G

gmpaul

Active Member
I'm building an RV9 and starting to look for an engine. Here's the Question: How does the RV community feel about 100LL? Do ya'll think it is here to stay or is it going the way of ethel for our cars?

Thanks GP
 
100ll

Mr. GP,
In our group, we operate as many as 8 different ACs with mogas. In all cases, they have exibited lower fuel consumption, lower oil consumption, and vast increase in plug life. Engines include, Continentals, Lycomings, Rotax, Corvair.
In one case, the Conti powered 182 is equiped with an engine anylizer. With 100 LL, temperatures are unstable and varyiing as much as 150 deg and up, with mogas, temps stable in the 10s up or down. Some of these ACs have been running on mogas for more than 20 years, most on the average of 10 years.
The engines most sensitive, and for the worst. are the Rotax, and the Corvair.
T88
 
My guess

My guess is it will be around as long as it is not legislated out. It is too easy a market to be ignored even though you hear it is such a small part of the market ... it remains a significant amount of money that exclusive sales to make someone very rich. It's a free enterprise thing.

Bob Axsom
 
The article in "24 years of the RVator" is a very strong argument in support of MOGAS.

It confirms those facts stated by T88.

Cooler operation, less fouling and of course... less MONEY!

The planes with lower compression should be able to use it without any problems, so long as you don't get pre-ignition.

One problem is, you don't get that great AVGAS smell!

I first told myself that I would never use MOGAS in my plane but, I may just reconsider. Especially with fuel costs going up and up!

The IO-390 is a moderate compression (I think 8.7:1 ?) engine and *should* work adequately on MOGAS.

;) CJ
 
100 LL will be here for some time, IMO.

First, there is a market for it.

Second, there are at least a handful of general aviation engines that depend on it.

Third, there are plenty of aircraft that don't have autogas STC's at this time. Without 100 LL they would be grounded.

Fourth, most FBO's don't want to carry two different fuels - the 100LL for the aircraft that need it and autogas for everyone else, so they are going to default to 100LL so they can serve everyone.

Fifth, avgas (and its lead content) is a pretty small target for the environmental crowd. They have bigger fish to fry and will <probably> concentrate their efforts in areas with what they believe to be a bigger benefit.
 
100ll

A few interesting facts. If any one has the opportunity to look at an old flight manual of a Cub, for example, you would find the following. Fuel of choice, pump gas, AV gas optional. Oil of choice based on SAE specification, no mention of AD oil.
The market for AV gas is based on the fact that it is mandated for most ACs. Unfortunately, aviation is riddled with heresay, and lack of motivation. The EAA was the spear head for approval of mogas, yet there are many, particularly in the experimental community, that for some odd reason do not recognize the benifits of mogas.
If we ever see the Continental /Honda or the Bombardier/Rotax, these new engines will accept mogas, av gas, and even for the mix affecionados, a mixture of the good stuff mogas, and the foul stuff,AV gas. Regardless, mogas is king, despite all the "claims" of alcahol ethonal, MTBE, etc.
How can I make these claims, simple, from racing experience, and 2 years on a dynomometer. A stock racer, who lived on my old field, even stopped using AV gas for his race cars. Mogas was better, among other "idiocincracies" was the fouling caused by the lead.
Lead is/was the easiest and most convinient means of controlling detonation, octane's purpose in life. High or low octane, gasoline is the same. Resistance to pre ignite is a function of lead or any other chemical that has that ability. Higher octane is no more powerful than low octane. The high stuff simply resists pre ignition.
Compression ratios has little to do nowadays, with the use of higher octane numbers. A look at the auto world will bear that out. Some will say, it's because of computers. Well then, why isn't aviation embracing technology that has been present now for more than 35 years, which is the root cause of the use of AV gas, and the problems it brings with it.
Do I believe in mogas, you bet.
My RV10 will be fitted with LASAR, and will use mogas as much as possible. Yes, Unison says not to, and because it was mandated by the FAA (our biggest problem). I tried mogas on my LASAR equiped Arrow, and the results were short of amazing. We're experimental, so go for it.
T88
 
reducing 100LL usage

Not using 100LL is a very good thing, IMHO. Reducing the amount of lead that we spray across the countryside is simply the neighborly thing to do.
 
Mogas

I would love to use strictly MOGAS.

