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MOGAS fuel freshness test kit ?


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Water and ethanol in fuel is an easy test.

 

How can I VERIFY that the MOGAS I buy is fresh and the whole cocktail of volatiles  is present  ???

 

No assumptions are permitted. No guessing or luck is permitted for this check. 

 

Presumably, I can buy a fuel test kit to verify the volatiles are all present, short of an atomic spectrometer (which isn't hard, just an extra thing to carry) .  

 

There may be times I will use MOGAS. (availability issue, winter, ) 

 

-glen

 

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Hi Glen - The test for the volatile components of fuels is called the Reid Vapour Pressure test.

RVP is different to True Vapour Pressure because of the methodology of the measurement process.

It's essentially a lab test,  and I do not know any company producing a portable, easy-to use test kit for RVP for fuels.

 

However, there is a slick portable device available, called ERAVAP, which does carry out "bench" testing of the RVP of fuels and oils.

However, this machine still rates as a piece of lab equipment, and could not be regarded as a "portable test kit".

 

The cost of an ERAVAP machine would be pretty eye-watering, and not the sort of thing you'd buy just to sit in your hangar and only use once a month.

 

The primary dangers in mogas are cheap, unauthorised, low grade additives by unscrupulous independent service station owners (paint thinners, toluene, etc), contamination by dirt and water via old underground tanks, and poor venting and sealing systems, and low fuel turnover by servos in areas where fuel sales are minimal. 

 

Accordingly, the best mogas comes from company-owned, new servos in high-traffic areas, where you see road tankers delivering fresh fuel every day or every couple of days.

 

The newer servos have fibreglass underground tanks that eliminate the corrosion problems of the old steel tanks.

Edited by onetrack
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1 hour ago, onetrack said:

Hi Glen - T................................................................

 

The primary dangers in mogas are cheap, unauthorised, low grade additives by unscrupulous independent service station owners (paint thinners, toluene, etc), contamination by dirt and water via old underground tanks, and poor venting and sealing systems, and low fuel turnover by servos in areas where fuel sales are minimal. 

 

Accordingly, the best mogas comes from company-owned, new servos in high-traffic areas, where you see road tankers delivering fresh fuel every day or every couple of days.

 

The newer servos have fibreglass underground tanks that eliminate the corrosion problems of the old steel tanks.

Glen - I would suggest that the need for a portable quality assessment tool is overkill - I have been using MoGas in my 912 for about 11 -12 years now, without any issues. I prefer 98 RON (probably psychological) but I am happy with 95 RON. As per OneTracks advice, I try hard to obtain my fuel from fuel providers that are well known brands, that appear to have a high turn over .

 

OneTracks advice is sound, if a little dated regarding the adulteration of fuel by "independent" servos (though they would be my last resort, coming after a top up with the penultimate AvGas) as fuel quality has improved markedly over the last 20 -30 years. I understand this to have been in response to Australia's need to meet the needs of the vehicle manufacturing industry, that in turn is under from overseas legislation to force them to higher standards of fuel econamy/pollution - lower quality fuel in makes for higher fuel consumption pollution out. Consistency of fuel quality allows for tighter "tuning" of engines so as to perform as expected.

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Skippy, as recently as 2016, 6 NSW servo operators were caught and penalised for mogas adulteration with Toluene.

 

There have possibly been more adulterated fuel prosecutions since, that I have not come across.

 

When you have tight fuel margins and very high prices for fuels, the potential is increased for shonky behaviour in the fuel retailing industry.

 

https://m.drive.com.au/motor-news/adulterated-fuel-sold-to-drivers-20100823-13gkx

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Hi ONETRACK 

thanks for the info on the ERAVAP machine.

I intend the run the Jabiru on AVGAS. 

 

But, I am interested in a closed loop monitoring  solution for MOGAS in general, a future planes would likely be  Rotax (relative insensitivity to fuel, overload clutch all useful features, useful power plant sizes) 

 

The EVARAP machine data is interesting. Need to know vapor pressure and octane.

 

I would think there would be some sort of litmus paper sample tester somewhere.

 

A poor man's  spectrometer isn't too hard either, but I am not sure if it would be able to see the volatiles with sufficient accuracy due to their low concentrations.  A couple of years of effort and it might go in a 3" instrument panel hole :-) 

 

-glen

 

 

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40 minutes ago, onetrack said:

Skippy, as recently as 2016, 6 NSW servo operators were caught and penalised for mogas adulteration with Toluene.

