MoGas?

[rdv]

Any opinions on MoGas is a IO-360 A1A? Maybe blending with AvGas? Perhaps premium car gasoline?

[carusoam]

While you are thinking about the engine and it's octane rating and whether or not lead is needed...

Other things for your consideration...

The tank sealant, and all of the seals and floats from the tank, through the pumps then into the fuel injection or carburetor systems.

Then think at what altitude you fly at.  Avgas does not evaporate with the same pressure that moGas does.

Overall, You will want your new gas to not dissolve away your sealant or swell your seals, and at the same time you don't want it to vaporize in the fuel system before it's supposed to.  And of course, you don't want it to detonate and damage your pistons.

Mogas in NJ this week $2.60  Avgas $4.00.  There is definitely some room for invention.

Any fuel engineers on the board?  I know there are couple of us in the fuel and oil industry.....

Check out what the good people at GAMI are working on for 100LL fuel replacement and electronics that work with MoGAs  http://www.gami.com/prism/prism.php.

Best regards,

-a-

[DaV8or]

My understanding is that many of the planes that don't have Mogas STCs are more due to the airframe than it is the engine. I believe NA Mooneys fall in this catagory.

[Kwixdraw]

The vapor pressure issue is related to iceing and that alone would rule it out for me. Also you will have difficulty finding mogas that is unaduterated with ethanol or MTBE depending on location and time of year. Then again you have the 91 octane west coast vs. the 93 octane east coast. Too many variables for me.

[scottfromiowa]

Or the current apparent push for 94 No Lead...100 Low Lead...without the lead.  The concern, as I have read, is the big higher compression engines/big engines would have issues.  I would definitely like to know how the I0-360 runs on 94 No Lead.  Wouldn't the price come down based on the elimination of this expensive additive?  Win for the environment and majority of general aviation that does NOT require the lead, but pays the premium out of necessity.

[KSMooniac]

It is my understanding that the O-360 180 hp engines would run fine on 94UL, but hte 200 hp IO-360s will not.

We really need to rally together to end up with a 100UL spec replacement fuel, otherwise we'll all be S.O.L.  The planes that *need* 100 octane are the "working" planes that buy the bulk of the fuel today, and if they cannot fly, then there will not be enough volume to support the infrastructure to manufacture and deliver any airplane fuel.  Thus, if 94UL is all we get, only the lower-performance planes could use it, and they won't be able to buy enough of it to make it a go for the refineries and FBOs.

[OR75]

2016 seems to be the EPA deadline.

Looks like C engine maker is pushing for 94UL and Diesel while engine maker L wants  a "no lead" 100.

unless  a no lead 100 is found, we could endup with a derated engine (<200hp), or a derated IO-390 or a new engine

a critical issue for Mooney owners (and others) IMHO.  Not as critical for others where Mogas STC are very common.

 

  

[N201MKTurbo]

First off, the IO-360 has one of the highest HP/cu in ratings out there. It is a high strung engine.

 

I don’t see what the big deal is with de-rating the engine. It would require a slightly longer takeoff roll at low altitude airports. At cruse we typically set our engines at 75% power (150 HP) we use these power settings for engine structural and thermal considerations. If the max power of the engine is reduced there is no reason that we couldn’t still cruse at 150 HP.

 

If the engines are de-rated by imposing a limit on manifold pressure, the low elevation takeoff will be the only thing affected. If the engines are de-rated with a timing change then the service ceiling will also be reduced.

[eaglebkh]

Quote: N201MKTurbo

I don’t see what the big deal is with de-rating the engine.

[N6843N]

In the 90's I had a very good friend with an early "C" that was, shall we say "thrifty". He kept his left tank filled with unleaded auto gas and the right one was 100LL. He always took off and landed with the right tank and any cruise above 75% power was also done on the right tank. I flew with him several hundred hours under those conditions and I can say he never had a problem. I only posted this so folks will know it can work in a Mooney airframe. I only run 100LL in my plane because I worry about the effect autogas would have on tank sealant.

[Kwixdraw]

Yeah and then after they saddle you with UL fuel and engines start having inflight problems with valves and pistons you will hear them cry, "Those little planes are just not safe...ban them."  We better get off our duffs and find something that really works for all of us.

[DaV8or]

I don't see how there would be any difference between the O-360 and the IO-360. The compression ratios are the same IIRC. The difference is the injectors provide a more effiecient fuel delivery and therefor more HP on the same fuel burn. High octane rating is needed to retard detonation and detonation is purely a function of compression of the fuel/air mixture. Engines with a compression ratio above 9:1 and forced induction are the ones that really need high octane fuels. So our brothers here with turbos are the ones that should really be worried. If the turbo is nomalized to sea level and there is no boosting above normal barometric pressure on take off or low level flight, then they could be OK.

I had read before that most airframes that don't have STCs for Mogas is because of the fuel delivery systems than it is the engines. I believe our Mooneys fall in this catagory. The problem is Mogas has additives like ethanol and MTBEs that are not compatible with our boost pumps, fuel pumps, fuel lines tank sealant, etc. That's not to say that it couldn't be, it's just that nobody has wanted to spend the money and time getting an STC for what would be a very expensive conversion. I believe that the aviation 94UL will work fine in O-360s and IO-360s. Turbos I'm not so sure.