Can those of you that use it can comment on how difficult it is to get on X/C's and how you handle mix and matching MOGAS with 100LL? I would be interested in some real world experiences. Also, how do you keep your cars from smelling after hauling 20-30 gal of MOGAS in your cars. I have a hard enough time with the 2.5gal jugs for the lawnmower. Do any of the airports you hit on X/C's give you a crew car and some fuel jugs to borrow? Is this a dream or realistic?
 
X/Cs

We use the 182 for X/C and average 12 gph with mogas (87). Most trips under 4 hrs we'll go back and forth. 4 hrs. gives us a broad safety margin. Never had the experience of having to fill with mogas on a trip, nor ask to get some, so we do the dasterdly deed to the engine, and fill with AV gas. The 182 feeds both tanks at once, though I personally like one at a time. We found that if AV gas is less that 1/4 (approx) of the exiting mogas, fuel consumption increases little. with more than half, consumption rises at or above 14 gph. In addition EGTs are unstable. The added fuel consumption is largely due to adding fuel for cooling. As to harming the engine. av gas is rarely used for more than a couple of hours. Refilling with mogas, stabilizes temperatures, and when fully stable, it's clear enough that the build ups in the combustion chamber have been minimized. This has been our experience.
T88
 
Hi Guys,

I am building with mogas in mind, will still be 2-3 years before I'm flying. Consideration needs to be given to vapour lock.

If I don't like it I can always revert back to old 100LL.
If 100LL goes then at least I know I built with mogas in mind.

So I think I have both bases covered.

Regards
Rudi
 
Vapor lock

When EAA was in the midst of testing, a special "brew" of fuel was tested in order to address this problem. The "brew" had a rapid vapor number just for this reason/. The C150 labored (as they always do) pass oxygen altitude, with no ill effect. Pikes Peak is 14,700' MSL and all sorts of cars climb up there. My one visit did not reveal vapor lock problems, and cars seemed to be quite willing to make the climb. Oxegen was available for people though.
FYI, the Rotax 4 cycle AC engines are recommended to run mogas, and operating altitude for the little guys is 20K. I firmly believe that the vapor lock issue, is an aviation old wives tale, and that nearly all cases are induced by improper installations, poor equipment, and practices, any or all of the above. We've been up to 10K with the vaporlock king a C182, and Big Bertha never so much as weezed. The only time she balks is when we are forced to add AV gas.
BTW, we see more vapor locks on various fields and nearly all are using AV gas.
Ain't no big thing.
T88
 
XP-360 approved for Mogas

The Superior XP-360 and its FAA Certified twin, the Vantage engnie, are approved by the manufacturer for 91 UL Mogas and 100 LL or 91/98 Avgas.

Dave Cole
RV-7 Wings
 
Three Years From Now

Mogas is lovely stuff. Been using it for thousands of hours.

About refueling away from home: In years past, I carried jugs of mogas to feed a 172 (cheap was a factor, too) halfway through the trip, refilling empties via rental car at the destination. You could get some interesting looks carrying jugs through the FBO and refueling on the line, but at most smaller fields (5,000 feet of runway seems to be the dividing line), you are allowed to drive up to your aircraft, and nobody really gives a Rhett Butler. If you do carry gas, fill the containers, leaving very little airspace, otherwise they fart gas vapor as you climb, making for a stinky ride. If deadheading empties, leave the cap off; residual fuel will evaporate soon enough, and the farting issue is obviated. And if you think I'M nuts, there's a lot of nuts flying the backcountry. An upside is that the smoke column makes SAR's job easy. :p Unfortunately, RV's can't carry the load, nor are they as easy to load as a Cessna.

But real dangar lurks. The corn lobby convinced our know-nothings in D.C. to require alcohol in mogas in a few years. Already, CA fuels are poisoned with the stuff. It's coming nationwide, like it or not. Therefore, every component of your fuel system should be alcohol tolerant. Find out what materials manufacturers use - ask about those O-rings. Soft material disintegration I do fear; alcohol's water affinity and potential for ice particle precipitation after rapid climb is not on my worry list (water alone isn't a good fuel, either), nor is the lower vapor pressure. They are, though, considerations. How about we each contact EAA and Peterson, asking them to reinvestigate using alcohol laced fuels, every time one of these 100LL/mogas threads get started? It's the way of the future.