 

There have possibly been more adulterated fuel prosecutions since, that I have not come across.

 

When you have tight fuel margins and very high prices for fuels, the potential is increased for shonky behaviour in the fuel retailing industry.

 

https://m.drive.com.au/motor-news/adulterated-fuel-sold-to-drivers-20100823-13gkx

No matter what the law(s) is there will always be a criminal somewhere who thinks its okay to rip off the public - just part of life's rich tapestry I guess.

 

I still dont think the risk is significant, as long as the pilot follows your advice regarding purchasing from well known brand/high turn over outlets.

 

Its only the truly desperate & dim witted, that will knowingly supply bad fuel, as word will spread rapidly (Facebook/Twitter/etc) and they it will loose their local customers, for a long time, completely negating any windfall profits that they may have made Its not in the interest of  larger brands to supply dodgy fuel either, so I am happy not having a testing device other than the eye - colour and the nose- familiar "clean" smell and following your above recomendations.

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anyway, back to the topic.... !!!

 

There are a few near-infrared (NIR) transmission spectroscopy devices, handheld about. These are the spectrographic devices I mentioned.

They'll measure octane.  and provide volatiles info....CREA have one ,handheld... about 10kAUD$   K88600.

https://www.creapetrochem.com.au/fuels.html

 

An NIR spectrometer is one of those toys I will buy next year. we'll see how it goes. You can buy something suitable  for $2k-$4k...

 

 

Edited by RFguy
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Glen, it will take a long time to recoup your money if you spend $4k on a test gadget for mogas.

Jabiru say Mogas is ok but recommend avgas due to quality control issues.

My recommendation...... go with the Manufacturers advice, Avgas is readily available, change oil every 25 hours, examine spark plugs which are cheap to replace, and save the hassle of lugging around jerry cans of mogas which should be  used within 30 days or put into your lawn mower.

I know you will come across owners who swear by Mogas and say their engine runs smoother and cleaner, but for me, Not being Mechanically astute, I prefer to take advice from the Engine Builder and fill up with Avgas and plan my flights where I know Avgas is available

 

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2 hours ago, Roscoe said:

 

Jabiru say Mogas is ok but recommend avgas due to quality control issues.

My recommendation.... jerry cans of mogas which should be  well known providersor put into your lawn mower.

I know you will come across owners who swear by Mogas and say their engine runs smoother and cleaner, but for me, Not being Mechanically astute, I prefer to take advice from the Engine Builder and fill up with Avgas and plan my flights where I know Avgas is available

 

No offence Roscoe but -

  • I dont think this is a Jab/Other discussion its about making the use of ULP/MoGas safer using portable quality  a assessment devise (if a cost effective one exists at all??)
  • Jabirus comment (which I have heard befor) has all the hall marks of a, "cover all the bases/arse" & "sit on the fence" remark. Analyse it and I suggest you find: Its okay to use MoGas  & its okay to use AvGas. So in the proverbial "nut shell" Jab are saying the choice is the pilots/owner - all good  - no further debate.
  • Your final comment makes no sense as Jab (the engine builder) have already stated (according to you) that they accept both Mogas & AvGas - so good on you! you have decided to go with AvGas - no prob!
  • As for your "mogas which should be  used within 30 days or put into your lawn mower." - this Forum has hosted several extensive debates on this subject - it is now accepted (by most) that MoGas, stored in an approved, sealed container at above 70% (or was it 75%) capacity, has a shelf life of well over 6 months - may I suggest that you are doing a Donald on this matter.

.

 

 

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I need an NIR spectrometer for a genuine work  requirement.

 

And so if I can do MOGAS gas analysis, that would be handy also !

 

 

 

I think the MOGAS issues that are "loosely associated with Jabiru problems"  stem from the usual  high CGTs of air cooled engines (with respect to a water cooled heads)   and also due to imperfect mixture control leading to  ratios that produce high CGTs, and some stale fuel...... 

 

On a separate topic, if there is one small advantage of ethanol containing fuel I can see,  (and I am NOT suggesting  anyone run ethanol fuel in their Jab) is that the water in fuel tanks will get dissolved into solution (up to a point) and it wont sit in carb bowls.

