I know that this is a popular topic and have read many threads on BCP about upgrades, costs, benefits and whether its worth it or not.
I know people say its a lot of money, and your better off getting a 180.

I'm a former super cub pilot who likes the ability and comfort to land in small strips and have a plane that can climb and get itself off the ground with room to spare. I know the 170 is no cub, but I am happy to have a little more space and the ability to haul a little more gear and people.

I have a newly acquired 1953 cessna 170B with Horton Stol, 180 gear and about 2500TT that i am thinking about converting

From what I can understand there are basically four STC engine options
Avcon - Del Aire - Stoots all doing 180hp lycoming o-360
xpmods with the 210HP continental io-360

Looking to get info from any one thats done an engine swap in the last year or two, on who they used, how it went and what they would recommend.

Thanks from a new member on BCP

FWIW theres also a Franklin 220 conversion. Worked on one of them and it was a great airplane. Performed very well.

A1Skinner wrote:FWIW theres also a Franklin 220 conversion. Worked on one of them and it was a great airplane. Performed very well.

I have read a bit about the Franklin engines, but last thing I heard the engine was out of production and hard to come by so left it off my options list.

Talk to Dave Stoots. He has approvals for injected engines as well. He’s been working on other conversions.....like an IO-375. Should be a real hot rod.

If I were going down that rabbit hole, I’d do the fuel injected kit in a heartbeat.

To the best of my knowledge, the Avcon kits are no longer available, and if they’re still owned by the same folks, you wouldn’t want to deal with them. But I think that STC is dead.

The owner of Del Aire passed a while back, I understand his son was trying to get approvals from the FAA to go back in production. I’d find out if that’s happened yet.. Del Aire’s kits and other stuff has always been top notch.

I personally would shy away from the Continental conversion, if it’s available, just based on projected engine life. Short tbo on those engines, and for good reason.

Franklin? Really? You’d have to REALLY, REALLY want an oddball engine to go to the expense of that conversion with a Franklin. Franklins are good engines, but the company has changed hands so many times who knows if they even answer the phone. Until some reputable company puts those engines back in production, I wouldn’t even consider one. They do make power, though.

Call Stoots and Del Aire and get the real scoop from the horses mouth. Oh, by the way, Stoots will talk your leg off . But he makes good stuff.

MTV

https://backcountrypilot.org/forum/c-17 ... lete-14688

PM me any specific questions if you like.

-DP

First thing I would do if you want max performance is remove that Horton STOL kit and replace it with a Sportsman.

I would use a Lyc for the engine conversion and us an MT Ultra prop!

Some BAS shoulder harness and a fuel computer and you are all set!

Kurt

I'm in the process of putting the TCM IO-360 on my 170.
It's a lot of work and a LOT of custom fabrication. The exhaust re-uses the C-145 exhaust with custom welded risers. I'm not convinced that an exhaust designed for a 145HP motor is right for a 210HP motor but, here we are.

There is only one spinner that looks good, is only available from the STC holder and costs twice as much as my used McCauley

Instructions are less than detailed. If you're expecting step-by-step, step away from this STC.

Although I'm gonna LOVE the end result, if I had to do it over again; I'd be on the phone with Stoots.

I have flown behind both IO conversions and they turn the 170 into a excellent performer. The Lycoming would be my choice due to the simpler install and longer TBO of 2000. The Continental Is statistically not as reliable and a TBO of 1500. Mr. Stoots is a handful and if you have the time, tell him you want to use the MT prop over the Hartzell. Prepare for a heated exchange that is completely one sided.

akgreg wrote:I have flown behind both IO conversions and they turn the 170 into a excellent performer. The Lycoming would be my choice due to the simpler install and longer TBO. The Continental Is statistically not as reliable. Mr. Stoots is a handful and if you have the time, tell him you want to use the MT prop over the Hartzell. Prepare for a heated exchange that is completely one sided.

VERY diplomatic..... That’s a great way to get an earful.

MTV

such anti-Franklin bias!

mtv wrote:I personally would shy away from the Continental conversion, if it’s available, just based on projected engine life. Short tbo on those engines, and for good reason.