John Siebold
 
My xp360 was built using standard compression pistons. This was superiors advice. They said that this will enable me to run mogas if i want/need to.
Im happy with the choice I made.
Also I second the save the enviro with lead free fuel. Any bit we do will help our planet.
 
Lead

I'm not an enviromentalist per se, but I see no reason to use lead to control octane. Leads affect to the enviroment is that more of it is required to make our birds fly. I tried Mogas in my old Arrow equipped with LASAR. Fuel consumption droped from 1.5 to 2 gph on 1ooLL. with mogas, it dropped another 1 gph or up to 3. Less fuel burned to make the same power in speed is indeed good for the enviroment. the use of LASAR with it's timing map tailored for Lycoming help considerable as well. Plug life alone it proof that all the gas that is burned is completely utilized to make power.
On the subject of alcahol (actually ethenol) it has little if any effect on performance save for a very slight increase in consumption and hardly noticable. When reaching more than 15%. it can begin to affect some components. It's amazing that the auto world has long addressed this issue. As homebuilders we have that choice.
In Brazil with their abundance of crops to make alcahol (actually ethenol,) autos are now available to run either straight alki, mogas or both. With the alky costing them about 50C/ gal vs nearly $6 for petrol, it's a no brainer for Brazilians. These auto, and many made stateside, have these features.
Alcahol powerd race cars do make more power than the gasoline brothers, but for a price. Alky require a 10:1 or so ratio rather than 14.7:1 for gas. There is also the lubricity issue, straight alky has none, but that's racing.
It's amazing that the after marker engines are approved by their makers to run other than AV gas, while the certified stuff has Big Brother to "protect" us from the mogas baddies.
T88
 
I was always under the impression that in order to run mogas, the engine's compression had to be 7.50:1 or lower. It appears that it is meerly a myth? I'm planning for my RV-7 to drink mogas. Is there some kind of guideline as far as compression is concerned? I was afraid that I wouldn't be able to run the 160 HP Lyc 320. From what I read here folks are running it in their higher compression engines as well. This is good news for me!
 
Mogas

It is a myth. Kawasaki motorcycle 250cc 12.5:1 compression, fuel used "87 "octane. Chevrolet Corvette 10.5:1, and the list is long of engines in motorcycles and autos that have well above 8;1 ratios.
Illegally, I tried 91 octane mogas in my Arrow 8.5:1 and equiped with LASAR and it worked very well. Added smoothness, decreased fuel flow, and due to turbulance, could not truly get a handle on speed, but it favored the higher numbers.
Ain't nothin' to be 'fraid of.
 
OK, I'll ask....

I have owned airplanes now for 25 years or so - just a couple, a Grumman AA1B with a high-compression O-320 (160 HP), and a J-3 with a C-65. Of course, I now have the RV-8 with a 180 HP O-360 (carburated). Both the Grumman and Cub were certified, and I always tried to operate them to the letter of the law, which means the Grumman got 100LL (there were no STC's for the engine/airframe combination) and the J-3 got MoGas because today's "Regular" has a lot better octane than that specified in the manual.

Now that I have entered the experimental world, I have the option of running Mogas as I wish. My engine manufacturer, although recomending AvGas, said that it will run fine on Mogas should I need to do that. My biggest concern has never been vapor lock (as many have said), but the affects of Mogas chemistry on seals and other soft stuff in the fuel system. Which leads to my question...

If I trace the RV-8 fuel system from tank to engine, I find lots of metal-to-metal joints, potentially some seals in the Andair fuel valve, some jacketed hose between the gascolator and fuel pump (and Carb), soft-goods in the fuel pump, and then I suppose, some seals in the carb. Does anyone have any test data (i.e. FACTS) about what components are likely to suffer damage from Mogas with alchohol, and if there are replacement parts available for those parts which are "fuel-proof"? In other words, if I want to make my system stand up to Mogas, what should I replace to MAKE SURE that I don't end up with a problem?

I like being in experimental aviation, but I am pretty conservative when it comes to things that can leave me powerless at a bad time...I know many folks have run Mogas for a long time, and I respect that experience - I am just looking for answers other than "just do it!"

I suppose this might spark some discussion... :rolleyes:

Paul
 
Ironflight said:
My biggest concern has never been vapor lock (as many have said), but the affects of Mogas chemistry on seals and other soft stuff in the fuel system. Which leads to my question...

