---------------------------------------------------------- RV10-List Digest Archive --- Total Messages Posted Sun 09/19/21: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:15 AM - Using E-10 in IO-540 (Doc) 2. 10:36 AM - Re: Using E-10 in IO-540 (Berck E. Nash) 3. 11:33 AM - Re: Using E-10 in IO-540 (Charlie England) 4. 11:41 AM - Re: Using E-10 in IO-540 (Charlie England) 5. 12:38 PM - Re: G100UL (Thomas Gautier) 6. 01:40 PM - Re: G100UL (Kelly McMullen) 7. 07:12 PM - Re: Using E-10 in IO-540 (Kelly McMullen) ________________________________ Message 1 _____________________________________ Time: 10:15:35 AM PST US From: Doc Subject: RV10-List: Using E-10 in IO-540 Other than deteriorating the mechanical fuel pump parts and perhaps the fuel sensor, (I assume the tank factory sealer is alcohol proof) is there any reason why E-10 could not be burned in the parallel 540 with 8.5 : 1 as all the plumbing is aluminum tubing? Does any one know when mechanical fuel pumps were made alcohol proof? Doc ________________________________ Message 2 _____________________________________ Time: 10:36:13 AM PST US From: "Berck E. Nash" Subject: Re: RV10-List: Using E-10 in IO-540 I'd be really worried about the vapor pressure. I run 91 unleaded with the Peterson STC in my Cherokee 180 and have had a couple instances where the fuel starts boiling in the float bowl on takeoff. Happened on hot days, but the plane was unflyable when it happened. I could make it run with a severely leaned mixture, but only at lower power settings. And that's with ethanol free unleaded. I'd suspect that E-10 is likely to have an even higher vapor pressure than E-0. I now keep one tank with at least half 100LL in it when it's hot out. It's never a problem after takeoff. Obviously things are different with the higher pressures of a fuel injection system, but unless you have a fuel return line you might have problems... On Sun, Sep 19, 2021 at 11:19 AM Doc wrote: > > Other than deteriorating the mechanical fuel pump parts and perhaps the > fuel sensor, (I assume the tank factory sealer is alcohol proof) is > there any reason why E-10 could not be burned in the parallel 540 with > 8.5 : 1 as all the plumbing is aluminum tubing? Does any one know when > mechanical fuel pumps were made alcohol proof? Doc > > ________________________________ Message 3 _____________________________________ Time: 11:33:32 AM PST US Subject: Re: RV10-List: Using E-10 in IO-540 From: Charlie England On 9/19/2021 12:15 PM, Doc wrote: > > Other than deteriorating the mechanical fuel pump parts and perhaps > the fuel sensor, (I assume the tank factory sealer is alcohol proof) > is there any reason why E-10 could not be burned in the parallel 540 > with 8.5 : 1 as all the plumbing is aluminum tubing? Does any one > know when mechanical fuel pumps were made alcohol proof? Doc My conversation with the factory tech was over a decade ago, and he said that the materials had been updated for several years prior to our conversation. He was very open in discussing the matter verbally on the phone at that time, but it was pretty clear (for obvious liability reasons) that it wouldn't be put in writing. I wish I could give you a date, but I don't remember him giving a specific date. He basically said that the change was driven by the fact that the original materials just weren't available any more. Since those pumps are derived from (likely identical to, in some cases) automotive and other ground/water bound engine pumps, my interpretation was that the diaphragm makers had all switched to E-tolerant materials for the much larger ground-bound market. My personal opinion (I'm not a chemist or materials guy) is that there's little risk to aluminum from 10% gasohol as long as water is kept out of the mix. That's based on reading a fair amount of stuff written by people who are supposed to be experts in the field and aren't particularly susceptible to aviation old hangar tales, so are just looking at the chemistry. There's a lot written about the subject if you do an internet search for something like, 'will ethanol attack aluminum', and filter out the random forum posts from people who give 'first hand accounts' without full disclosure of all factors, like a half full tank sitting open to the air for 2 years unused, and then finding corrosion inside. The papers that do talk about aluminum reacting to ethanol seem to be talking about storing near-pure ethanol; not 10% gasohol. There was a 'squadron' of RVs from one of the corn belt states a number of years ago that were flying on something like E-95; near pure ethanol, to promote ethanol use. No idea on what, if anything, they did to protect aluminum tanks/lines. Not sure which fuel sensor would be susceptible. The Floscan flow sensors are used in all sorts of non-flying applications, as are traditional & newer 3wire fuel pressure sensors. FWIW, Charlie -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 4 _____________________________________ Time: 11:41:50 AM PST US Subject: Re: RV10-List: Using E-10 in IO-540 From: Charlie England My one problem was also with a carb'd engine. I agree that it's more difficult, with narrower margins, when running a carb. But remember, the 'vapor pressure' even on the worst gas is around 13psi @100 degrees. So the pressure in an injected