Second time you've said this recently so I have to ask, whats the good reason? I realize I'm biased because I put one in my plane but only did so after extensive research; actually talking to people, reading tech documents, etc and not just believing what google tells me. But I've never operated one and could have easily missed something while looking at engine options.

Lots of people have ran these engines past TBO...what part 91 operator cares about TBO these days anyways. The ES version has a 2000hr TBO (2400hrs if built after 2012 and operated frequently) and the only difference is the intake manifold. Since the ES isn't and option your stuck with a 1500hr TBO (1900 if built after 2012 and operated frequently) Lycon stated that these engines aren't any more expensive to overhaul than any other 6 cylinder engine and will make more than rated horsepower without their cylinder magic. I found out that overhaul can be expensive if you have to buy oversized bearings...those things are expensive (3200$). It is the most fuel efficient aircraft engine made based on the BSFC rating. Only first hand complaint I found was from a mechanic that has been maintaining piston engine airplanes for a few decades. He was always fighting oil leaks from the valve covers because there are two per cylinder. Has the same issue on some 550s.

The bad rap these engine have comes from ham-fisted pilots attempting to operate the poorly designed manual wastegate used on the turbo charged version of the IO360 installed in Mooney's. Over-boost the engine, blow a cylinder and now it is the engines fault and the whole series of engines gets known for blowing cylinders.

The Lyc O360 is a great engine and the starting system is far superior to the Continental starter adapter garbage. The main thing I dislike about the O360 is the limited prop choices. Only long metal prop option is a 80" Hartzall that requires a heavy and expensive damper. If your good with a MT then this is no factor.

If Franklins were still in production I'd be installing a 220 in my plane.

denalipilot wrote:https://backcountrypilot.org/forum/c-170b-io-360m1b-conversion-complete-14688

PM me any specific questions if you like.

-DP

Just read the whole thread. Plane looks amazing and exactly what i am after, going to give stoots a call today, will PM you with some questions as i move along.

thanks
tbabbott

whee wrote:

mtv wrote:I personally would shy away from the Continental conversion, if it’s available, just based on projected engine life. Short tbo on those engines, and for good reason.

Second time you've said this recently so I have to ask, whats the good reason? I realize I'm biased because I put one in my plane but only did so after extensive research; actually talking to people, reading tech documents, etc and not just believing what google tells me. But I've never operated one and could have easily missed something while looking at engine options.

Lots of people have ran these engines past TBO...what part 91 operator cares about TBO these days anyways. The ES version has a 2000hr TBO (2400hrs if built after 2012 and operated frequently) and the only difference is the intake manifold. Since the ES isn't and option your stuck with a 1500hr TBO (1900 if built after 2012 and operated frequently) Lycon stated that these engines aren't any more expensive to overhaul than any other 6 cylinder engine and will make more than rated horsepower without their cylinder magic. I found out that overhaul can be expensive if you have to buy oversized bearings...those things are expensive (3200$). It is the most fuel efficient aircraft engine made based on the BSFC rating. Only first hand complaint I found was from a mechanic that has been maintaining piston engine airplanes for a few decades. He was always fighting oil leaks from the valve covers because there are two per cylinder. Has the same issue on some 550s.

The bad rap these engine have comes from ham-fisted pilots attempting to operate the poorly designed manual wastegate used on the turbo charged version of the IO360 installed in Mooney's. Over-boost the engine, blow a cylinder and now it is the engines fault and the whole series of engines gets known for blowing cylinders.

The Lyc O360 is a great engine and the starting system is far superior to the Continental starter adapter garbage. The main thing I dislike about the O360 is the limited prop choices. Only long metal prop option is a 80" Hartzall that requires a heavy and expensive damper. If your good with a MT then this is no factor.

If Franklins were still in production I'd be installing a 220 in my plane.

Whee,

The 1500 hour tbo is what I was referring to. I’ve talked to several operators that replaced cylinders at around 1200 hours....at least one or two. Non turbo charged engines in Hawk XP. As you say, there’s no question that operator technique probably has a lot to do with this. Nevertheless, you don’t hear as much about replacing cylinders in four cylinder Lycomings. And the same class of folks operate them.