BTW, what ever happened to the aviation ethanol fuel they were working on? It sounded very promising. They were saying last year at Air Venture that it could be made cheaper than 100LL, burn cleaner, take care of detonation problems better than Avgas and best of all, give OPEC the finger! Maybe they will give us an update this year.

[KSMooniac]

Again, O-360s are not the same as IO-360s.  The compression ratio is higher on the IO-360, and mogas or 94UL is not suitable without a knock-sensing electronic ignition to be able to tolerate the reduced detonation margins safely.

 

[OR75]

8.5:1 for 180hp and 8.7:1 for 200hp  (naturally aspirated)

 

 http://www.lycoming.com/engines/series/pdfs/360ci%20Engine%20Insert.pdf

 

 

[carusoam]

From our friends at GAMI who are working on a new fuel.....

Anthony,

 We have an unleaded 100 motor octane fuel. G100UL.

 We are actively waging certification with the FAA right now. 

 Thanks,

John-Paul

 

 

John-Paul Townsend - Sales/Support Manager

General Aviation Modifications, Inc.

john-paul@gami.com

toll-free: 888-359-4264

ph: 580-436-4833 x1005

fx: 580-436-6622

www.gami.com

 

 

[scottfromiowa]

Can you refer me to some info to back up your statement KSMooniac?  I want to learn facts based on proven testing and they seem to be in short supply relative to IO360 and 94 no lead.

[RJBrown]

Any mention of alcohol as an airplane fuel scares me. Alcohol attacks too many existing components in our planes. To make an older Mooney "alcohol compliant" would require changes to every flexible component in the fuel system from the tank sealant to diaphragms and O rings. Pretty costly it seems to me. I understand that any mogas STC excludes the use of any fuel that contains alcohol.

At KAPA there are

Aircraft based on the field:   836 Single engine airplanes:   568 Multi engine airplanes:   135 Jet airplanes:   112 Helicopters:   21

Aircraft operations: avg 875/day * 44%  local general aviation 41%  transient general aviation 14%  air taxi 1%  military * for 12-month period ending 31 December 2008

There are 836 planes based at Centennial.

Of that total there are 112 Jets.

The avgas sales average 50,000 gallons a month.

Jet fuel sales average 800,000 gallons a month.

7 times as many aircraft using 1/16 as many gallons of fuel.

An average corner gas station sells more fuel than all the avgas at Centennial.

Avgas is a really small market. Forcing a questionable fuel for "environmental" reasons is purely for political show. There is so little lead introduced into the environment that it is silly to worry about it.

 

[carusoam]

Nice numbers Randy.  No matter what fuel we are burning it will be market driven pricing unless it is used by the masses such as diesel or MoGas.

Alcohol died down significantly with the end of the Bush administration.  Turning food into alcohol turned out to have unintended consequences.  Price of grain became highly inflated, feed for livestock went the same way, price of food increased significantly.  Percentage-wise Huge amounts of food were being used for very small amount of fuel.

Alcohol, as indicated by Randy, is very corrosive and has significantly less energy per pound.  Anything that takes away useful load is usually unpopular in aviation. 

Alcohol also has the ability to carry water with it.  If it were a drop in an entire tank, this is a good trait.  If it adsorbs as much water as it can, you would be getting a few percent watered down fuel (more pounds, less energy).

A final thought: I wouldn't mind low power fuels at altitude so much.  However, I would be very uncomfortable with low power fuels while screaming towards the end of a 2,200 ft runway. 

Best regards,

-a-

[KSMooniac]

From http://www.crcao.com/reports/recentstudies2008/UL%20AVGAS/CRC%20UL%20AVGAS%20Exec%20Summary%20FINAL%2005132008.pdf

CONCLUSIONS
 
CRC research into unleaded aviation gasoline alternatives has focused on meeting
engine octane requirements.  Research results to date reflecting the unleaded fuel
blends identified above have not identified a transparent replacement for the 100LL
AVGAS product.   Although full scale engine tests indicated some blends were capable
of providing knock free operation in the test engine, these blends represented the use of
specialty chemicals which require further evaluation with respect to environmental
impact.  Economic viability of the blends tested is not the jurisdiction of CRC and will
also need to be evaluated separately by industry.   Furthermore, blend properties were
not controlled for agreement with the ASTM D 910 specification as the primary focus
was engine octane satisfaction.
 
Although experimental blends of specialist components may achieve or exceed the
100LL specification of 99.6 MON minimum, such formulations are very different as
compared to the current ASTM D 910 product and potentially compromise other
important specifications.   Depending upon engine power output and configuration, high
performance aviation engines can require unleaded fuels in excess of 100 MON to
achieve octane satisfaction.  Leaded AVGAS 100LL or 91/98 offers greater octane
satisfaction in full size engines when compared to unleaded products of similar
laboratory MON. 
 
