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IO-320 and Mogas

PH-SCP

Well Known Member
Hello guys,

I have the opportunity to buy a low time Lycoming IO-320-B1A engine for my RV-9. However, based in Europe I do not want to run my airplane on AvGas, it's just getting too expensive.

I am looking for advise whether or not it is possible to feed an IO-320-B1A engine with MoGas which in our part of the world has an octane number of 98 and is still available without ethanol/methanol from certain providers such as Esso.

Your 2 cents are most welcome :)
 
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Running an IO-320-B1A on mogas should not be a problem!
Just remember that that engine has a "type II" dynafocal mount. So make sure you get the correct mount from Vans.
 
No mogas implications for use w/ fuel injection? No increased liklihood of vapor lock compared to carbs?
 
Have a look here.

There might be a very good reason why not to.

http://www.autofuelstc.com/autofuelstc/pa/Start_Here.html

I am hoping to have a good long chat with George Brayly in the next week about this very topic. If I have any gems I will try to report back.

Out of interest, he was in Europe this last week and i am not sure that it was holidays. G100UL could be the answer in Europe some day.
 
Have a look here.

There might be a very good reason why not to.

http://www.autofuelstc.com/autofuelstc/pa/Start_Here.html

I am hoping to have a good long chat with George Brayly in the next week about this very topic. If I have any gems I will try to report back.

Out of interest, he was in Europe this last week and i am not sure that it was holidays. G100UL could be the answer in Europe some day.

I don't see any injected engine in the list of mogas-approved engines, keeping in mind that the list is for certified aircraft. However, I guess there is a good reason for that and I bet it could apply to experimentals too, unless Petersen never bothered to look at IO-320's....
 
I think it will be all about vapor locking in the fuel delivery system. Carby engines do not have the same exposure.

Otherwise there is not much difference.
 
O 320D2J

Mine runs fine on 92 or 93 Octane no ethanol . Usually keep 100LL on one side and Mogas with No ethanol on the other side. usually switch to the 100LL for take off and on return to the pattern. That should purge any Mogas out of the carb and system while sitting in the hanger.
 
So .... during Thanksgiving we'll be at Lake Tahoe at our timeshare. Just up the street they sell alcohol free gas.... we're going to bring back as much as we can safely carry and do some testing.. we'll let you know what we find....
 
So .... during Thanksgiving we'll be at Lake Tahoe at our timeshare. Just up the street they sell alcohol free gas.... we're going to bring back as much as we can safely carry and do some testing.. we'll let you know what we find....

Is your plane IO-320 powered ??
 
Simon...

I think you are missing the point a little ;)

The "engine", be it (I)O-320/260, will run quite happily on Mogas, provided said Mogas gets to the engine, and round the pipework, in liquid form. And some engine manufacturers are quite happy to say as much, others dragging their heels a bit ;)

The problem is the airframe / cowling / fuel delivery installation. And RVs can suffer more by being tightly cowled.

Our RV-8, not helped by a black topped cowling, suffers from fuel vapourisation on the ground, on hot days / hot engine with Avgas. There are ways we could "mitigate" this (mech fuel pump cooling, fuel return lines, run booster pump).

The people to ask will be those regulating your aircraft when it will be flying. They will say whether they will allow it or not. Provided they allow it, or you decide to use it anyway (;)), I am sure you'll be OK, subject to some precautions as above.

The UK is one of the stricter places, and following the Safety Sense Leaflet and CAP 747, there are type / engine combinations, including O-320 [not sure about IO?] approved.

I do not see RVs getting added to that list, since the fuel system is too variable between builders to get an "approval".

Andy & Ellie Hill
RV-8 G-HILZ
RV8tors
 
This is always a "hot" subject and one that can raise the blood pressure.

One of the posters refers to fuel injected motors. Only the Conti IO 470 passed the tests. The Bendix injection did'nt. I don't want to put you off Simon. I know of many lads that fly their non type certified aircraft (RVs) on Mogas with no issues whatsoever. Here in South Africa we too are lucky enough not to have Ethanol in our fuels (yet). By law - the fuel companies are allowed to blend up to 2% but thankfully don't.

