Backcountry Pilot

[Soar07 offline]

I am looking at a 108-1 with the 165/178 hp high compression cylinder stc.

How would a Stinson fare in Colorado with that setup? It needs to be able to takeoff from Aspen or at least Glenwood Springs, and be able to get over the mountains without any issues.

Thanks in advance for any insights or recommendations.

My other aircraft of interest is a C-170. I need something easy to fly to teach my daughter to fly, and fun for mountain and camping getaways.

Thanks!

[pitman11 offline]

If you are looking at the one on Barnstormers I would check facts more they did not make a 108-2 in 1952, the high comp piston are just the helicopter ones, i'm not sure it can turn 150 hp to 178 hp with the stock f150 m3 carb, inlet manifold and exhausts. and it still has to run at lower rpm since its not the heavy case. I have been to vfr on top 10,000+ msl just fine with my stock 108 but in the morning and not fully loaded

[Tadpole offline]

If you are looking at the one on Barnstormers I would check facts more they did not make a 108-2 in 1952, the high comp piston are just the helicopter ones, i'm not sure it can turn 150 hp to 178 hp with the stock f150 m3 carb, inlet manifold and exhausts. and it still has to run at lower rpm since its not the heavy case. I have been to vfr on top 10,000+ msl just fine with my stock 108 but in the morning and not fully loaded

Ya that SN was a few off of mine, it's a 47. And the chopper pistons are not an STC either...it's like putting the 220 crank in the 165, nothing really allows it but folks do it.

[Soar07 offline]

Thanks a bunch for the replies. Yes, the FAA shows it as a 47 also. Seller confirmed it is a typo.
Also, title is currently cloudy, so he has to work through that also. So, back to research mode right now.

[OregonMaule offline]

more power, more power, more power

[Soar07 offline]

If I get the title issue cleared up would this plane be a better choice than a Cessna 170 for Colorado?

Also, the piston issue makes me wonder if it is a legal mod? Owner says he has an STC for it.

What about fuel with this mod? Will the higher compression negate autofuel as an option?

[OregonMaule offline]

If I get the title issue cleared up would this plane be a better choice than a Cessna 170 for Colorado?

Also, the piston issue makes me wonder if it is a legal mod? Owner says he has an STC for it.

What about fuel with this mod? Will the higher compression negate autofuel as an option?

High compression and mogas don't work.

Good day

[Tadpole offline]

If I get the title issue cleared up would this plane be a better choice than a Cessna 170 for Colorado?

Also, the piston issue makes me wonder if it is a legal mod? Owner says he has an STC for it.

What about fuel with this mod? Will the higher compression negate autofuel as an option?

Then his STC is a typo as well, there is no STC to upgrade the Franklin 150 or 165 with high compression pistons. If he has a 337 for it, I'd be surprised. There are several Stinsons in Colorado, two of them on this board with bigger engines. I know there's a few others with the Franklin 165. I owned one there but didn't get it flying before I moved. The Cessna 170 was on my list too when I lived there and to me the 170 and the Stinson with the Franklin 165 were pretty comparable. Buy the best one you can afford. You'll want more power, but either will do fine for you. Just stay light and fly early. Afternoons suck to fly there anyway regardless of horsepower due to turbulence and winds

[pitman11 offline]

Looking at the pics again I do not see the baggage compartment, that would make it a -1 not a -2 as the ad says, I would call Susan at Franklin engine (903)626-5210 she know all about the old Franks. and no i would not run mogas, the franklins have 14mm plugs that have a tendency to foul on 100ll, I think its a 1947 108-1 with a f150 a little more hp but not 178 hp at the price its a good deal but since things don't add up I would look at the plane in great detail ,since you cant run mogas Marvel Mystery oil and proper leaning will be a must

[pitman11 offline]

[robw56 offline]

I have had my 170 up to 13k once flying over Colorado with 2 aboard.... but it took a loooong time to get there. If you plan on doing a lot of mountain flying In Colorado I wouldn't get a 170 unless it had at least the 0-360 in it. Especially if you plan on hauling any weight at all. My Dad has a 108-3 with the 165 Franklin and it is pretty comparable to my 170 when flying with similair loads. He cruises a little faster though and I think his climb is just slightly better too. But he burns at least 3 more gallons an hour doing it.

