JHW
En-Route
Run a tank of 100LL to protect the valves from what? Protect them from staying too clean?
More questions re: autogas
- Thread starter JOhnH
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timwinters
Ejection Handle Pulled
Nate, it's my understanding the ethanol is NOT added at the refinery. It's added at the terminal at the end of the pipeline because ethanol will separate from the gas going down the pipeline.
So, if you have a terminal nearby, and they'll sell you gas, then you should be good.
Around here we have one airport selling MoGas and two nearby towns on lakes with non-ethanol premium.
So, if you have a terminal nearby, and they'll sell you gas, then you should be good.
Around here we have one airport selling MoGas and two nearby towns on lakes with non-ethanol premium.
Looks like the closest places are in Tool and Greenville to the east and Gainesville to the north...not very handy if you live in the bowels of DFW.
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Dr. O
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Ethanol is added to the gas at the terminal as the tanker is loaded.
We buy ethanol free mogas at the local terminal. They like it to be at least 200 gallons because they have to have a man come out and hook up a manual hose to pump it in a small tank.
JOhnH, there is no such thing as a "small' intake leak. Even an invisible crack in the intake will cause trouble. My Apache - new cylinders installed - right engine ran good, idled like crap.
Long story short: There was a crack in the intake pipe that was not visible when it was on the engine and was hidden under the hose clamp for the EGT probe. It was about 0.25" long and was only detectable to the finger when delicately rubbed across. Given it had a hose clamp band over it the amount of air that would pass was miniscule - and was enough to upset the mixture at idle.
I found it after the mechanic had snatched himself bald. Pulled the tube, a quick braze job, and we were good to go.
In your case:
1. Have they tried blowing propane or starting fluid around the intake while it is idling? (WD40 works also - and it smells good)
A rise in RPM indicates an intake leak.
2. Is the throttle shaft (butterfly) sloppy?
If so, you need the bushing kit installed. Even small things like this can cause mixture imbalance. (besides air being sucked around the shaft, the butterfly is cocked in the throat.)
(Is it the correct dash number of carb? I had that on one engine and it caused no end of misery until found)
3. Is there an exhaust leak on that cylinder? (Might seem silly, but I have seen it cause trouble)
When landing if you have any "popping" when you quickly close the throttle coming over the numbers you have an exhaust leak.
4. Could be a bad cylinder barrel - excessive choke. I have seen that before.
5. Could be a top ring that did not seat, allowing blow by. (it will still be 79/80 on compressed air)
6. Could be an intake leak on the exhaust seat. Have to lap the valve to prove it. (yes, the valve will eventually burn up - no, it will not always show on the differential air tester)
7. Could be a bent or twisted connecting rod.
Might be in the end, after you have ruled out everything else, you will have to temporarily put a different cylinder on that hole to prove that it is the cylinder causing the problem, or not.
We buy ethanol free mogas at the local terminal. They like it to be at least 200 gallons because they have to have a man come out and hook up a manual hose to pump it in a small tank.
JOhnH, there is no such thing as a "small' intake leak. Even an invisible crack in the intake will cause trouble. My Apache - new cylinders installed - right engine ran good, idled like crap.
Long story short: There was a crack in the intake pipe that was not visible when it was on the engine and was hidden under the hose clamp for the EGT probe. It was about 0.25" long and was only detectable to the finger when delicately rubbed across. Given it had a hose clamp band over it the amount of air that would pass was miniscule - and was enough to upset the mixture at idle.
I found it after the mechanic had snatched himself bald. Pulled the tube, a quick braze job, and we were good to go.
In your case:
1. Have they tried blowing propane or starting fluid around the intake while it is idling? (WD40 works also - and it smells good)
A rise in RPM indicates an intake leak.
2. Is the throttle shaft (butterfly) sloppy?
If so, you need the bushing kit installed. Even small things like this can cause mixture imbalance. (besides air being sucked around the shaft, the butterfly is cocked in the throat.)
(Is it the correct dash number of carb? I had that on one engine and it caused no end of misery until found)
3. Is there an exhaust leak on that cylinder? (Might seem silly, but I have seen it cause trouble)
When landing if you have any "popping" when you quickly close the throttle coming over the numbers you have an exhaust leak.
4. Could be a bad cylinder barrel - excessive choke. I have seen that before.
5. Could be a top ring that did not seat, allowing blow by. (it will still be 79/80 on compressed air)
6. Could be an intake leak on the exhaust seat. Have to lap the valve to prove it. (yes, the valve will eventually burn up - no, it will not always show on the differential air tester)
7. Could be a bent or twisted connecting rod.
Might be in the end, after you have ruled out everything else, you will have to temporarily put a different cylinder on that hole to prove that it is the cylinder causing the problem, or not.
timwinters
Ejection Handle Pulled
I guess that's one way to keep EGT's cool...mount the probes on the intake side. :wink2:
Capt. Geoffrey Thorpe
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True.