engine is way higher than that, all the way to the spider. Individual injector lines have very little pressure, but the mixture lever seems to be able to account for any remaining issues. Electronic injection maintains 40psi+ all the way to the injectors. More and more alt engine guys are running 'dead end' systems, with the regulator behind the firewall and only fuel going into the engine ever sees the hot side of the firewall. All modern cars I'm aware of use dead end fuel systems. Charlie On 9/19/2021 12:35 PM, Berck E. Nash wrote: > I'd be really worried about the vapor pressure. I run 91 unleaded > with the Peterson STC in my Cherokee 180 and have had a couple > instances where the fuel starts boiling in the float bowl on takeoff. > Happened on hot days, but the plane was unflyable when it happened. I > could make it run with a severely leanedmixture, but only at lower > power settings. And that's with ethanol free unleaded. I'd suspect > that E-10 is likely to have an even higher vapor pressure than E-0. I > now keep one tank with at least half 100LL in it when it's hot out. > It's never a problem after takeoff. Obviously things are different > with the higher pressures of a fuel injection system, but unless you > have a fuel return line you might have problems... > > On Sun, Sep 19, 2021 at 11:19 AM Doc > wrote: > > > > > Other than deteriorating the mechanical fuel pump parts and > perhaps the > fuel sensor, (I assume the tank factory sealer is alcohol proof) is > there any reason why E-10 could not be burned in the parallel 540 > with > 8.5 : 1 as all the plumbing is aluminum tubing? Does any one know > when > mechanical fuel pumps were made alcohol proof? Doc > -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 5 _____________________________________ Time: 12:38:43 PM PST US From: Thomas Gautier Subject: Re: RV10-List: G100UL Here is what Lycoming has to say about using gas other than 100LL in IO540s. I think this rev AB version is the latest. Indeed 93AKI, no ethanol, should be fine, with the caveat on vapor pressure https://www.lycoming.com/service-instruction-no-1070-AB Nick Gautier N363TG Sent from my iPad > On Sep 18, 2021, at 11:51 PM, RV10-List Digest Server wrote: > ________________________________ Message 5 _____________________________ ________ > > > Time: 12:45:31 PM PST US > From: Ken Cashwell > Subject: Re: RV10-List: G100UL > > Please clarify. I see folks talking about using 93. I assume those folks a > ren=99t talking about using 93 in an IO540? Right? > > KC > > Sent from KC ________________________________ Message 6 _____________________________________ Time: 01:40:30 PM PST US Subject: Re: RV10-List: G100UL From: Kelly McMullen It will depend on what part of the country you are in. Given the climate, all summer fuel in AZ is required to be 7.0 RVP for emissions, which happens to be the same as avgas. Most areas have summer gas below 8.0 RVP, while winter fuel can go as high as 14-15 RVP. On 9/19/2021 12:38 PM, Thomas Gautier wrote: > Here is what Lycoming has to say about using gas other than 100LL in > IO540s. I think this rev AB version is the latest. Indeed 93AKI, no > ethanol, should be fine, with the caveat on vapor pressure > > https://www.lycoming.com/service-instruction-no-1070-AB > > > Nick Gautier > N363TG > > Sent from my iPad > >> On Sep 18, 2021, at 11:51 PM, RV10-List Digest Server >> wrote: >> >> ________________________________ Message 5 >> _____________________________________ >> >> >> Time: 12:45:31 PM PST US >> From: Ken Cashwell >> Subject: Re: RV10-List: G100UL >> >> Please clarify. I see folks talking about using 93. I assume those >> folks a >> ren=99t talking about using 93 in an IO540? Right? >> >> KC >> >> Sent from KC ________________________________ Message 7 _____________________________________ Time: 07:12:34 PM PST US From: Kelly McMullen Subject: Re: RV10-List: Using E-10 in IO-540 The problem with alcohol is that it absorbs moisture really well. The purest you can buy at the drug store is 91%, because it isn't economical to get the rest of the moisture out. After it sits in your tank, even in Arizona, for a few days it is likely to be down to 70% or less. At those ratios it can start corroding your aluminum. I don't know that proseal is all that alcohol resistant. Mooney puts a sealer over the proseal to protect it but you RV tanks are just straight proseal. Older versions of proseal would soften up a lot when exposed to mogas. I think the current stuff is okay with mogas, but still wouldn't use 91 or 93 pump gas unless it would be consumed in a single flight, within a few days, whether it had alcohol or not. On Sun, Sep 19, 2021 at 10:19 AM Doc wrote: > > Other than deteriorating the mechanical fuel pump parts and perhaps the > fuel sensor, (I assume the tank factory sealer is alcohol proof) is > there any reason why E-10 could not be burned in the parallel 540 with > 8.5 : 1 as all the plumbing is aluminum tubing? Does any one know when > mechanical fuel pumps were made alcohol proof? Doc > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rv10-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RV10-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rv10-list Browse Digests http://www.matronics.com/digest/rv10-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.