[Soar07 offline]

Thanks, Based on all the valued comments here, I think that particular Stinson is off my list. Too many errors and omissions.

[Soar07 offline]

Thanks, Based on all the valued comments here, I think that particular Stinson is off my list. Too many errors and omissions.

But, I do wonder about aerodynamics mods on C170s or Stinsons. I had VGs on a Piper 140 years ago, and it made a huge difference. With that plus gap seals I added about 5-7 knots cruise and saw huge imrpovements in takeoff performance. I wonder about the ability to get similar gains in a 170 or a Stinson. For me fuel economy is very important, plus efficiency. I am an experienced glider pilot in Colorado, so low power doesn't mean the sky is falling. I would rather take a good low end plane, clean it up aerodynamically, and fly for a lot less than buy a big engine.

[Tadpole offline]

Thanks, Based on all the valued comments here, I think that particular Stinson is off my list. Too many errors and omissions.

But, I do wonder about aerodynamics mods on C170s or Stinsons. I had VGs on a Piper 140 years ago, and it made a huge difference. With that plus gap seals I added about 5-7 knots cruise and saw huge imrpovements in takeoff performance. I wonder about the ability to get similar gains in a 170 or a Stinson. For me fuel economy is very important, plus efficiency. I am an experienced glider pilot in Colorado, so low power doesn't mean the sky is falling. I would rather take a good low end plane, clean it up aerodynamically, and fly for a lot less than buy a big engine.

In a Stinson, you're at 10gal an hour regardless of Franklin 150 or 165, and maybe even the 220. The Cessna 170 has a lower fuel burn, and you can pull it back more if you wish for a slower cruise and economy....Franklin's don't like that, they need to be ran full on.

I know Matt has put VGs on his Stinson and he said he loves them, not sure that he gained any speed, having big tires on kind of removes that wish

[Soar07 offline]

I am starting to think VGs plus the leading edge cuffs and maybe wingtip extensions on a 170 could make it a high altitude machine. In soaring people go crazy looking for ways to kill drag, and small things add up. Yes, the 180hp option is awesome, but pricey.

Thanks for all the advice!

[Tadpole offline]

Yes, the 180hp option is awesome, but pricey.

Same with the big engine Stinsons.

[robw56 offline]

I am starting to think VGs plus the leading edge cuffs and maybe wingtip extensions on a 170 could make it a high altitude machine. In soaring people go crazy looking for ways to kill drag, and small things add up. Yes, the 180hp option is awesome, but pricey.

Thanks for all the advice!

The wing extensions are not STC'd in the U.S. for 170's, only in Canada. You can still do the Sportsman STOL kit and VG's though.

[Sullyco offline]

Cuffs, vg's, and wingtip extensions, do not "Kill Drag" .... wheel pants, wing root fairings, etc... kill drag

[Blu offline]

If you are flying in Colorado and want to save gas, much better a big engine dialed back than a small one running full out. plus when you are at 13000' on a hot day even a big engine is only making 60% if your lucky so fuel burn isn't that bad anyway. Manys the day at up high I wished for more power..... Can't remember wishing for less.

[Soar07 offline]

Cuffs, vg's, and wingtip extensions, do not "Kill Drag" .... wheel pants, wing root fairings, etc... kill drag

Fair enough depending on the application, but they do add lift. The VGs on my Cherokee 140 did killl drag, because they allowed a previously stalled portion of the wing to create lift by energizing the airflow in that wing section. The result was to create lift out of a wing area that used to only create drag. So, I call turning drag into lift, killing drag. Furthermore, I did use gap seals to kill drag on the same plane.

You are also missing something I didn't write. In gliders people do all sorts of things to kill drag and improve their aerodynamic situation. These may include taping over gaps, better seals on flight controls, or other parts of the aircraft, even lower drag air venting systems. All these things add up. My point was I have seen this stuff work in both gliders and powered aircraft.

If you can modify to reduce drag or create more lift, it can work very well. Or you can just pay more for gas and use a bigger engne.