A useful thread can be found here (The first few posts won't interest you too much):

http://www.avcom.co.za/phpBB3/viewtopic.php?f=1&t=78297

Vapour Lock is usually an airframe issue - hence two STCs are sold by either EAA or Petersens - one for engine and the other for the airframe.
 
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We have mogas with E10, and have noticed only improvement in plug life, both fuel and oil reduction, on two airplanes, with certified and experimental engine, 1200 cumulatively. No vapor lock nor even an indication of it.
 
Hello guys,

I have the opportunity to buy a low time Lycoming IO-320-B1A engine for my RV-9. However, based in Europe I do not want to run my airplane on AvGas, it's just getting too expensive.

I am looking for advise whether or not it is possible to feed an IO-320-B1A engine with MoGas which in our part of the world has an octane number of 98 and is still available without ethanol/methanol from certain providers such as Esso.

Your 2 cents are most welcome :)

Hi,

Sorry for reopening this old post, but I am in the same situation as you were two years ago. I am living in Belgium, planning to put a IO-320-B1A in an RV9. I want to know what you finally did related to this subject. All information is welcome. Thank you!
 
A lot depends on your local regulations. Look at the latest SI1070 from Lycoming and see what types are approved for Mogas.

Apart from the vapour lock issues, you also have to worry about ethanol. I'm not sure how many places in Europe (if any) you can still get Mogas without ethanol.

There's also UL91 and 91/96UL available at various places in Europe which may be a little cheaper.
 
Cool the Fuel...

Hello guys,

I have the opportunity to buy a low time Lycoming IO-320-B1A engine for my RV-9. However, based in Europe I do not want to run my airplane on AvGas, it's just getting too expensive.

I am looking for advise whether or not it is possible to feed an IO-320-B1A engine with MoGas which in our part of the world has an octane number of 98 and is still available without ethanol/methanol from certain providers such as Esso.

Your 2 cents are most welcome :)

Simon,
I grew up working alongside my IA Dad who used 100% MoGas in our family's 57' Cessna 182 for over 30 years. Never had a problem, ever.
I operated my Harmon Rocket with an IO-540 C4B5 and electronic ignition/Bendix F.I. for 5 years/700 hours primarily on 91 octane non ethanol MoGas readily available here in FL.
Here is some data and techniques/lessons learned.

My Dos Centavos...

1. I always mix Marvel Mystery Oil into the MoGas per recommendations on the container. It provides upper cylinder lubrication.
2. I never stored MoGas for later use, always recent purchases. It breaks down over time.
3. Boost Pump on below 1000' AGL period. This includes ground operations, taxi, etc. The cold fuel circulation is key to avoiding Vapor Lock.

4. Hot starts: Boost Pump on 10 seconds prior to engaging starter. Once prop is spinning and the Electronic ignition fires, full rich. As I said above, leave BP on throughout ground ops.

5. Longer run up in summertime. It's always summer here in FL so I would perform a standard run up then a 30 second run at 1500 RPM to insure cold fuel had reached the engine.

Conclusion: MoGas can not only be safely employed in airplanes, I believe it will be the only fuel available in 10 years.

V/R
Smokey

FAA MoGas Certified engine approval list: http://www.autofuelstc.com/approved_engines_airfames.phtml

Great article on MoGas use:http://generalaviationnews.com/2011/03/16/10-mogas-myths/


PS:Van actually included drawings in my original RV4 plans from 1989 showing a fuel routing system for MoGas use to avoid vapor lock!

PSS:Two current fuel injection systems manufacturers willingly approve MoGas in their systems, Airflow Performance and Silverhawk(Bendix clone). The FAA STC approval list of certified engines approved to use MoGas doesn't include any "IO" engines, mainly because Bendix wouldn't approve their injections systems for MoGas. The real truth is nobody tested an IO to get enough data for the STC...
 
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IO-540 Mogas with ethanol

Simmon,

With very little modification to the fuel delivery system you can easily operate on mogas with or without ethanol.
Fuel injection is your friend when it comes to mogas because of higher fuel pressure and if you use the Airflow performance fuel injection you will have an injection system actually approved by the the manufacturer for use with almost any kind of fuel.
What will and will not be approved in Belgium I cannot tell you but mogas E10 has worked for me now going 200 plus hours over a 2 year period.
I have tested extensively especially on hot days to be sure no vapor lock issues lurk in my system.
I cannot report a single occurrence of anything but smooth engine operation in any condition but especially in temperatures over 100F. I can't think of any other tests I could perform to proof the system is vapor lock proof with mogas/ethanol.
 