 

(I happen to think the water test we all do is BS. IE , given that we're not always on level, how likely is the water going to be just above the drain hole  to the header, and it get down to the fuel test valve , even if the tanks are  swished around, While it is a useful procedure, I do not buy its effectiveness....   (hence the use of a Gascolator) .

 

 

 

 

 

 

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RFguy, Mogas has a higher energy content than Avgas (3-5%). If your engine is designed to use it, it will perform better with mogas than Avgas.

 

https://en.wikipedia.org/wiki/Avgas

 

 

 

DO NOT USE FUEL WITH ETHANOL. Ethanol dissolves water into solution. Under some circumstances it can reverse and dump that water into your engine. It also plays hell with your fuel system.

 

https://generalaviationnews.com/2016/10/24/ethanol-and-aircraft-just-say-no/

 

‘’As for fuel quality, do what others have advised and buy brand name fuel from busy outlets. Your concerns about contamination are not backed up by experience. Save your money.

 

I’ve had one deliberate contamination incident in fifty years and that was from a cut price no name retailer at peak hill, nsw thirty years ago.

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Walrus - we almost agree on every point (soo disappointing 😂).

 

Regarding ethanol:

 

Being a tad skeptical by nature, I dont use it BUT I would point out that Rotax have now approved up to 10% (E10) in their 912 range SUBJECT to the rest of the fuel system being ethanol compatible.  In this context the rest of the system is the tank and fuel delivery (hoses, pumps, etc) system.

I agree with your observations on water absorption and the need to be extra vigilant if using E10. In my most recent 5 year rubber replacement I made a point of ensuring the new hoses are E10 compatible - composite tank may not be however. This is not to enable my use of E10 but to reduce the chance of problems should some ethanol find its way into my fuel system.

 

Like you its been about 25 years since I experienced fuel adulteration, in my case diesel that smelt like paint thinners- and like you I had stupidly used a cut price  servo just outside Camden NSW. No lasting damage just lots of smoke & down two gears going up the hill to home. Drained tank as soon as I realised the problem. Never went back to that servo and 25 years later still tell the cautionary tail, so on going loss of custom to that business.

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14 hours ago, skippydiesel said:

No offence Roscoe but -

  • I dont think this is a Jab/Other discussion its about making the use of ULP/MoGas safer using portable quality  a assessment devise (if a cost effective one exists at all??)
  • Jabirus comment (which I have heard befor) has all the hall marks of a, "cover all the bases/arse" & "sit on the fence" remark. Analyse it and I suggest you find: Its okay to use MoGas  & its okay to use AvGas. So in the proverbial "nut shell" Jab are saying the choice is the pilots/owner - all good  - no further debate.
  • Your final comment makes no sense as Jab (the engine builder) have already stated (according to you) that they accept both Mogas & AvGas - so good on you! you have decided to go with AvGas - no prob!
  • As for your "mogas which should be  used within 30 days or put into your lawn mower." - this Forum has hosted several extensive debates on this subject - it is now accepted (by most) that MoGas, stored in an approved, sealed container at above 70% (or was it 75%) capacity, has a shelf life of well over 6 months - may I suggest that you are doing a Donald on this matter.

.

 

 

No offence taken Skippy, was just expressing my opinion and my views after reading about the pros and cons.

But your suggestion about DOING A DONALD ?..... bit harsh.

 

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True! true! - my craven apologies however that old urban myth about having to use MoGas within 30 days was debunked quite a long time ago now - but it must be in a gastight, fuel container & almost full to "keep" in good condition.

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Using Automotive Fuels in Aircraft Applications.

It’s been a long time since you could run out of fuel, pour in a bottle of whiskey and continue on as if nothing had happened.

 

Mogas is a US term for oil refined to gasoline; it’s refined for the US Market so taking information out of US media can be quite misleading, and using data from US engine manufacturers is also misleading if it’s based on US fuels.

 

 

Australian Petrol Standards

Fuel for petrol- engine cars in Australia is refined to meet Australian standards under two

Acts:

·        Fuel Quality Standards Act, 2000

·        Fuel Quality Standards Regulations 2019

and

·        Fuel Quality Standards (Register of Prohibited Fuel Additives) Guidelines 2003

 

The Australian petrol standards also take into account the substantial difference in operating temperatures between Australia and the USA.

 

Sulphur

Sulphur contaminates catalytic converters, and Australian fuels come from suppliers with higher levels of sulphur.