Well, that depends.
They may only have blendstock which requires the addition of ethanol to get up to the target octane rating.
http://www.eia.gov/dnav/pet/tbldefs/pet_move_wkly_tbldef2.asp
Tony_Scarpelli
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I was thinking the ethanol lowers octane.
Anyway, I googled a map of mogas and it looks like there is no shortage of mogas in texas although Dallas is in a restriction zone.
http://pure-gas.org/extensions/map.html
Anyway, I googled a map of mogas and it looks like there is no shortage of mogas in texas although Dallas is in a restriction zone.
http://pure-gas.org/extensions/map.html
timwinters
Ejection Handle Pulled
True. They've been pumping "sub-grade" gas to our terminal for about 2 years now. But, if you buy premium at the terminal then you're still getting at least 89 octane (91 after adding ethanol) and that works fine for my O470.
There used to be a lot more non-ethanol premium available around here before they started sending "sub-grade" gas up the pipeline.
Used to be the gas was 87 octane coming out of the pipe at the terminal before they added ethanol. Now it's "sub-grade" (85 octane) and the 10% ethanol bumps it two points back to 87.
Mo law requires 10% in both regular and mid-grade but not premium. Before the switch to sub-grade gas, most stations here simply shut off their blender pumps and you got 89 octane regardless of if you pumped regular or mid-grade. You paid more for the mid-grade but got the same gas.
But, now that they're pumping sub-grade down the pipeline, the blender pumps must be turned back on for the mid-grade to be 89 and they can no longer sell non-ethanol premium because, if they did, then the mid-grade would only be 5% when the law requires 10%.
So, now, if a station in Missouri wants to sell non-ethanol premium, they must have three tanks and buy pre-blended mid-grade. Or not have mid-grade.
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If you're talking about Ethanol by "E" above, the above is patently untrue. Ethanol is NOT added at the pump. It's added at the terminal. It's not the case that a terminal even has blending stock that can be sold without the ethanol added. Finding a wholesaler that's willing to sell you is unlikely no matter what his stocks are and frankly it is illegal for him to fill a 55 gallon drum and for you to transport it like that.
It's true that ethanol is bad for boats, but you're mistaken if you believe that all gas sold at Marenas [SIC] is ethanol free. The marinas are having a difficult time obtaining ethanol-free gas as anybody else.
timwinters
Ejection Handle Pulled
This is quite variable from region to region. It's EASY to find ethanol-free gas in some areas...hard in others. It's a topic on which blanket statements don't work well.
Tony_Scarpelli
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When I decided to use mogas I called a few stations to locate it and then I met VP of Phillips Costal Marts and he said they never use E because they produce gasoline 100 miles away in Bartlesville and it is cheeper than buying E and adding it. So I bought all my gas from Costal Marts from that point on. I bought 2 5 gallon non vapor jugs from walmart and took 10 gallons out each visit to the airport. This worked pretty well since each flight was about 1 hr or less burning 7 gallons. Soon I had extra gas which I left the full jugs at the hangar. Kept the plane filled and took the empty cans with me.
When I wasn't able to fly the Cherokee as often as I liked, mostly because I was flying my new to me Comanche instead, I allowed my brother and a few friends to fly the Cherokee and pay the bills on it as I wasn't ready to sell it yet.
One of my non equity partners was friends with a fuel jobber. He didn't like buying from Coastal marts and we got a 55 gallon barrel from craigslist, cleaned it out to our satisfaction and then the jobber buddy filled it for us. We then pumped the mogas into 5 gallon jugs and brought 1 or 2 or 4 cans out to the hangar each visit.
It was easy as pie.
I do not see why people make this difficult.
When I wasn't able to fly the Cherokee as often as I liked, mostly because I was flying my new to me Comanche instead, I allowed my brother and a few friends to fly the Cherokee and pay the bills on it as I wasn't ready to sell it yet.
One of my non equity partners was friends with a fuel jobber. He didn't like buying from Coastal marts and we got a 55 gallon barrel from craigslist, cleaned it out to our satisfaction and then the jobber buddy filled it for us. We then pumped the mogas into 5 gallon jugs and brought 1 or 2 or 4 cans out to the hangar each visit.
It was easy as pie.
I do not see why people make this difficult.
wabower
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As you readily admit, your quest for the cheapest answer to any aviation question has reached near-religious proportions. Some people elect to attend a convenient church that's closer to home rather than drive all over town trying to find one that doesn't pass the plate.
Tony_Scarpelli
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Thus my preface there are pilots who do and pilots who won't use mogas.
