The International Cessna 170 Association

Before I overhaul my C-145, it seems that I remember many years ago there were a couple STCs to swap the C-145 to-I believe a 180 with or without a constant speed prop.

Does anybody have any current information on that. I just want to be sure I am considering all my options. Zephyr, (very good reputation) just quoted me $28,600 for their fine overhaul. Plus $900 if I want a new camshaft. So my wallet is going to be hurting no matter what.

There are 2 good STC ,s around 1. Stoots of Alaska 2. Harry Delicker of California. However Harry has passed on but some one [chris] is still churning out the STC for his company . I fitted a Harry Delicker STC but a very good friend of mine has fitted a Stoots of Alaska STC fitted to his 170b . Having many hours flying and building the STC in both aircraft I feel the Stoots of Alaska Is the better STC these days as it gives you a greater choice of engines and props. Plus their advice over the phone is “second to none “ [ Aussie slang meaning great].

Your C145 @ $28K plus the cam cost doesn’t include remove/install labor does it? What about hoses and other misc? Does it include the carburetor? Mags? Alt or Gen? What about your prop reconditon? And your exhaust system? Engine mounts?

If those expenses hurt your wallet... Wait until you see the $50K the conversion to a 180 Lyc or 195/210 Cont.

If that doesn’t deter you, then I’d suggest the IO-360 Continental conversion. If money were no object that is the engine I’d go for.

The IO360 Continental STC is about $32K just for the STC
The IO360 Lycoming STC is about $15K, but uses a newer M1A or M1B engine that are more difficult to find used - new ones are about $32K plus a prop
The O360 Lycoming STC is about $15K, but uses the A1A or A1D that are more readily available
I did not price the O360 with fixed pitch, but expect the STC to be a couple thousand less, but not a lot less.

Then you need a prop - the factory prop on the A1A or A1D as found on Mooneys has a recurring AD unless you have the newer hub, but you're still looking at between $6-10K for a prop and governor on the used market

The newer composite props are about $15K with governor new with STC (Trailblazer or MT)

These are all off top of my head from conversations I had with each of the STC holders in December.

Then there's labor...so unless you can do all the work yourself, it's going to add a bunch more

I am going to “try”and compare apples to apples and not oranges . When I did my conversion I used Harry’s STC. It cost me $12000 but it had everything you would need with the conversion . Hoses ,engine mounts , instruments , nuts and bolts , Cowl parts for cowls to be modified . the only thing that wasn’t supplied was the coffee. All required paper work was supplied . My engine was supplied brand new from superior but in parts with all documentation [PMA] . That cost was about $23,000 but I had to assembled it. The assembly and hire of the test truck And all documentation was about $3000 and a couple cartons of beer. Due to a potential weight and balance issue it was decided to use a fixed pitch prop. The composite props were not really on the market then. I fitted a new sensenich fixed prop [new] costing around $3000. [very cheap] . How long I took to do the job??? About 48 labour hours . The issue here is I set myself goals of completion and then left it for another day . Eg. Fitting engine mounts to fire wall . That took about 2.5 hours . Just 4 bolts . [answering questions from on lookers and “expert”advisors”]
When I did Rodneys aircraft [170b] he had purchased his STC from Stoots of Alaska. Rodneys engine and prop came off a nearly new Cessna 172 that a Large cattle truck had backed over destroying the tail.fuselarge ,and the left hand wing. The engine wasn’t running and aircraft was tied down . He bought the wreck off the insurance company for $10,000. The engine had done only 340 hrs total. The front of the wrecked aircraft didn’t have a mark on it. Why so cheap ?? It was the access and position of the wreck and start of the wet season . Rodney paid for a helicopter to airlift it out and sling it 120 miles to a town. Cost was over $8000. The big issue with that conversion was the electrical/electronics pak on the fire wall. It’s wasn’t in the STC paper work . Rodney did most of the work over 12 months and sometimes he didn’t touch it for a couple of weeks .i did about 25 man hours on the aircraft and signed all the paper work. Stoots supplied most of the parts in the STC but a lot was used from the donor aircraft .
My advise on doing a conversion. Get all the paper work and approvals all sorted before diving in .dont be over whelmed by the volume. Do it stage by stage and double check your work. Have a qualified person keeping a eye on progress and if you hit a bump in the process contact the STC holder and have a chat about your struggles.

I have been asked to do another conversion on a Cessna 175. So much for retirement.

I flew Harry Deliher's conversion with a new constant speed prop for 12 years without any problems. I got the engine mount from Del-Air and it was a breeze to put the four bolts through. I tried another vendor for the mount and had problems so I returned it. The most difficult thing was the cowling change regarding the nosebowel. I found the fiberglass difficult to fit. Thirteen years ago I paid $6,000.00 for a new Hartzell prop which terminated the AD. The engine was an A1A-360. Del-Air has an STC to move the battery box back into the fuselage aft the storage area to assist in weight and balance. Before Harry passed, he was working on a 300lb useful load increase. You might want to inquire of Chris if that is available or if you can purchase it from a 172 conversion from another vendor. I don't know if the FAA recognized the 170 in the 172 increase in useful load. I would suggest that with the weight increase of the prop and engine, C180 would be a plus regarding this conversion. Realistically, I think you should be prepared for $45-50K in expense.

Performance wise, the fuel burn was 8.8 gal/hr at 2350rpm at 3-4K feet and 115kts. Winter days 1500ft/min was easy with just me in the plane. I easily carried four people as I new the 300lb useful increase was there, even though I didn't have the STC. I have no knowledge of the Alaska conversion.

How about the Stoots IO-370 Prime conversion coming any day...

The Franklin engine will be back in production any day... (where’s that tongue-in-cheek emoticon?)

I talked to Chris at Del Air. Definitely still a viable option there with his kit. Very helpful. A few months lead time. I might even do it...Sure is a lot of money when you start adding everything up....

FYI, he can do it as a constant speed or fixed pitch.

Has anyone used the Stoots Prime STC yet? Any feed back is welcome, thanks

I have been following the Stoots conversion very carefully as a new IO-370 engine is a very interesting engine . This one turned up out of the blue the other day in the hangar and I haven’t had the opportunity to talk to the owner.it appears This came direct from the manufacturer. It looks like a lycoming from a distance but it’s not a copy of the lycoming it’s different . So obtaining parts for it might be a issue. I would love to know the weight of it. It seems that you have to have a special exhaust for it .this engine only has 1 mag and the other is a “surefly”ignition system. I have been told it is to be fitted to a early Cessna 172. I wonder what’s their reliability ?