C-170 Aiplanes With Cont.IO-360 Engines

[GAHorn]

Two reasons the TCM IO-360 makes so much more power with only 60 more cubic inches is fuel injection efficiencies and cross-flow intake/exhaust. (Constant speed prop and compression ratio (8.5:1) also helps, of course.) I've always been fascinated that this is the engine Cessna eventually put in the airframe (rather than a Lycoming) when they produced it as a military trainer (T-41).

If you are looking for a version which might use 80/87/mogas then the IO-360-B was certified at 6.5:1 compression and could use those fuels.

[GAHorn]

Yea George, I had forgotten about that pristine one out west. I guess the ones I am not seeing are the 55/56 models. There are probably some around, I just haven't seen them. That would make a nice conversion on Ole Pokey, ...

Then you'd have to change the name!

Seriously, the "pressure cowl" was introduced with the 1953 model-year (beginning with SN: 25373) and remained for the rest of the B-model production, therefore any 1953 B-model and subsequent would have the same cowl, so any 55/56 model would be no different.

[blueldr]

The compression ratio of 6 to 1 on an IO-360 sounds exceptionally low considering that the O-300 is supposed to.be 7 to 1 on a much older design.

As far as operating the IO-360D that I had on my conversion, it seemed to thrive on Regular Auto fuel rated at 87 octane as listed on the dispensing pump
and also tested at 5% alcohol as did all of the fuel I tested here in California. One thing I know for sure is that you'll never have to clean a spark plug when running on mogas.

[GAHorn]

Good catch, bluEldr! I mistyped it. It's 6.5:1 and I corrected/edited my earlier post.
Here's the type cert data on the entire IO-360 series, which gives the info:

IO-360 Ty-pe Cert E1CE.pdf

(21.88 KiB) Downloaded 212 times

[hilltop170]

Losing 30hp would be counter productive but being able to use car gas would be a plus.

[GAHorn]

Losing 30hp would be counter productive but being able to use car gas would be a plus.

IF...you can find car gas that didn't have ethanol. (It may be a moot point everywhere now.)

[blueldr]

In reference to mogas without ethanol, there was an advertisement in a recent issue of the Idaho Aviation Association
"The Flyline", page 6, from Inter-State Aviation, Inc., located at the Moscow (ID) Pullman(WN) Airport. They state that they now have
"Alcohol-Free car gas (unbranded) now availabe at our pump". I'm going to call them to try to find out their source. There does
not seem to be any such source available here in my area.
There are quite a few of the Rotax 912 engines in use at my airport and those do not like 100LL gas, but all the local 9i oct mogas
contains 5% ethanol. It seems that the oil called for in that engine has a bad reaction with the TEL in avgas.
A lot of the other guys would like to find a source of alcohol free mogas just to keep"legal".

P.S. A telephone call to PUW informs me that the fuel comes out of Billings, MT. Further investigation follows.

[minton]

Carburetors are not the only issues when trying to convert from fuel injection. The intake (induction system) tubes and cylinder ports are sized smaller and in most cases the compression ratios are different. If you just bolt on a carburetor and start her up she's not going to be happy. It will be running considerably leaner. This will express itself by not producing rated power and a very good chance of detonation and high cylinder head temperatures.

Data plates are also in need of an update. Good luck with that

[Brad Brady]

In reference to mogas without ethanol, there was an advertisement in a recent issue of the Idaho Aviation Association
"The Flyline", page 6, from Inter-State Aviation, Inc., located at the Moscow (ID) Pullman(WN) Airport. They state that they now have
"Alcohol-Free car gas (unbranded) now availabe at our pump". I'm going to call them to try to find out their source. There does
not seem to be any such source available here in my area.
There are quite a few of the Rotax 912 engines in use at my airport and those do not like 100LL gas, but all the local 9i oct mogas
contains 5% ethanol. It seems that the oil called for in that engine has a bad reaction with the TEL in avgas.
A lot of the other guys would like to find a source of alcohol free mogas just to keep"legal".

P.S. A telephone call to PUW informs me that the fuel comes out of Billings, MT. Further investigation follows.