As to concerns over tbo being irrelevant in Part 91 ops, try selling an airplane with engine close to tbo and let us know how that effects price.

If I were looking for an airplane that was already converted, and came across a good one with this engine I’d jump on it. But that wasn’t the question......the question was about converting one......

MTV

Thanks MTV. Cylinder life is an issue that affects most Continentals but not Lycomings.

whee wrote:Thanks MTV. Cylinder life is an issue that affects most Continentals but not Lycomings.

True. But I hear of very few continentals needing cams before TBO and have heard of a few lycs needing them. I guess it's always something...

A1Skinner wrote:

whee wrote:Thanks MTV. Cylinder life is an issue that affects most Continentals but not Lycomings.

True. But I hear of very few continentals needing cams before TBO and have heard of a few lycs needing them. I guess it's always something...

I'd rather have cylinder problems than cam problems.

Comparing IO-360 to IO-360 is one thing
Comparing STC to STC is another

Cam corrosion in Lycomings is easy to avoid: Fly the dang thing. If you can’t fly for a period of time, pickle the engine. And, use camguard with oil changes.

And, don’t buy a Lycoming engine that’s sat without flying for years without factoring in the cost of a cam, plus down time.

MTV

I've got about 1000 hours in the last 18 years on my TCM IO-360KB in my 170B. Factory Reman. Done per XP mods STC.

The IO-360KB has a 2000 hour TBO, and has seemed to wear well. Last annual compressions were still in the mid 70s as they have always been. Valves and cylinders still look good with the boroscope. Very happy with performance, operation, smoothness. This engine never gets too hot, cruise CHTs 330-360 on a warm day, +25 or so in climb. Cold days I wish I had cowl flaps.

YES, there is a lot of fabrication work. Fuel tanks need to come out and get return lines welded, there's a header tank, another fuel valve forward of the header tank, vents get moved. different baffles. different and more engine control cables. Now with the heavier engine and that constant speed prop and governor up front, you need to move the battery aft, add a baggage door so you can get to the aft battery, etc.Depending on how it weighs out, might need some ballast in the tail. And there's more. It's a complex swap and was expensive, but I have never regretted it.

What would I do differently?

The weight and balance are an issue- mine is still a bit heavy at 1460 and the CG further forward than I would like. Two big guys up front and full fuel requires throwing a few pounds in back. I have considered going back to a fixed pitch prop which would shed quite a few pounds off the nose. Of course, so would an MT prop. (more $$$)

Cheers,
Pete

I just got off a long long phone call with Chris at Del-Air. I have a customer who wants to do a 180HP in his 170 and have been doing my research. I also have been revisiting the idea (and numbers) of putting the O-360 in my 170B Trainer project. If I go this route, I will use his STC for sure. He is a super helpful guy and a real pleasure to chew the fat with. Worth a call if you want to get some info.

FWIW... I chided him pretty hard about his lack of web presence and keeping his head low. I encouraged him to join BCP and sent him this thread. I know he'd be a real great resource to the community.

Chris... Chris... come in Chris.... Do you read me?

Bigrenna wrote:I just got off a long long phone call with Chris at Del-Air. I have a customer who wants to do a 180HP in his 170 and have been doing my research. I also have been revisiting the idea (and numbers) of putting the O-360 in my 170B Trainer project. If I go this route, I will use his STC for sure. He is a super helpful guy and a real pleasure to chew the fat with. Worth a call if you want to get some info.

FWIW... I chided him pretty hard about his lack of web presence and keeping his head low. I encouraged him to join BCP and sent him this thread. I know he'd be a real great resource to the community.

Chris... Chris... come in Chris.... Do you read me?

I keep hearing people say that Del-Air isn't doing engine STCs anymore.
Very glad to see that's not the case. Would love to see him join BCP as well.

c170pete: if you're looking for a fixed pitch for the TCM 360, I have two of them.