I0-360 STC discussion?

[marathonrunner]

I lost two bids over the years and the same mechanic got them. One was a 206 that needed reskinning from the rear cargo door aft. He did not jig it or even attempt to build one to jig it in prior to removing the skins. When it was done, the tail had a very extreme noticeable twist. Several years later, same guy same problem only a Saratoga. OH yeah same twisted results.

Thus proving you can do the same thing wrong for years and call it experience. Also life is tough and tougher if you're stupid.

[avoight]

Having just completed a significantly simpler engine mod this past few years with a 220 Franklin on my 172 TD, I would say you are in the ball park, but not low for sure. All of the odds and ends add up in a hurry. A real hurry if you use new parts. All new plumbing, new controls, most of your engine side of the panel and related sending units, and a six cylinder engine monitor is a must for these engines (I went with a JPI 930, as it worked out to about the same cost as the minimum individual gauges and a GEM), battery relocation, or Atlee Dodge upgrade kit, seaplane bushings for the firewall attach points, solenoids, misc wiring, circuit breakers, etc. and key switch or push button for the pull starter replacement. These are just a start. Del Air fuel tank upgrade looming on the horizon... The IO-360 mods I have seen required new cowlings, as it would be a tough squeeze under the C-170 tin. On another positive note a C-180 with this many new parts would not be cheap either and it would burn more gas! Likely never would have done it if my crystal ball had told me a decent C-180 would sell for what they are today, but it puts a grin on my face every single time I fly it.

[Kyle]

This really is a great discussion and an informative exercise for me anyway. I just love tinkering with airplanes and enjoy spinning wrenches as much or in some cases more than flying them. The read on owner produced parts was helpful too. For me I’m about half way (I hope) through my current C-145’s run. By the time I retire in a few years, actually just change professions, I’ll be ready to change this engine. I think the advice here about starting the conversations with the PMI for our shop is the first step. If that looks favorable, the way I probably would work this is perhaps contact Tom Anderson and get his STC / drawings etc. first – then I have it. Then start on the mount, all the while collecting parts and pieces as needed. I can’t ever justify the money I spend on my 170 but by the time I retire I’d have some of the hurdles done. We have some junk 337’s around here so a core IO360 and rear engine mount from a 337 might be easily obtainable. Not sure if a shop would even want the mount to modify, or start anew but it’s a question to ask.

Of course other options are the Stoots Conversion or just leave the C-145 as is…

[bagarre]

The 337 mount is a good starting point because the bed is the same (so I've been told).
There is also the field approval to have a Maule motor mount modified (maybe). But there is no supporting data for it.

In my case, I think I'll buy the paperwork once the local Feds agree I can have the mount made.
After that, I'll collect all the parts over the next few years until it hits critical mass.

I even thought about getting a 170 firewall and cowl to build everything in my garage first so I dont have to take the plane offline for a year while I do the swap.

[bigrenna]

delete

[marathonrunner]

marathonrunner wrote:
doesn't the starship enterprise run on tri lithium crystals?


It's Dilithium. Geeze!




http://en.wikipedia.org/wiki/Dilithium_(Star_Trek)

I thought they upgraded on some planet to tri lithium...my bad just not a real Trekkie..Beam me up Scottie, no sign of intelligent life here

[blueldr]

In the above comments, avoight mentions a difficulty in gettion the IO-360 inside the cowling and needing new "tin". On my conversion I reversed the top intake runner system and angle trimmed the front end of one runner. Other than that, no modifications were made to reinstall the original '52 model cowling. No "cheek bumps" needed either.

[bagarre]

Dick is right.
Reversing and trimming the intake tubes is also approved via the STC and everything fits under the original cowling. Even the exhaust exits the original openings. If done right, the only give away to the bigger motor is the prop, spinner and shorter takeoff distance.

The Lycoming 360 requires blisters in order to fit and the exhaust is quite different..

