Overhaul or upgrade, what to do?

What should I do with 77C?

  • Overhaul the existing engine (cheapest)

    Votes: 8 34.8%
  • Upgrade to the Frankilin 180 (not quite as cheap)

    Votes: 2 8.7%
  • Upgrade to the Franklin 220 (less so)

    Votes: 5 21.7%
  • Bite the bullet, get a loan, upgrade to the Lycoming

    Votes: 7 30.4%
  • Cut my losses, eat $20k sell as-is and start over with something new.

    Votes: 1 4.3%

  • Total voters
    23
  • Poll closed .

alaskaflyer

Final Approach
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Alaskaflyer
Some of you might remember that my engine on 77C requires an unscheduled overhaul thanks to some metal ingestion. My 170B has the Franklin 165 horse engine with a fixed-pitch prop.

I've spent the past weeks investigating options, in-between traveling for work.

Turns out I have plenty of options, but each comes with advantages and disadvantages, and just as importantly, different price tags.

I can overhaul my current engine for about ten to fourteen thousand dollars if it doesn't need a new crank and most of the cylinders can be reused without their own overhaul. What I will get is the performance and aircraft I have now, with a "0" SMOH engine and brand new exhaust and airbox (which were just custom built - and paid for - just prior to the damage being found :( )

Or I can upgrade to a different Franklin engine, the 180 horsepower model or the 220 horsepower model, each coming with a constant speed propeller. Neither is a "drop-in" replacement for my current engine unfortunately (I had hoped otherwise.) The 180 horse is not as well known as the 220, but according to a couple of Stinson experts I have spoken to there is actually better parts availability for that engine than the 220 right now, and PZL-Poland is just as likely to restart production on new parts for the 180 as the 220. Many of the parts are identical to the 220 anyway, including cylinders. What I will get is a large increase in performance (either 180 or 220 max horsepower and the ability to use that horsepower on takeoff and climb thanks to the new propeller), a slightly larger recurrent maintenance cost (for the constant speed propeller) and I estimate the value of the aircraft will only increase $5k-10K. What I will have to pay? Well, anywhere between $20k to just under $30k. I would not be able to use my new shiny exhaust systems or airbox; I could probably sell the airbox to a Stinson owner but not the exhausts (custom for the Cessna installation.)

Or I can go with a conversion to a Lycoming 180 horsepower engine. This is the most expensive option because it requires the most modifications. I have a choice between a fixed-pitch propeller option (lest costly to purchase, less costly to maintain, less performance) or a constant speed propeller (vice versa.) It will cost upwards of $30k for the conversion once the smoke clears. The value of the aircraft afterwards will be the most improved, adding about $9K-20K of value depending on the market.

Or I can cut my losses, sell the airplane either as-is or airframe only and part out the engine to try to recoup as much as possible. I would expect to lose at least $15k of the original purchase price, maybe much, much more.

So, help me out. Vote on the poll (or the poll on my blog.) I need to make a decision soon, winter is coming!
 
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I can't answer for you Richard.

Do you love the plane? Is it your baby and you want no other? If so then you know what to do, upgrade it to the best possible plane it could be. If you cannot to commit to that level of love, then I suggest doing something less.
 
I can't answer for you Richard.

Do you love the plane? Is it your baby and you want no other? If so then you know what to do, upgrade it to the best possible plane it could be. If you cannot to commit to that level of love, then I suggest doing something less.
Quite frankly, if I were to move back to the CONUS I would probably sell it anyway and purchase a 182 or a 177 or somesuch. But there is a chance I will remain up here too, and the 170 is a perfect airplane for my missions up here. So at this point, with some questions about my future plans unaswerable, I only want to do what makes sense financially, keep it as un-emotional as possible, and get working on whatever I decide in the next few weeks so it just doesn't sit around corroding.
 
So at this point, with some questions about my future plans unaswerable, I only want to do what makes sense financially, keep it as un-emotional as possible, and get working on whatever I decide in the next few weeks so it just doesn't sit around corroding.

Is the 165 Franklin the original engine for the airplane? If so, I think you have only two real choices.

1.) Overhaul the original engine. Minimal cost out of pocket, you know what you will get, and potential buyers will be buying a stock bird.

2.) If you want to upgrade, bite the bullet and go all the way to the Lyco engine. More cost, but less scary for a potential buyer.

I'd be leery of spending on the higher horse Franklins, as to me anyway a potential buyer would be leery of buying a non stock non lyco bird.
 
Is the 165 Franklin the original engine for the airplane? If so, I think you have only two real choices.

1.) Overhaul the original engine. Minimal cost out of pocket, you know what you will get, and potential buyers will be buying a stock bird.

2.) If you want to upgrade, bite the bullet and go all the way to the Lyco engine. More cost, but less scary for a potential buyer.