Simple as that.
But then there are some, they ***** because they cannot do it easily, its too hard, its out of the way, its......
docmirror
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Tony_Scarpelli
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Show me an airport, area that truly does not have mogas available and I will show you a business opportunity.
https://www.google.com/search?q=sel...28%2Fcoastal-bend-airports%2F76252%2F;607;436
docmirror
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Cowboy - yeehah!
What a wonderful use of the hyperbole.
Many GA owners go to serious lengths to exercise their privileges. I also don't see the big deal in transferring gas if one has a truck. Being that we're in TX, we were all given a Ford/Dodge truck when we put down roots in the state of course.
I've hauled and poured hundreds of gallons at the airport over the years. There is a point when it no longer makes sense, and I'm near that point now cause I also have to travel a bit to find non-Eth gas. I do make some travel diversions for mogas though. I find it runs cleaner and cooler than 100LL in my old wagon.
JOhnH
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Yeah, people like me that are trying to run down a high CHT problem and ask if Mogas would cause the CHT to be as high as 100LL. One person says Mogas makes his engine run HOTTER. Then all the experts chime in calling each other idiots because they don't know how octane is calculated, or whether ethanol is added at the refinery or at the terminal or at the pump or whether it is sold at marenas? or not?
Remember that my original post was a question about whether or not there was a chance mogas would run cooler and the only person that addresses it says no, just the opposite. So I say I won't use it, then some loudmouth tries to degrade me as foolish and lazy because I don't have the time or inclination to bootleg my own gas and break the law and my lease by having portable gas containers in my hangar and you say that bitching. All because you are the cheap one that can't afford to(or won't) buy legal gas and think you are a better person for it.
Jeez.
denverpilot
Tied Down
Makes sense. Our terminals are at or near the refinery here. One refinery, no significant population density away from Denver. Probably terminals in Grand Junction from Utah refineries and a terminal in Colorado Springs fed from who knows where. Haven't looked at a pipeline/terminal map in 20 years, but not much has changed.
They are running a new natural gas pipeline through my county on the county road out front of the house along an existing natural has right of way. Really cool to see miles and miles of pipe laid out on top of the ground, as they're starting to bury it. Looks like at least a 12" inner diameter pipe, if not bigger.
The corner of Singing Hills and County Road 29 has become a twenty or thirty car/truck temporary parking lot for all the workers. They've got about ten miles of pipe laid out above ground. Will be interesting to see how fast it goes in the ground.
docmirror
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Cowboy - yeehah!
Um, the post above this contained my experience that mogas ran cooler. Bonanza, with E-225(O-470, lo comp) engine. In many ways similar to the old O-300 Conti in early 172s, but I don't know what your plane has.
Also, Charlie M has opined and I trust him that you can't run mogas with your STC anyway.
JHW
En-Route
denverpilot
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Skylane81E
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And pilots who can't...
denverpilot
Tied Down
Maybe we should write a letter to the Chief Counsel and ask something about MoGas so we can get it banned by fiat.
JOhnH
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And there are also probably pilots that grow their own wheat to make their bread and sew their own clothes too. I guess we should all be like them
Anyway, I just found a place about 12 miles from me that sells 93 octane non-ethanol gas for $4.93/gal. 100ll cost me $4.99 at my home drome.
I must be an idiot for not trying to Save that 6 cents/gallon. That would be almost A DOLLAR A WEEK!
Skylane81E
Final Approach
I could save $1.00-$1.50/gal burning auto gas
IF
1) I drive about an hour each way or fly a 120nm round trip
And
2) I sold my plane and bought a diffent one
That's as near to can't as makes no difference.
JOhnH
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Ok, I feel bad about taking a mildly irritating comment, that could actually have been meant to be funny, and turning it into a big feud. I apologize.
But in my defense, I was trying to track down a problem I have been having for years. I have spent thousands and thousands trying to find why I have CHTs in the 400s. I wasn't trying to debate the merits of mogas over 100ll. But after almost 4 years and one blown engine (at 1,000 feet it had a catastrophic failure on the engine that had consistently run the hottest) I was getting desperate. I have had multiple A&Ps and IAs look at it and scratch their head. One of them relocated the oil cooler (after conferring with Cessna) but that didn't help. I have had all the seals replace and double checked several times. I had the mags rebuilt (they needed it anyway). I had the EDM 700 checked and calibrated and had the probes moved. I even bought all new probes.
So I asked whether mogas might help. I didn't meant to stir up a hornets nest but until I get this problem fixed, I am not making other random changes.
Again Tony, I apologize for flying off the handle.
JHW
En-Route
It's not a money issue for us. I'd pay more for some unleaded fuel that I could put in my plane.
Skylane81E
Final Approach
Nice!