[ak2711c]

Yeah mine easily fit under my cowl too and regarding the need for bigger fuel tanks, I have better range with the IO-360 than I did with the stock motor because of how much faster it goes. I have no doubt you could find a comparable c-180 for the same or less money than doing the conversion but a stock motored 180 won't even come close to the performance of a 170 with an IO-360. The only thing a 180 has on the 170 is more useful load and even that often times is not more than 100-150 lbs. You have to get into the 180's with the 520 in them in order to even have a chance of comparable performance, but then you have $20,000- $50,000 more into your 180 than you do the 170 with the IO-360 in it. Then comes the 185 argument. Having said all this it is always cheaper to by one already converted than to do it yourself. The IO-360 170's are hard to find and usually don't last long. I know I wouldn't trade mine for any 180 with any motor no mater how nice it was. The only way I would choose a 180 over a 170 is if it was a choice between a stock motor 170 or a stock motor 180. Just my two cents.
Shawn

[ak2711c]

I just read my post and didn't mean to come across so anti 180. For me in my application my love is off airport flying. I need a plane that I can put a whole moose in and still operate in and out of a 500' strip or if I am empty operate in and out of a 200' strip and one that I can occasionally carry 4 people in. It also needs to be light enough that I can push it around by myself if I am stuck in snow or soft soils. A 180 is 300-500 lbs heavier than mine and just isn't capable of doing those things. If your application is different a 180 might be the plane for you.
Shawn

[marathonrunner]

The 180 is not as good on floats for performance as the 170 with the O-360 so I imagine the IO-360 is even better

[blueldr]

When we discuss the appearance change in the C-170 with the IO-360 engine, the first year I flew mine with a FP prop and the only apparent difference was the custom exhaust exiting the bottom air gap.
I have a friend, Stan Jost, who has one of the first conversions that Tom Anderson did using a FP prop and a stock type exhaust. His airplane looks dead stock. He has been flying it on the same engine without an overhaul for about thirty years.

[avoight]

In the above comments, avoight mentions a difficulty in gettion the IO-360 inside the cowling and needing new "tin". On my conversion I reversed the top intake runner system and angle trimmed the front end of one runner. Other than that, no modifications were made to reinstall the original '52 model cowling. No "cheek bumps" needed either.

My apologies for the "mis-information" the only one I have come across here in Canada had the cowls replaced. Possibly to incorporate cowl flaps or maybe just to change the look? Not that there is anything wrong with the look of the stock cowls You would certainly need new baffling though, so my statement was not totally wrong...

[avoight]

Yeah mine easily fit under my cowl too and regarding the need for bigger fuel tanks, I have better range with the IO-360 than I did with the stock motor because of how much faster it goes. I have no doubt you could find a comparable c-180 for the same or less money than doing the conversion but a stock motored 180 won't even come close to the performance of a 170 with an IO-360. The only thing a 180 has on the 170 is more useful load and even that often times is not more than 100-150 lbs. You have to get into the 180's with the 520 in them in order to even have a chance of comparable performance, but then you have $20,000- $50,000 more into your 180 than you do the 170 with the IO-360 in it. Then comes the 185 argument. Having said all this it is always cheaper to by one already converted than to do it yourself. The IO-360 170's are hard to find and usually don't last long. I know I wouldn't trade mine for any 180 with any motor no mater how nice it was. The only way I would choose a 180 over a 170 is if it was a choice between a stock motor 170 or a stock motor 180. Just my two cents.
Shawn

I agree with most of your points, and as you, would not trade my upgraded HP light Cessna now that the pain of getting it done is over, for a stock 180. My Franklin conversion gives me significantly better range and about the same endurance as the old O-300, but I found the tanks small with that engine as well. I am not alone in this or Harry D. would not have bothered with his Fuel Tank mod kits. (which I feel are also better than the C-180 bladder style tanks, another plus for the 170) The other point I was trying to make is the cost of doing the conversion is only really justified if you already have a 170 that you have invested a lot of love, labour and money into already, and can't bear to part with. And that no longer meets your needs in its current powerplant situation. Starting from scratch it would be close to the same money to buy a 180 or 182 and do the PPONK conversion or similar just about every way you look at it. Particularly from the resale angle.

[ak2711c]

I don't disagree that it would be nice to have a little more fuel available. My point was that the argument is often made that because you have a bigger motor now you need more fuel capacity when you actually need it less than you did with the stock motor. I also agree that converting a 170 to more HP would cost about the same as converting a 180 to more HP if you do the PPONK conversion however the price of the stock average condition 180 is going to be about $30,000 more than a stock average condition 170. So if you start with a $35,000 170 and put a $45,000 engine conversion on it you have $80,000 in it. If you start with a $65,000 180 and put a $45,000 engine conversion on it you have $110,000 in it. If you chose to do a IO-520 upgrade instead of the PPONK all bets are off, the cost really gets crazy then. One big benifit to doing the PPONK on the 180 is you have a good chance of getting most of your money back in resale, with the 170 the chances are pretty slim of ending up right side up. But then I didn't convert mine to raise the resale value.