If I trace the RV-8 fuel system from tank to engine, I find lots of metal-to-metal joints, potentially some seals in the Andair fuel valve, some jacketed hose between the gascolator and fuel pump (and Carb), soft-goods in the fuel pump, and then I suppose, some seals in the carb.
Click to expand...

Paul, GREAT point!

Now this is what I have *heard*. There could be more myth, lore and wive's tales floating about.

Reason being, it is the ALCOLHOL CONTENT in the stuff dispensed at service stations that will presumably eat away at the seals. The rumor is that the MOGAS at the fuel dock is either lower in content or devoid of the alcohol.

The alcohol content WILL screw with our capacitive senders, though! The variable dielectric (inconsistent alcohol content in the fuel) will affect the way the gauge reads!

Of course, we are professional pilots and we don't need no stinkin' GAUGES!

NOW, we can test for alcohol content and learn if there truly is a difference in products and where they are sold (and how much they cost!This could put some of the myth to rest.

The wire guy from Kitplanes Magazine (Dan, can you hook us up with his addy) made a test jar with capacitor probes designed exclusively for testing alcohol content in our fuel!

It is a technical little read, but if a few of us around the country whipped one of these up, we could do a widespread and random testing of fuels available!

:D CJ
 
Alcahol

More myth than truth, is correct. There was a time in aviation when POH specified mogas, and AV was optional. Little did they know back then that lead did lots of harm to engines, rather that lubricating anything as is professed in the aviation community, and only in the aviation community. At one time Lycoming was anti multigrade oil, now it's their first choice.
Capacity sensors, at least by one manufacturer, Westach to be exact, use "water" for the purpose of adjusting levels.
As to alcahol, actually ethenol, on this subject, the auto industry has to be given far more consideration that the AV community. After all, that industry is equally vulnerable to lawsuits as is the AV industry.
Alky.aka ethenol, does indeed cause some malidies, but on long term basis, very long term. If one flies a hangar queen about 2 hrs per year, it "may" cause problem. The auto world has corrected this, aviation is still on the heresay level.
Minnissota, and another state have the highest ethenol contents in gasoline, and according to the automotive industry, quoting from my Chrysler's "POH", 2002 vintage, it says that due to the high content of ethenol (alky), some component will require more frequent attention, and "possible" replacement. That was 2002. This had since been fixed.
The old wives tales about mogas have never been more prevelent since the time unleaded fuel was introduced, yet in the case of autos, they now last longer than ever before. Why dat be?
Cheers, and due to the "Christmas" (no PC for me) holdays so close at hand, my warmest gretting to all.
T88
 
No more mogas for me

I've been following this thread for a bit now and it's time for my $.02. I'm not an engineer nor do I play one on TV. I have a '59 C172 with a Conti O-300 that's STC'd for auto gas. I've got almost 700 hours on it since I've owned it. I ran 87 UNL for about 3-1/2 years and in that time the fuel valve had to be rebuilt due to leaking , the primer had to have a new seal installed and I had a couple precautionary landings due to partial fuel starvation because of some "unidentified foreign matter" that clogged up the fuel inlet screen on my carb. We spent a number of hours taking fuel samples from the sumps in the wing tanks and gascolator and eventually purged all the garbage from the tanks and only by going back to 100LL were we able to get good, clear, consistent fuel samples every time. Was there ethanol in my mogas? Probably. Did I test for alcohol content? No. Was it responsible for my problems? Don't know. Is mogas as consistently monitored by the producers to be a known quality as is 100LL? Like I said, I'm not an engineer, but I've heard that the answer to that would be not just no, but hell no! My base airport, P04 still has 100LL for under $3./gal. For me, I'll stick to the known commodity, thank you. And the O-360 going in my RV will get the same.

--hawk
RV-7A(FWF & panel)
N728E reserved
 
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NOW, we can test for alcohol content and learn if there truly is a difference in products and where they are sold (and how much they cost!This could put some of the myth to rest.

The wire guy from Kitplanes Magazine (Dan, can you hook us up with his addy) made a test jar with capacitor probes designed exclusively for testing alcohol content in our fuel!

It is a technical little read, but if a few of us around the country whipped one of these up, we could do a widespread and random testing of fuels available!