You may be looking at a case where the cooling provided for 160hp isn't enough for the bigger engine, but I would have that carb checked out, if it is running too lean...
JOhnH
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Funny you should mention that,
But after Brian, in another thread mentioned that he had the wrong carb,
and after Charlie (of Zephyr engines) specifically mentioned that I might have a 10-3878 carburetor, which would be too lean, I did further research and found that Pen Yan specifies the upgrade for my plane to be an O360-A4M. I have an O360 A4A with a 10-3878 carb, as Charlie Guessed. Further research showed the A4M should have a 10-5193.
So I called Pen Yan (The holder of the STC) and talked to Jeff. His first question was "what carb do you have?". I told him I have a 10-3878 and he said that is the wrong one. That is for a Piper installation. My Cessna should have an A4M with a 10-5193 carb.
I will see what happens when I have that change made. Personally, I dont' care what it costs but I am rather ticked that none of my mechanics could figure it out but POA could. (I hope).
SoloEqs
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You may blend gas for a living, but if you do some research into aviation history, you will find that when 80 / 87 was developed (back in the early 1930s), it was intended as a replacement for the "Ethyl" midgrade autogas of the time, which was rated 80 MON / 87 RON, and which was the fuel for which most aircraft engines were designed -- including such powerhouses as the Napier Lion and the Liberty Engine -- simply because most aircraft fueling was done with a long gas hose from gas stations next to airfields.
in the early 1930s, Shell hired Jimmy Doolittle to fly all over North America to convince pilots to use their new "Aviation Gasoline," which cost 18 cents per gallon (compared to 13 cents for Shell's autogas) and was formulated to a more stringent standard. Planes with mixture controlled carbs were able to lean more accurately with "Avgas" than they could with "straight" gasoline, as engines ran more smoothly at altitude. It was this development that led to separate paths for aviation fuels and other types of gasoline, but during WWII, the Army and Navy were often forced to run autogas in higher-compression engines, and as late as the Korean War, the US Army was using standard mogas for their planes and reserving Avgas (115 / 135) for helicopters, simply due to logistics questions.
BTW, it was this problem which led the DOD to develop "Multifuel" engines for their trucks, and eventually go to JP-8 for pretty much every liquid fueled engine in the military.
Todd Petersen, who I think we can all consider to be pretty much the top expert on using autogas in aircraft engines, told me that valve recession was a problem with unleaded fuel, and the solutions were either hardened parts or to "run an occasional tank of 100LL perhaps every 50-75 hours and unleaded auto fuel the rest of the time."
NineThreeKilo
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15.5 gal stainless beer kegs make GREAT fuel transports BTW.
SoloEqs
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Lessee, that 60-mile round trip would cost me 4 gallons with my Diesel Suburban, so the cost for the run is about $16. If the price difference is $1 per gallon, that means that I'd save $5 if I only bought enough to fill 4 Jerry cans.
However, since avgas here is currently TWO dollars per gallon more than autogas, and I will buy 80 - 100 gallons at a time, savings will be about $200 per load, which will pay for the trailer, tank, pump, battery, hose and nozzle on the second trip to the POL jobber (10 miles each way). After that, I'll be knocking nearly $10 per hour off of the cost of flying.
That's worth it to me.
SoloEqs
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YMMV. Around here, 87 octane no-booze autogas is $3.84/gal, and 100LL is 5.87/gal.
docmirror
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Back when I researched it, the delta was $1.16 between the local FBO and the local non-Eth mogas. Also worked out to about $10/hour. I figured I could be lucky if I could run 60% mogas without too much trouble. Over the life of the engine at 1600 hours, I would save about $9600. That was worth it to me, YMMV.
Frank
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Are any of you worried about the plight of the FBOs who will have to find a way to make up the lost fuel revenue or go out of business? If they charge you more for other stuff, what good did it do? If the airport closes, then you really screwed yourself.
wabower
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A local FBO mgr at KADS (big city reliever) told me that his 100LL sales drop precipitously when price exceeds $5/gal. I think the most I've paid in the N Texas area has been $4.87, price usually hovers around $4.50. Only the smallest of the small-town FBOs try to make a living on avgas. All others depend on kerosene to feed the bulldog.
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Greg Bockelman
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Do you really think that is going to be an issue? I bet most people will not bother to haul gas because it IS a bit of a hassle.
JHW
En-Route
no I found it in a duplex left behind by the former tenants in the late 1980's. 50 gal really isn't enough to fuel a plane but its fine for a weekend of waterskiing.Hey Jeff. Did you buy that tank from me? It looks just like the setup I sold when we moved back to KC from Dubuque.
Geico266
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I've pumped over 10,000 gallons of unleaded fuel through this baby.
I've saved over $12,000 burning mogas.