800' strip - Maule/Cessna 180/Stinson?

[maules.com]

Jimbabwe, cooling issues are not a big problem provided the baffling and cooling lip are properly installed. The 260hp runs a bit hotter than the 235hp
The O540 B4B5 is the only 235 engine on Maules certified for mogas.
It runs at 2575rpm max versus 2400rpm max for the other 235hp engines thus it cannot utilize the long 86" 2 blade prop, (noise).
At 2575 versus 2400rpm there is 175rpm more wear on the B4B5. So one would expect lower tt usage of the engine, though compression is lower.
Because of the deeper cowling drag O540 Maules are a couple mph slower than IO540 Maules.
Fuel savings over 100 hours assuming you ran 50% time on mogas and 50% on avgas because of mogas availability when traveling is aprox $326.00/100hrs.
Cost of STC plus fitting of pumps and fuel cooling shrouds aprox $3250.00

[Jimbabwe]

Thanks, Jeremy.

From what I gather from some of your other posts, the 80" 3-blade prop is the quietest. Am I correct?

I'm not concerned with maximum climb performance or top speed. I need to get off the ground as quickly as possible and as quietly as possible.

I'm actively looking for a plane to buy now. Find me one? Must have complete logs.

I'm going to stay away from the IO because I will be having lots of restarts shortly after a shutdown, and it will be in hot conditions (Sacramento)

There seem to be so many variants of the O-540 in the M-5, M-6 and M-7, I can't make heads or tails of them. If I don't plan on using mogas, should I go with lower compression and a higher RPM limit, or higher compression and a lower RPM limit? Hmm...

I've downloaded the TCDS and can see which engines go on which Maule as well as which props go on which Maule.

Now, the questions which remain for me: Which Maule/engine/prop combination is best for: takeoff from an 800 foot strip, a 15-minute flight, a shutdown for a few minutes, a restart and a 15-minute flight back to the 800 foot strip?

[maules.com]

The IO540 lycoming is quite different from an injected Continental.
Lycoming uses a pressure carburetor and hot starts especially after a short down time are not as big an issue.
Engines used are
O540 J1A5D 2400rpm 235hp single drive dual mag
O540 J3A5 2400rpm 235hp
O540 B4B5 2575rpm 235hp low compression
IO540 W1A5D 2400rpm 235hp single drive dual mag
IO540 W1A5 2400rpm 235hp
IO540 V4A5 2700rpm 260hp

The 3 blade 80" prop is the quietest and is same cruise speed as others especially if dragging floats, but is a tad heavier.
Lowest performer is the old 78" 2 blade Hartzell prop.
Best performing props are 86" 2 blade (not on B4B5) and 80" 3 blade.

M5, M6, MX7, M8 share same cabin size. M7 is larger in rear.
There are 8 different wing configurations.
The shorter the wing, the faster cruise, but lesser lift.

All is a compromise. Gain here, lose there.

[Jimbabwe]

Thanks a lot, Jeremy.

Now, to find the plane!

[Mountain Doctor]

Wow Doc!! No offense meant, but I think you'd be amazed what spending of maybe $10K - $12K in proper places would do for your performance!! No Joke! Or are you really flying a C150/C172? (JOKING!!)

Nope. It's a stock well cared for and frequently flown Maule. My skills are appropiate as well. It's just a bit neutered.

I note that years ago Maule dropped my model from the lineup, as well as the 160's. I suspect the reason is inadequate performance and non-Mauleness...

IIRC the upgrade to a C/S prop was a $20,000 difference (I bought the plane new). At the time I did not think it was worth the money.

If I had to do it all over again I would have bought a used 235 or 260 rather than a new 180. Or a used 182 but the Cessnas are so much more money for what you get.

I feel that I got what I paid for, so I'm not complaining, but not all Maules are STOL.

[andy]

You mentioned the mogas STC. I had heard that there might be some performance decrease with it, but I found this article on AVWeb and it's a pretty good discussion of the pros and cons. From a practical viewpoint it seems to me that the most difficult obstacle is the availability of high quality mogas without ethanol. Most airports don't have it and around here there are very few filling stations that have E0 gasoline. Even if there was a way to get it at a filling station, I would worry about fuel quality if the station was an off-brand. I would also worry about vapor lock and detonation in my engine. Mogas also deteriorates faster than AVGAS while sitting in a tank unused. All of these cautionary factors would make me hesitate to use mogas in an engine equipped with the STC - especially on a hot day at a high 800' airstrip with a heavily loaded airplane. You can burn 100LL in an engine with the mogas STC according to Peterson Aviation but it eliminates the benefit of having the STC.

The one situation where I can definitely see the benefits of using mogas are with a seaplane. Most boat marinas around here sell E0 89 or 93 octane fuel to prevent knocking in higher performance engines. I think that's true of boat marinas around the country. So if you put straight floats on your airplane, the mogas STC would allow you to fuel at a larger network of boat marinas and would take a lot of the restrictions out of cross-country travel in an airplane with straight floats. It would still be a really good idea to call ahead and make sure the marina has E0, though.

[TomD]

Most boat marinas around here sell E0 89 or 93 octane fuel

Now we would not want you to get crosswise with the local taxman since Boatgas usually does not carry the highway or aviation tax other gasolines do. I know in Canada it is colored bright red. Which explains the red "racing stripes" on so many floatplanes up there.

From the Lycoming Operator's Manual:

O-540 B series 80/87 octane minimum (7.2:1 compression ratio)

All other 540 engines listed as available on Maules 100/100LL Minimum (8.5:1 compression ratio)

TD

[Jimbabwe]

Andy, good point about the mogas. Besides the facts that I really don't like the smell of mogas and I really DO like the smell of 100LL and its exhaust, I think mogas won't really benefit me. Gonna remove that criterion from my search.

[sbmaule]

Jim,

Just came across this post. hows your search coming along?
Be happy to visit your strip and take you for a ride in a maule.

2005 M7 235 (we spoke via phone a few weeks ago) I have it listed for sale.

A consideration: 800' generally is no problem, I fly out of 400' at sea level. but for commuting on a regular basis (think that was your mission) need to have a flexible job or understanding boss, wind/weather could play a roll getting in and out if youre on a schedule regardless of what youre flying.

Let me know

Doug

[Jimbabwe]

Doug,

Check your PMs.

Jim

[John Ashcroft]

If it were me, I would go for the most horsepower possible. M5235 will leap off 800' and land fine also.
Horsepower is your friend.