:D CJ[/QUOTE]

An easier test for ethanol in the fuel is to use a $2.95 rain gauge from wal mart or one of those old plastic fuel sump/screw driver gizmos we check for water in our sumps with.

Put about 1/2"-3/4" of water in the bottom of it and mark the level. Add the fuel to be tested leaving enough room in the top 1" to be able to cap it with your thumb and shake the sh#t out of it.

The ethanol will dissolve in the water and it will look like there is more water than you originally put in if ethanol is present. The difference will be clear, obvious and significant. If the water level is the same as you put in the gas has no ethanol.

I have an IO 540 that had been run on a mixture of MoGas and 100LL before I got it.

The inlet microscreen varnished over and damn near killed me when the engine stopped at a most inopportune time. This occurred at around 180hrs.

I would not let that stop me from using MoGas if I wanted to. I would, however, suggest if using MoGas frequently cleaning and changing of any micro filters.
 
OK, Good discussion items....

As far as alchohol in the Mogas, to me it seems as if testing is a mute point. Since the use of it in auto gas is hard to predict, and testing is problematic, I think that if you want to run it regularly, you simply have to ASSUME that it will have alcohol in it, and protect your system appropriately. (You arrive at an airport low on fuel, and have to fill up. You go through the magic test, and find alcohol - what do you do? Sell the airplane where it is and take the bus? Of course not- you fill up and go anyway!)

So my question remains - if I want to "Auto-Gas-Proof" my system, what parts need to be replaced, how do I make sure they are the right (fuel-proof) material, and is there any downside to installign them, and using them with AvGas?

The famous Peterson STC doesn't answer these quesitons becasue it requires you to use AutoGas without Alcohol....

Paul
 
More Digging

Some thoughts about the foregoing posts:

The concentration and dwell time of alcohol on susceptible materials makes a difference. My foggy memory says that somewhere, maybe it was EAA (lots of background info on their web site), said that <5% alky was tolerable long term. Fill and go, but I would purge or dilute the remaining alcohol laced contents after arrival (and run the engine some). Alky proof is best of all.

I'm not surprised that a 46 year old Cessna had fuel leaks. Mine did too, fuel valve included, when it was only 20 years old, and back then materials now used in the auto world as alcohol-proof didn't even exist, nor was there any need. With the FAA making improvement cost-prohibitive, I'll bet nothing much has changed internally since parts like Lycoming fuel pumps were first certified, back when only bootleggers were distilling alcohol from corn. Dats why tis so.

Yes, every element of the fuel system has to be considered; you might want written confirmation from the manufacturers; at least obtain specs, but Acme Manufacturing isn't going to bother telling you of future changes. I have a tank sealant sample ready to dunk if I ever can bring myself to buying a gallon of the alky-laced stuff at the local Stinker Station. Stewart Warner says their floats and senders Van's sells are alcohol-proof. Take it from there.

That known commodity, Avgas? Chevron gave me (and a whole bunch of other people) a new engine because of Jet-A contamination of 100LL. An identical issue grounded Oz for awhile. It's a risky thing stepping out of your front door.

John Siebold
 
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So my question remains - if I want to "Auto-Gas-Proof" my system, what parts need to be replaced, how do I make sure they are the right (fuel-proof) material, and is there any downside to installign them, and using them with AvGas?
Click to expand...

Twin Cessnas spefically the Turbo 310s and 414s have a propensity to form ice in the fuel distribution spiders ar high altitude during the winter.

It is Continentals recomendation that isopropyl alcohol be added to the fuel during winter months to "absorb" the moisture and lower the freezing point.

I believe the recommendation was a pint per 25-50 gallons. They make no mention of replacing seals or hoses. In fact I did this gor many years on my 685 Commander and 414 Cessna with no deleterious effects. So I suspect the answer is nothing necessary to change prior to using MoGas with alcohol.
I have heard many concerns about the effects of alcohol on non metallic components but have never heard it 1st hand nor seen it. OWTs????


More problematic to running MoGas is it's availability at airports.
 
Wrong place for facts

Ironflight said:
As far as alchohol in the Mogas, to me it seems as if testing is a mute point. Since the use of it in auto gas is hard to predict, and testing is problematic, I think that if you want to run it regularly, you simply have to ASSUME that it will have alcohol in it, and protect your system appropriately. (You arrive at an airport low on fuel, and have to fill up. You go through the magic test, and find alcohol - what do you do? Sell the airplane where it is and take the bus? Of course not- you fill up and go anyway!)