·        Permitted level in ULP: 150 ppm (parts per million)

·        Permitted level in Premium ULP: 50 ppm

 

Aromatic Content

Maximum 45% aromatics by volume, 42% pool average by volume.

 

Grades of Petrol in Australia

·        Regular ULP (Unleaded Petrol): Minimum 9RON  (Research Octane Number)

·        Premium ULP: Minimum 95RON (Some suppliers sell 98RON)

 

 

Grades of Ethanol/Petrol mix fuels in Australia

E10: 94RON with up to 10% Ethanol

E85: 105RON 70-85% Ethanol, 15-30% ULP 91RON (For compatible engines only)

 

 

Issues with Ethanol blends

Some engines are specified as Ethanol Compatible, but that doesn’t mean the fuel lines, filters and tank are. For that you have to consult the vehicle/aircraft manual, or build your aircraft with Ethanol compatible materials.

Where the engine is not designed for Ethanol, this fuel tends to eat into components, and if you are lucky pass them through the combustion system, but more likely block carburettor passages. Where you have non-compatible fuel lines filters, tank, a jelly will form in the bottom of the tank and material from this and the lines will also block the carburettors, so you will be subject to forced landings.

 

If you are unlucky, as I have been on several occasions this waste material will get into carburettor air galleries which have been blocked off at the ends in the manufacturing process, and you can’t get them unblocked. In those cases the only fix is a new carburettor (I’ve even tried boiling one for an hour).

 

Methanol race fuel causes similar problems and race procedure these days is after the last race, hook up a ½ litre can of petrol and run that through the engine, much the same as the old kerosene tractors where you would switch them back to petrol for the last couple of hundred yards.

 

If you want to run an aircraft on E10 or use E10 in it, you have to address this issue.

 

 

Issues with Aromatics

Aromatics don’t have the carby clogging issue, but they evaporate out of the fuel tank breather at a surprising rate.

 

I have a Chev 350 with fuel injection, and after a month without use, I can crank it as much as I like, and it won’t start. Add just one litre of Premium ULP, let the electric fuel pump et it up to the fuel injection, and it will start, about second kick. Not too convenient, but I couldn’t guarantee what’s happening to power output or the upper cylinder area.

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I kinda liked the term MoGas, bit classier than ULP and I didn't know MoGas was a USA term - will stop using it. 

 

I think you have overstate the E10/ethanol matter - it would be a rare pilot indeed, who knowingly filled her up with E10. Its potentially negative features would introduce an unnecessary element of uncertainty. From my perspective its the potential for ethanol contamination of 95/98 RON, so probably way less than 10%. To guard against this I have done all I can to make my fuel delivery system ethanol resistant.

 

You have made a good point about freshening, your potentially stale, in aircraft fuel. I am fairly sure that this has been a recommend practice in other conversation on this matter. I certainly top up with fresh fuel after my aircraft has been sitting for any more than a week - so far never had a start problem.

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Funny thing I can use a mower that has stood for 6 months and it starts straight away, but the fuel is probably 9 months old. Same goes for chain saws and whipper snippers. I have had problems with poor quality fuel in the Corby, near new and caused detonation, that was Caltex Super.

I have started engines that have been boxed for 9 years with fuel in the tanks, but it was not a certainty.

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Yenn - Reference mowers.chainsaws, etc - I am able to do the same. I assume this is because I use 91 RON (cant get 95 RON from my local servo any more) that has fewer volatile components and that in general these engines are lower compression.

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10 minutes ago, Yenn said:

Funny thing I can use a mower that has stood for 6 months and it starts straight away, but the fuel is probably 9 months old. Same goes for chain saws and whipper snippers. I have had problems with poor quality fuel in the Corby, near new and caused detonation, that was Caltex Super.

I have started engines that have been boxed for 9 years with fuel in the tanks, but it was not a certainty.

The starting problem is with Aromatics - Premium ULP (95 or 98RON)

 

The never start again/throw away problem is with  E10 in stationary engines including those you mention.

They'll usually start, but over time they suck up the jelly and detritus from the ethanol eating away at metal, rubber etc and it blocks the carby. If you're lucky ou can wash the carby out at put the air hose on it, but if the jelly gets into the closed air galleries and dries out it bakes on to the walls and the only way to get the engine running again is fit a new carby.

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