Mogas in IO-320

A client tried to run non ethanol mogas in an IO- 320 in a 7KCAB Citabria. It ran fine in winter. As soon as wx began to warm up (above 80F) It got vapor lock. Boost pump did not help. Peterson Aviation advised there was no STC on the IO-320 Bendix fuel injection system due to vapor lock issues. This particular plane had been carbureted when the STC was issued and was changed back to the Bendix system. The owner thought the STC was still applicable. I suggest you contact Peterson for advice.
 
A lot of certified engines had type certificates for mogas with compression ratios of 8:1 or less.

2 things to remember when setting up for lower octane gas:
Detonation and Vapor lock.

Compression ratio generally speaking has the greatest effect on detonation when using low octane gas as well as efficient cooling etc.

Vapor lock happens in a poorly designed fuel system where boiling of fuel is allowed to occur.

IMG_2462.JPG


IMG_0458.JPG
 
Approved

Lycoming approves the IO-320-B1A for operation on 93 octane (R+M/2) Premium unleaded. See Lycoming service instruction 1070S for details.
 
Great info on the Lycoming bulletin. Thanks for that information. I'm thinking of building an RV-9a with an IO-320.
 
Simmon,

With very little modification to the fuel delivery system you can easily operate on mogas with or without ethanol.
Fuel injection is your friend when it comes to mogas because of higher fuel pressure and if you use the Airflow performance fuel injection you will have an injection system actually approved by the the manufacturer for use with almost any kind of fuel.
What will and will not be approved in Belgium I cannot tell you but mogas E10 has worked for me now going 200 plus hours over a 2 year period.
I have tested extensively especially on hot days to be sure no vapor lock issues lurk in my system.
I cannot report a single occurrence of anything but smooth engine operation in any condition but especially in temperatures over 100F. I can't think of any other tests I could perform to proof the system is vapor lock proof with mogas/ethanol.

The problem with ethanol is not Vapor lock.
This is an old article in a newspaper but well worth the read on why we shouldn’t use gas containing Ethanol in our aircraft.

https://www.theglobeandmail.com/glo...lem-with-ethanol-in-gasoline/article29103634/

Cheers
 
Mogas vs vapor pressure

Enclosed is a diagram for vapor pressure in Mogas.
It is interesting to note that adding more Ethanol than 2% will mot increase
vapor pressure. Fuel standard for AVGAS allows up to 1% alcohol.
 

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Enclosed is a diagram for vapor pressure in Mogas.
It is interesting to note that adding more Ethanol than 2% will mot increase
vapor pressure. Fuel standard for AVGAS allows up to 1% alcohol.

It should be noted that is not total vapor pressure - that shows vapor pressure INCREASE with ethanol addition.
 
Kyle at AFP instructed me. I learned that if I understand what factors make Mogas pass or fail, then I will understand that the airframe that used it for 20 years with great results really gives us little information for your installation

Its airframe dependent if your io-320 installation will be satisfactory. Your objective is to keep the fuel cool.

If the fuel gets hot, it hurts your chances of passing. So keep the mass of the fuel delivery on the cool side of the firewall like your gascolator. Keep your fuel lines short on the hot side of the firewall and away from the exhaust. A cooling shroud around the fuel pump will help.
 
Kyle at AFP instructed me. I learned that if I understand what factors make Mogas pass or fail, then I will understand that the airframe that used it for 20 years with great results really gives us little information for your installation

Its airframe dependent if your io-320 installation will be satisfactory. Your objective is to keep the fuel FROM BOILING.

If the fuel gets hot, it hurts your chances of passing. So keep the mass of the fuel delivery on the cool side of the firewall like your gascolator. Keep your fuel lines short on the hot side of the firewall and away from the exhaust. A cooling shroud around the fuel pump will help.

Slight correction to your post... hot fuel does not matter as long as it's in liquid form. Higher system pressures can keep it in liquid form at elevated temperatures. First and foremost, as you noted, do everything you can to keep it cool.
 
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