So my question remains - if I want to "Auto-Gas-Proof" my system, what parts need to be replaced, how do I make sure they are the right (fuel-proof) material, and is there any downside to installign them, and using them with AvGas?

The famous Peterson STC doesn't answer these quesitons becasue it requires you to use AutoGas without Alcohol....

Paul
Click to expand...

Paul,

Not sure how long you've been following Doug Reeve's VAF Forums(and the predecessor YahooGroups). Both have long been good places to get information from people that you would eventually meet at fly-ins. Unfortunately, this forum is slowly decaying. Self-professed experts(who don't give us their real names) fillibuster with a know-it-all, brow-beating, shout-em-down style that drives away many Rvators. Many "legends" of Rvation don't post here anymore. A sad loss. :(

To find out more about alcohol, seals, performance, and the like, try a web search on "ethanol" AND "aviation", "E-85" AND "aviation", etc.

Beware the anonymous experts.
 
N395V said:
Twin Cessnas spefically the Turbo 310s and 414s have a propensity to form ice in the fuel distribution spiders ar high altitude during the winter.

It is Continentals recomendation that isopropyl alcohol be added to the fuel during winter months to "absorb" the moisture and lower the freezing point.

I believe the recommendation was a pint per 25-50 gallons. They make no mention of replacing seals or hoses. In fact I did this gor many years on my 685 Commander and 414 Cessna with no deleterious effects. So I suspect the answer is nothing necessary to change prior to using MoGas with alcohol.
I have heard many concerns about the effects of alcohol on non metallic components but have never heard it 1st hand nor seen it. OWTs????


More problematic to running MoGas is it's availability at airports.
Click to expand...

This is an interesting thread. I can see where 1 pint per 25-50 gallons would probably not be a big issue. However most auto gas here in Iowa has 10% ethanol in it. That would mean 5 gallon per 50 gallons of gas. I just passed my old truck off to my son with 200,000 miles on it and the ethanol didn't seem to hurt it any. But as mentioned earlier in this thread the auto mfg's have addressed the issue over the last few years.

Keep the comments coming, someday I may need an engine and have to decide what to burn for fuel. :eek:
 
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Hi Guys,

Yes be aware of the self protest experts, read and research and make up your own mind.

Vapour lock is an issue on RV's, Read 24 years of RVator, (someone point it out to me). Mogas is more prone to vapour lock. I consider it worthwile to address before running mogas, that is why I am building with that in mind.

Alcohol is another.. quoted from the XP-360 web site:
NOTE: Use of auto fuel blended with ethanol or gasohol is forbidden. Ethanol (alcohol) mixed with unleaded fuel can cause vapor lock, carburetor ice, reduction in range, carburetor problems and damage to the fuel system. The use of an alcohol (and water) tester is recommended .
Click to expand...

I wonder why they say this, I shoot of an email to them and try and understand what specificly they are refering to with 'damage to fuel system'. The rest I understand.

Kind Regards
Rudi
 
HI Guys,

I have send my email to XP-360 to ask about the damage to fuel system, and also the fuel companies that say their fuel with alcohol is waranted in any engine, This is XP-360's response...

I understand that Rudi has 2 primary questions which are addressed here.
Please let me know if you need additional information.

1.) Alcohol effects on fuel system components:
Superior's XP-360 engines are manufactured with components that are resistant to alcohol. However, fuel system components industry-wide have not all historically shared this feature. Because the XP-360 engine is an experimental engine and can potentially be modified by the user, the potential exists for fuel system components to be used which are capable of being damaged by alcohol. Further, seals and other components in the airframe fuel system may not be
tolerant of alcohol.

2.) Statement from fuel companies regarding the use of alcohol in gasoline:
Superior does not allow the use of fuel containing alcohol in its XP-360 engines. Superior strongly recommends the use of a Reid Vapor Pressure tester such as a Hodges Volatility Tester when motor gasoline is used.
Click to expand...
Looks like they stand, no alchohol in their engines...it is a pitty, since most Mogas in SA has alchohol in it.
 
