MoGas Thoughts

How to keep the Cessna 170 flying and airworthy.

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blueldr
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Re: MoGas Thoughts

Post by blueldr »

Or one could always use the alcohol/fuel tester as is sold by Peterson Aviation with their Mogas STC.

Most all of us will have to agree that leaded fuel is going to have to go. For years now there has been all kinds of controversy about what fuel will be the replacement. At my age, I'm now 91 years old, I doubt that the answer to the replacement product will be settled before I die and I really HATE to miss out on it because I'd just about be willing to bet the bank that it will either the same old Mogas that I've been using for years or a damn close relative that will also work well in your old Model A Ford.
BL
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GAHorn
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Re: MoGas Thoughts

Post by GAHorn »

The majority of "octane boosters" contain ethanol or methanol. You don't want either of them in your airplane unless it's a turbosupercharged Lockheed Connie or one of bluElders old Dizzy-6/7's with take-off water-boost systems.

Gascolators, by design, capture and store small quantities of junk below the inlets/outlets...as a function of debris/water removal so your engine doesn't die from small amounts. The gascolator can, however, become overcome by excessive amounts and one such problem can occur due to alcohol (ehtanol/methanol) which can seperate out in-flight along with water.

juredd1, I suspect your system was contaminated with old fuel and improper additives and water and your recent activity dislodged it from hiding places in the system. Alcohol can dissolve rubber components and attract water (such as condensation which forms along the tank walls due to the chilling effect of flight at altitude of the humid-atmosphere which enters your tank to replace the fuel you're burning)... then you're faced with water...rust...etc etc.

My advice: Quit hurting your system and use ONLY aviation gasoline. There's a reason your system is contaminated.

Quit flying with contaminated fuel unless you'd like to participate in an off-airport landing accident. :wink:
'53 B-model N146YS SN:25713
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juredd1
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Re: MoGas Thoughts

Post by juredd1 »

hilltop170 wrote: The easiest way to test for alcohol in gas is to fill a small container with the gas and drop one drop of food color in the gas and gently agitate it.
Thanks for the info I will give this a try this weekend or before if I can get some time.
gahorn wrote:Quit flying with contaminated fuel unless you'd like to participate in an off-airport landing accident.
I haven't been flying since I come to the realization that I in fact had some issues with an unknown substance in my fuel system.

So even though I have sumped the tanks and drained the gascolators until none of the dark stuff comes out anymore is the consensuses that I still should flush the whole fuel system?

Justin
hilltop170
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Re: MoGas Thoughts

Post by hilltop170 »

You really need to find out what that stuff is so that you can determine what will dissolve it so it will flush out. Trying to wash out water with a hydrocarbon probably won't work, water is not miscible in petroleum. It may not even be water. So try to get some more out and see what will cut it, then make a plan to clean out the system.

I would try to flush each portion of the system out at the closest point available to that portion instead of trying to flush the whole system out thru all the lines, shut-off valve, and gascolator. If the stuff has any gooey, clots, stringy, or solid stuff in it, it could hang up in the valve or maybe restrict the flow without you being able to tell and starve the engine at full power. Don't take any chances, figure out what it is and clean each section independently.

When it comes to cleaning the lines, I would disconnect them at the tanks and flush them both ways. You don't know what might be sticking one direction that might flush out with flow in the other direction.

You can rig up an effective gravity-fed flushing system by hanging a container as high above the plane as possible, filled with whatever solution will cut the contamination (and not hurt the plane at the same time), and connected to the system with large enough hoses to allow good flow (maybe a 5/8" or 3/4" garden hose that itself has been flushed out so you won"t introduce any more contamination into the system). There will not be enough pressure to hurt anything. When flushing thru the lines and selector valve, don't forget to cycle the valve thru all positions and verify proper operation.

Good luck.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
2023 Best Original 170A at Sault Ste. Marie
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
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Greg Bockelman
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Re: MoGas Thoughts

Post by Greg Bockelman »

Aryana wrote:Shell hops on the unleaded avgas bandwagon...time will tell if they actually come out with a product and what it will cost.

http://www.avweb.com/avwebflash/news/Sh ... 070-1.html

In the meantime, I thought this list of airports with mogas was interesting. Doesn't say anything about ethanol though...

http://www.flyunleaded.com/mapusairports.html
You know what they say about assuming. But I would bet money that if they are selling it for aircraft use, they know enough to get "clean" fuel. No ethanol.

But I test everything I put in my plane, mogas wise, regardless.
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