Type of fuel for atomic4

[bcbristoll]

Hey everyone just wondering what type of fuel to use in my atomic4. The downloaded manual I have suggests 90 octane....In our area reg is 87 midrange 89 and premium ~92. I've know that you don't want to use anything with ethanol but just wondering what is the best choice??

[Dave Neptune]

bcbristol, those old rating numbers are far different than todays. The 90 was an leaded regular grade of gasoline good for up to about 8:5 to 1 compression where as the new regular unleaded is good for up to 10:1.

Our A-4's are at 6.5:to 1 so finding a good fast burning fuel is problematic. Your best bet is todays regular unleaded without the ethanol if you can find it. If we could find some 83 rated regular things would be great.

You will make more HP and torque with regular fuel and such low compression. Running premium is a waste of time money and horse power.

Dave Neptune

[Mo]

Shell v-power currently doesn't have ethanol in Canada ( I looked up BC) that's the high octane. Here in NS there's no ethanol in high test either. I have used high test in the A4 since the ethanol came out here in the lower grades...works fine.

[bcbristoll]

Thanks for the info. Just trying to be sure.

[Robs Hubris]

After using regular unleaded for years, I switched to regular leaded (more expensive, sold by marina station here in Michigan). I have noted immediate and lasting improvements in my old A4's performance. Just a happier engine.
best,
rob

[Splash1]

I just came back from Florida where I saw a gas station (Wawa brand) that sold gasoline with no ethanol for boaters only. Thanks to all for the tips.
David Dill
Pearson 30 #319
Middleton RI

[sastanley]

I am in the mid-Atlantic area and there are several retailers that sell NO-Ethanol fuel. Some are roadside and some are water based.

I've found https://www.pure-gas.org/ to be an excellent resource.

[Boat]

Shilshole Marina here in Seattle has non ethanol regular. i think its 89 octane

[joe_db]

I used to fill my tank with 100 octane no-ethanol avgas for the winter. It does not absorb water, but other than that the engine ran the same as ever and I decided some fuel treatment was cheaper and easier anyway.

[ndutton]

Joe, I just read an anecdote about an experimental aircraft that used ethanol blend and experienced engine failure purportedly due to water absorption in the fuel. Suddenly the report disappeared as I was about to ask a barrage of questions about it.

[joe_db]

Joe, I just read an anecdote about an experimental aircraft that used ethanol blend and experienced engine failure purportedly due to water absorption in the fuel. Suddenly the report disappeared as I was about to ask a barrage of questions about it.

Didn't want to creep the thread - but here goes.
I told them it was a bad idea. The aircraft fuel system has a water separator and just like ours, it only works if the water will separate They went back to avgas after that or ethanol free fuel, which is the only auto fuel approved for (some) aircraft.

[ndutton]

I'd be interested in knowing what testing connected this engine's failure to ethanol caused water absorption. If that were actually the cause, where did the water come from because it must have been a helluva lot.

What is different between the low compression engine in your anecdote and ours? My engine has been on a steady diet of E10 for at least 13 years and doubtless many more prior to my ownership without a single issue that was attributed to fuel contamination. Considering it has lived its entire life in the marine environment (the highest humidity), how can this possibly be? 1% MMO is the only additive I've ever used.

[joe_db]

I'd be interested in knowing what testing connected this engine's failure to ethanol caused water absorption. If that were actually the cause, where did the water come from because it must have been a helluva lot.

What is different between the low compression engine in your anecdote and ours? My engine has been on a steady diet of E10 for at least 13 years and doubtless many more prior to my ownership without a single issue that was attributed to fuel contamination. Considering it has lived its entire life in the marine environment (the highest humidity), how can this possibly be? 1% MMO is the only additive I've ever used.

I have got an *entire quart* of water out of an airplane that sat through a few thunderstorms on the ramp in North Eleuthera. Draining fuel and checking for water is a routine preflight activity. Between old fuel cap gaskets that are not perfect, sitting through numerous temperature changes, and flying through rain at 150 knots, water can get in there. Most planes have at least 3 drain points and after Cessna got sued over a water contamination fatal accident, some of their airplanes have around 11 drains!
A lot of water indicates time to buy new fuel cap gaskets, but even with good ones it was not unusual to get a few drops of water in a plane I had flown the night before. Water can also freeze in fuel lines. A buddy of mine had an engine failure for just that reason and now his model aircraft have drains at a low point that did not have drains before. No one realized there was a gentle slope back up to the water separator from a few feet back and that was enough to trap enough water to freeze.

http://download.aopa.org/epilot/2010/100730cessnasaib.pdf?_ga=2.17742269.50124715.1529585724-95703034.1529585724

[ndutton]

Thanks Joe. That speaks to the practice I've applied all along about keeping water out in the first place rather than counting on filtration to manage it. I always felt filtration was the last line of defense, not the entire defense.

My fill plate O-ring is replaced bi-annually as regular maintenance, my fuel is carried via jerry jug to the boat from a high volume gas station, (a practice in clear violation of marina rules). In fact, I'm topping off a tank tonight under cover of darkness. Getting caught risks eviction but it's a risk I choose to take to avoid fuel dock swill.

I read nothing in your posts or the link you provided that positively connects this particular experimental aircraft's engine failure to ethanol or said another way, that ethanol caused the failure. However, digging deeper by researching an FAA SAIB referenced in the link I did find the treatment by the FAA prohibiting ethanol blends in piston powered aircraft:

https://www.daec.de/fileadmin/user_upload/files/2012/fachbereiche/luftfahrttechnik/CE-07-06.pdf