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alcohol

Rudi said:
Looks like they stand, no alchohol in their engines...it is a pitty, since most Mogas in SA has alchohol in it.
Click to expand...
Not exactly what I understood them to say.
Superior said:
Superior's XP-360 engines are manufactured with components that are resistant to alcohol.
Click to expand...
Seems like their engines are ok with alcohol content. They seem to be more worried about other parts of the fuel system having trouble with alcohol in the fuel.

In any case, you can put anything you want to in there - it's your engine, and it's your butt.

What's surprising and disappointing to me is that there seems to be no push to have good quality aviation fuel with no lead in it. I'd be happy to pay a premium over standard mogas for high-quality aviation fuel without lead.
 
Article on 100LL alternative

Ironflight said:
As far as alchohol in the Mogas, to me it seems as if testing is a mute point. Since the use of it in auto gas is hard to predict, and testing is problematic, I think that if you want to run it regularly, you simply have to ASSUME that it will have alcohol in it, and protect your system appropriately. (You arrive at an airport low on fuel, and have to fill up. You go through the magic test, and find alcohol - what do you do? Sell the airplane where it is and take the bus? Of course not- you fill up and go anyway!)

So my question remains - if I want to "Auto-Gas-Proof" my system, what parts need to be replaced, how do I make sure they are the right (fuel-proof) material, and is there any downside to installign them, and using them with AvGas?

The famous Peterson STC doesn't answer these quesitons becasue it requires you to use AutoGas without Alcohol....

Paul
Click to expand...
Here is an article from AVWEB Pelican's Perch on alternatives to leaded fuel.
Lead in the hogwash
I'm not endorsing this, only throwing it out for hashing over.

Also, there are some Rvators in S.Dakota that have been using ethanol for years. Met one at LOE'05 and saw three or four matching RV4's at Osh'04 that burn ethanol. Anyone have the scoop on that?
 
is an STC needed for a C65 engine?

While I am building my RV8A I get my flying "fix" with my 1942 Taylorcraft L2 which has a Cont 65 engine. This thread has made me think of using Mogas in the L2. By coincidence, I was annoyed today by the fact that the FBO where I normally refuel was closed so I had to fly to another for AVgas.

Do I need an STC on a Cont 65 engine or can I just use it?

Paul, you have owned a cub, probably in the vintage and with the same engine as my L2, so you may have some insight as to this issue.

Thanks,

Tony
 
C-65? MoGas? Just do it!

I don't think our J-3 saw Avgas in the ten years we owned it - probably would have died of fright at all that octane! The manual from Piper (such as it was) stated something like "use gasoline of at least 75 Octane", or some such. We we perfectly comfortable with what we got at the local Texaco, and saw no need to bother the FAA asking for an STC for an engine/fuel combination for which they would have no answer... ;)

I miss that Cub....

Paul
 
Does anyone see any problem with running mogas in a lycoming with a 9:1 compression ratio? I'm speaking specifically of the H2AD model. It has one of the highest compressions of all the 320's.
 
IMHO 9:1 compression is too high for mogas in our large bore engines. One problem is that these engines are so noisy that you can't detect pre-ignition 'till it's too late. You would stand a good chance of burning a hole in the pistons.
Mel...DAR
 
Wouldn't it be perfectly safe to use Mogas in an auto engine?

There shouldn't be a problem there should there?

John
 
I'm beginning to believe that engine compression is somewhat irrevelant. I could be way off here...but I certainly don't want to find out the hard way. I was just wondering if someone out there had practical experience with the H2AD and lower octane fuels.
 
In auto engines the ignition timing is controlled by the computer. A Lycomning does not. If the auto engine installation includes the CPU, then mogas should be fine for that configuration.
Mel...DAR
 
I can't wait till they get rid of that nasty stuff.

I just cleaned and gapped my plugs last Saturday for the 2nd time this year. I don't think I'd miss digging chunks of lead out of my plugs one bit. Does anybody else remember the bad old days before no-lead when cars needed a tuneup every year and rarely made it to 100K? That's the time-warp aviation has been stuck in since WWII.

Practically everything flying with pistons can run on 93 octane. If 100LL was outlawed, we'd get a new avgas that was more stable version of no-lead mogas. It wouldn't be so susceptibile to vapor lock and it wouldn't gum up your carb like mogas does if you don't use it fast enough.

The only good thing about 100LL is that it's a pretty pretty blue color and it smells nice. I can't wait till it's gone.
 
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