN maybe carry a couple o' small bags and 2 small people. But it does none of those well. You will ALWAYS be wishing you had more power, more room, more payload, and better climb. A Stroker mod, all-in, is going to run you $30,000 installed these days. All that for a few more horsepower that you'll hardly notice (we noticed a TINY bit of improvement but nothing dramatic).

Again, in my opinion, if you really want to do the proper backcountry thing, be safe, fly with a good safety margin, and have the capability available that you will eventually need and want, stick with the RIGHT tool. And the right tool is a Husky, Supercub (and all the "cub" variations), Cessna 170 with an IO-360, a Katmai 182 (that one will blow your mind), a Bearhawk, a Cessna 180, etc. The 140 is wonderful. But trying to crow-bar it into a great backcountry airplane is like trying to get your ugly girlfriend on the cover of Sports Illustrated.

Have a 120 with a stroker and have flown 120/140s with C-85 and O-200. I think the stroker is the sweet spot as it seems to provide more torque and will, as others have noted, make the standard 48" pitch prop behave more like a 46" climb prop. So you need to take a fist full of throttle out as you level off. Since OP already has a climb prop, it may not be of great value.

Almost always fly solo, but most flights start with full fuel, and will see 450 fpm at sea level at 105 F and more like 650 fpm at 2000' MSL and 60 F.

Very comfortable with 1200-1300' strips without observations and 1600' with trees is also doable. So it's not an aircraft for the 700' strips (Super Cub does those) but will handle fairly short almost bush strips. YMMV.

I've talked with many owners who did the C-85 stroker. They like it and can notice the improvement. It takes "most of the stress" out of flying with two people out of grass strips in the midwest. How well it will do out west...........I'll leave that to others.

I will say I never heard an owner say "it wasn't worth it".

I appreciate all the replies. After some consideration, I dont think I am going to go ahead with the conversion as of yet. Ive still got some good time till TBO on my engine, and its not quite worth the 15-20k that I could potentially be dropping on an engine that doesnt need to be torn down just yet. It is still definitely a consideration for the future, however.

If anyone has any other ideas or suggestions, I'm always all ears!

Thanks!

I agree, that's a lot of money (and down time) to tear apart a perfectly good engine for a very small improvement in HP. Also, with the price of C90-0200 cranks nowadays (if you can find one), that alone would make it a hard "no" for me.
Josh