In our area, we have a distributer that has alcohol free fuel. Myer oil out of Ashcum IL. The only place I have seen their fuel is Paxton airport. Also, Cushing field has mogas, I think they get there fuel from Carlson, out of Newark. I would trust either companys......Brad

[blueldr]

minton,
in reference to your above comment about caruretors on fuel injected engines being "unhappy".
1. How about the Cont. O-470 when "P Ponked" with IO-520 cylinders that maintains the O-470 carburetor?
2. How about IO-520 engines installed on C-180 and C-182 airplanes using the O-470 induction system with a carburetor
rather than switching to a fuel injection system requiring installation of a header tank, fuel boost pump, and a fuel return system?

They appear to be "Happy" runnng systems.

[hilltop170]

Carburetors are not the only issues when trying to convert from fuel injection. The intake (induction system) tubes and cylinder ports are sized smaller and in most cases the compression ratios are different. If you just bolt on a carburetor and start her up she's not going to be happy. It will be running considerably leaner. This will express itself by not producing rated power and a very good chance of detonation and high cylinder head temperatures.

Data plates are also in need of an update. Good luck with that

The idea was to explore the possibility of an STC. Since the IO-360 is currently in production, it would be a good replacement for the C-145/O-300 series if it is feasible.

[hilltop170]

minton,
in reference to your above comment about caruretors on fuel injected engines being "unhappy".
1. How about the Cont. O-470 when "P Ponked" with IO-520 cylinders that maintains the O-470 carburetor?
2. How about IO-520 engines installed on C-180 and C-182 airplanes using the O-470 induction system with a carburetor
rather than switching to a fuel injection system requiring installation of a header tank, fuel boost pump, and a fuel return system?

They appear to be "Happy" runnng systems.

After 950 hours of flying a 1958 C-180 with an IO-520-D engine fitted with a carburetor under the P-Ponk mod, I can assure you of one thing, I am happy.

I can't really see why an IO-360 would not be just as happy as long as the induction system would accept a carb. I was hoping someone might have already checked out what would be required to use one.

[GAHorn]

It'd take an unusual induction system since downdraft carbs are not favored on airplanes. The IO-360 cylinders have their intake valve inlets on top.

[minton]

BL,

Sizing (airflow)and jetting (fuel flow). I think that I qualified my earlier smaller induction statement. Just reread, guess I did'nt There are some engines/cylinders out there that are used interchangebly between injection and carbureted. Don't think Lycoming does.

Anyhow, the P Ponk engine I operated ran pretty rough in comparison with the stock O-470. Guess that should be expected when churning out more HP.

Have you seen a down draft carb system for O-360?? Side draft?? Maybe a rear mounted up draft???

Wish that I could find a complete IO-360 kit for my B. I have a complete 200 hour lyc O-360-A1A Del-Air kit.

[170C]

An IO-360 Continental conversion on a B model 170 (or my 172) has often whetted my appetite,not my pocketbook Some have advised if more power (hp) and/or climb performance/speed were desired that it would be false ecomomy to do a conversion on a 170/172 and that selling said airplane and replacing it with a C-180, which would have none of the compromises of a conversion (mfg'd with heavier gear, larger fuel tanks, higher gross wt/useful load, etc). I recall one menber at a convention 5+ yrs ago having a 170 with a Franklin engine who stated his plane would out preform a C-180 speed wise and climb rate. Don't know how accurate that is/was as no numbers were provided. Aside from the obvious desire to retain the rounded tailfeathers of the 170, this may be sound advise However, what are we possibly gaining from the expensive conversion It would be interesting to hear from those with C-170's (or even a 172) that have the Continental IO-360 and CS prop regarding REALISTIC day-to-day performance. Climb rate at gross wt; cruise at 5000-7500 ft at "normal" power settings; fuel burn at that power setting; endurance at that pwr setting, etc. I know of one member who has given me some figures in past times (I don't recall the specifics) that indicate his aircraft can cruise somewhere around 130-140 mph on less than 10 gph. Don't know if this is typical. How about some of you guys providing some numbers Richard, you have both the nice 170 and a 180. How about your comments regarding both?