I'd be leery of spending on the higher horse Franklins, as to me anyway a potential buyer would be leery of buying a non stock non lyco bird.
IIRC, the original engine was a 145 HP Continental. The Franklin was offered as an STC that was an "upgrade" at about the same cost of rebuilding the Continental.

If I could afford it, I would go with the Lycoming upgrade. If it would be a real financial hardship, then I would vote for the rebuild.
 
Send the Franklin to me to rebuild, if posible, I'll keep the cost at a minimum. Let us open it up, and see what we have. and then make the decision. after that you still have all your options open.

The Frank may be junk, or it may be repairable at a much lower cost than a complete overhaul. but we won't know that until we open it up.

I'll even do the upgrade at cost. if you wish.
 
IIRC, the original engine was a 145 HP Continental. The Franklin was offered as an STC that was an "upgrade" at about the same cost of rebuilding the Continental.

If I could afford it, I would go with the Lycoming upgrade. If it would be a real financial hardship, then I would vote for the rebuild.


Not true, the 165 franklin was an engine option offered by Cessna. see the type certificate it was offered on the "A" and "B" only.

The 180 horse Lyc ruins the 170, Every one I have seen after 500 hours the rivits are smoking, the gyros are worn out. alieron hinges are worn, and the cowling skins are cracking.

yes it does climb like crazy. but that is all. lycoming conversion yucky.
 
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Send the Franklin to me to rebuild, if posible, I'll keep the cost at a minimum. Let us open it up, and see what we have. and then make the decision. after that you still have all your options open.

The Frank may be junk, or it may be repairable at a much lower cost than a complete overhaul. but we won't know that until we open it up.

I'll even do the upgrade at cost. if you wish.

That's a very kind offer if I must say so myself.:cheerswine:
 
Tom, what happened with the IO-360 Continental conversions?? Did they ever get an STC for those??

I'd go with option "A"... open it up and see what's what. Then make the decision as to upgrade or not.

If I were to upgrade, I'd go with either option "B" or "C".
 
There are 2 IO-360 Continental conversions STCs available, John Benham owns one, and Tom Anderson ownes the other, both are approved for all 170s

Both of these conversions are more work than the Lyc. 180, but give you an injected engine with more horse power.

When considering the PZL Franklin read this

http://www.hangar9aeroworks.com/StinsonEngineOptions/108Engines.html
 
Quite frankly, if I were to move back to the CONUS I would probably sell it anyway and purchase a 182 or a 177 or somesuch. But there is a chance I will remain up here too, and the 170 is a perfect airplane for my missions up here. So at this point, with some questions about my future plans unaswerable, I only want to do what makes sense financially, keep it as un-emotional as possible, and get working on whatever I decide in the next few weeks so it just doesn't sit around corroding.

ooooh! never give up a good 170 for a 177! .lighter. just about as fast and none better! put the HP into it and a CS prop I wonder if it would not out perform the others! I loved my limited time in a 170B versus 172's. The 170 had it in all aspects except a nose gear... and I'm not sure really how much that accounts for..(less than 10 hours in a 170B, but I loved the airplane, fine flying machine.)
 
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Not true, the 165 franklin was an engine option offered by Cessna. see the type certificate it was offered on the "A" and "B" only.
I stand corrected.
 
None of the above, put the Cont IO 360 on it, you get 195 hp with that don't you?
 
None of the above, put the Cont IO 360 on it, you get 195 hp with that don't you?

There are horror stories about doing this mod on the 170 web page.

When using John Benham's STC you must manufacturer all the parts to the mod. He just gives the engineering paper work. That's all.

Tom Anderson has a kit if you wish to buy it, it is expensive, but contains the engine mount, header tank, fuel caps, fuel lines and a bunch of other stuff.

The thing about converting the 170 from a Franklin to any other STC is the cowl has been modified to fit the frank. The whole lower cowling skins must be changed back to the OEM. And Richard just had a repair done there, so now you will have a patch on a patch (sort of) but if you go with the IO-360, you can use a earley 172 cowl, and there are plenty in the salvage yards. but they ain't cheap.

Advantages to the IO-360 (tom Anderson version)

1 horse power
2 smooth running
3 auto gas
4 Vac system
5 Fits under the un-modded cowl.
6 choice of props
a. constant speed
b. Fixed, metal or wooden if you please
c. hot prop if you want (requires a field approval) it feathers, and is heavy.
7 no carb icing
8 better cabin heater
 
There are horror stories about doing this mod on the 170 web page.

When using John Benham's STC you must manufacturer all the parts to the mod. He just gives the engineering paper work. That's all.

Tom Anderson has a kit if you wish to buy it, it is expensive, but contains the engine mount, header tank, fuel caps, fuel lines and a bunch of other stuff.

The thing about converting the 170 from a Franklin to any other STC is the cowl has been modified to fit the frank. The whole lower cowling skins must be changed back to the OEM. And Richard just had a repair done there, so now you will have a patch on a patch (sort of) but if you go with the IO-360, you can use a earley 172 cowl, and there are plenty in the salvage yards. but they ain't cheap.