CRC test results are indicative of the significant challenge regarding a high octane
unleaded AVGAS formulation and further serve as a reminder that aviation fuels
represent specialized products optimized over many years to maximize performance and
flight safety.  Through the CRC, a broad range of industry expertise and facilities have
been made available to investigate this issue.   Such groups, with input from all parties,
and working in collaboration with industry offer a viable means of conducting meaningful
research.  
 
The goal remains a viable solution which assures performance and flight safety for both
the existing and future general aviation fleets.

********

In the page above the part I copied, they mention one of the test engines as the IO-540-K, which uses the same compression ratio of 8.7:1 as our IO-360-A* engines (and perhaps the exact same cylinders) to achieve 300 HP.  One can only conclude that the IO-360 is equally unsuitable for <100 octane fuel, especially without lead.

A couple years ago Lycoming announced with great fanfare they were going to approve IO- and O-360s for mogas, but then didn't follow through to my knowledge.  Like many of their public statements over the years, I think the marketing folks ran way ahead of the technical folks without looking at the real data...otherwise you can bet they would be pushing 94UL or mogas and not insisting on 100 octane like they are currently.  (http://www.generalaviationnews.com/?p=25063)

 

[scottfromiowa]

O.K., I can see why you would make the statement regarding the I0-360 engine NOT running on 94 No lead based on your statement that compressions are the same as the larger engine in the test.  I'm getting tired of:

1. Paying excessively higher fuel prices for 100Low Lead...IF I don't need it.

2. Being threatened by the government that MY FUEL is going to be pulled...over and over and over again...

3. The government, Fuel Manufacturers, Refiners, and private industry NOT coming to a concensus on a replacement for 100 Low Lead and continuing to threaten...

4. Lack of information on the IO-360 and other NON-over 200HP high performance engines testing on MoGas or other substitute that would eliminate lead.

This puppet on a string is tired of it...

[DaV8or]

Quote: RJBrown

Avgas is a really small market. Forcing a questionable fuel for "environmental" reasons is purely for political show. There is so little lead introduced into the environment that it is silly to worry about it.

[Piloto]

Logistically it makes more sense for planes to run on the most popular fuel (MOGAS). This way there is no issues about availability anywhere in the world. As an example: In Bermuda or Flores, Azores there is no AVGAS at the airport but plenty of MOGAS around. Having planes running on MOGAS would open the accesibility to these places. I have not seen any report of MOGAS affecting fuel hoses, o rings or tank sealant. In this respect MOGAS and AVGAS are pretty similar. In most A/C piston engines retarding the ignition timing would be enough to prevent detonation. The only drawback would be sligthly less power output. But that would be better than excessive fuel prices or no fuel at all.

José  

[flyguy241]

My previous aircraft was a Cherokee 140 that had an auto fuel STC.  Even with the STC you could not burn anything with ethanol.  As previous posters have pointed out, it does bad thing to seals etc.  I would use some autofuel, but never without some 100LL mixed in, especially in the summer.  When ethanol addition to autofuel became the standard, I stopped using autofuel all together.  You can find autofuel without ethanol, but you have to be carefull.  One more point, the configuration of the aircraft is a big issue with autofuel.  A high wing gravity feed fuel system has very few problems with autofuel whereas the low wing that has to pump the fuel uphill can have vapor lock issues and more so in a hot environment.  I speak from experience with vapor lock in two different Cherokees with autofuel STC's.

[KSMooniac]

Scott, for the record, I agree with your sentiments completely.

I think I recently read over on the AOPA board that the EAA/Peterson STC's for mogas covered just about every possible GA configuration that does indeed work reliably, and if they didn't get STC coverage for a particular plane then it just isn't feasible.  180 hp Mooneys of course are not covered...   The argument for mogas for us is moot these days IMO due to the damn ethanol and other crap the greenies have mandated, which doesn't meet the existing STC's I just mentioned.

I haven't read/heard anything about Swift fuel lately...I hope they're still working on the scale-up issues and can develop a solution that doesn't cost a fortune.  GAMI's fuel also seems very promising and I expect we'll learn more at OSH.  My money would be on one or both of those solutions for us...

I'll restate the most important part of this whole debate...the fuel solution *must* accomodate the high compression and/or turbo engines because the users of these engines are the ones purchasing the vast majority of 100LL today.  The fact that a Cub or old 172 can run on mogas or 94UL or whatever has no bearing on the economics of the problem.  If a business owner with a 421 or a freight dog with an Aero Commander can no longer fly their planes, there will not be any infrastructure to sell whatever avgas ends up replacing 100LL because there will not be enough volume.  That is why we need a completely transparent replacement for 100LL that will work without de-rating the existing engines.

[scottfromiowa]

I hope GAMI's mystery non-lead additive is a home run solution.  I look forward to hearing more about it.  Iowa has many idle or low producing ethanol facilities/infrastructure that could probably be vamped into switch grass production to reduce the "ramp up" volume costs.  Both seem to offer promise as an alternative FOR ALL.