Advantages to the IO-360 (tom Anderson version)

1 horse power
2 smooth running
3 auto gas
4 Vac system
5 Fits under the un-modded cowl.
6 choice of props
a. constant speed
b. Fixed, metal or wooden if you please
c. hot prop if you want (requires a field approval) it feathers, and is heavy.
7 no carb icing
8 better cabin heater
OK! OK! you sold me! :D I will take two, one for Richard and one for me!:yes: Now, where did I leave my checkbook?:goofy:
 
OK! OK! you sold me! :D I will take two, one for Richard and one for me!:yes: Now, where did I leave my checkbook?:goofy:

I'll fly over to Tom's tomorrow, and get your two kits, I know you are good for it. Do you want me to come up and get your 170? or would you like to drop it off.
 
What's the difference between the 108-3 Station Wagon and the 108-3 voyager ?

To be honest, I don't really know... :dunno: I've always called the 108's Wagons since thats what the guys at the airport called them.

If had to venture a guess, I'd say the Wagon either had an extra seat in the baggage, or an extra door...
 
To be honest, I don't really know... :dunno: I've always called the 108's Wagons since thats what the guys at the airport called them.

If had to venture a guess, I'd say the Wagon either had an extra seat in the baggage, or an extra door...

The interior trim, Logos, and Stinson used a heavier plywood on the floor of the rear seat/baggage compartment.in the "flying station wagon".

I once met a guy in Spring House BC that bought 3 station wagons from Stinson in 1948, he packed camps, flew highline patrol, and mail contracts until 2005, When I talked to him the 3 had in access of 25,000 on each of them.

OBTW they all had the original Franklin 165's in them.,
 
Richard,

I've been watching your blog for updates... what did Tom find when he opened up the engine?!
 
Richard,

I've been watching your blog for updates... what did Tom find when he opened up the engine?!

Due to circumstances in the frozen north, I have not seen the engine yet.
 
The engine arrived my house today, We got the call from the freight company at 1130, and it was in Fife Wa waiting for pick up. So Barb and I jumped in the truck and headed south 2.5 later we had the engine in the truck. AS we headed home i started hearing strange noises from the Dodge, as the farther we drove the louder it got untill we got home the truck was actually jerking as we backed in to the drive. Sounds like the rear gear train is shot.

But I'll get the engine torn down as soon as possible and see what is wrong with it.
 
I disassembled the Franklin and found it had a loose castle nut flooating around in the crank case, and had gotten caught between the case and the crank and knocked a chunk off of the case. (I don't know if the case is cracked yet)

Yesterday I got the cases split and discovered that the nut that I assumed was left over from the repair in Canada when the cylinder was replaced was actually a nut that was from a broken main bearing stud on #3 main bearing. It looks to me as just plane old fatuge that caused the stud to fail.

pictures below
#1 is the engine on the stand
#2 is the debris found in the oil pan
#3 is the two studs that hold the #3 main bearing
#4 is the same bearing after 1 case was removed
#5 The nut matches the stud exactly
#6 is the simplstic design of the Franklin accessory gears, 1 cental gear drives both mags & the generator, the large gear is the starter ring gear. the cam and crank gears are under the stack.
#7 Is the crank and cam gears
#8 is the hit on the case.
 

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In pic 8 it sure looks like there is a fracture. I hope I am wrong and the case can be repaired
 

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Did you notice the crack in the cylinder skirt?
 
Did you notice the crack in the cylinder skirt?

Yeah, the case looks ok from what I could see. If you look in the 2oclock position of the picture of the bolt, it looks like there was a possible developed inclusion in the bolt which in that application would make me suspect the bolt wasn't torqued properly (under torqued) when last assembled.
 
Yeah, the case looks ok from what I could see. If you look in the 2oclock position of the picture of the bolt, it looks like there was a possible developed inclusion in the bolt which in that application would make me suspect the bolt wasn't torqued properly (under torqued) when last assembled.

That is the bottom of a cylinder hold down stud screwed in from the outside of the case.
 
That is the bottom of a cylinder hold down stud screwed in from the outside of the case.

I was talking about the broken surface of the stud that mated to the piece in the nut, the sector where the break began.
 
I was talking about the broken surface of the stud that mated to the piece in the nut, the sector where the break began.

The nut that made the impression in the case came from a main bearing clamp stud.
 

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Found this thread wandering the internet researching Franklin engines...

Tom...I am looking at a '46 Stinson with a 165 Franklin...900 or so hours SMOH...

How did this work end?

How is the support for these engines?
 
Found this thread wandering the internet researching Franklin engines...

Tom...I am looking at a '46 Stinson with a 165 Franklin...900 or so hours SMOH...

How did this work end?

How is the support for these engines?
This work ended up being a great running F-165 that is for sale now.

your Stinson came from the factory with the 165 heavy case, they were great engines and have good support from several parts collectors and and after market suppliers.
 
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