Rotax 912 UL with Opal Fuel - Remote Communities

[Xavier]

Hi,

 

Living in Darwin and having connections in Arnhem Land, I intend to travel there quite a lot, unfortunately, most of the time, the only fuel available is the "Low Aromatic" Opal fuel.

 

WIKI

 

It is rated 91 RON so it should be ok for the 912UL.

 

I tried as much as I could to find some information about the use of "Low Aromatic" Opal fuel in a Rotax 912 (UL) but unfortunately I could not find if using it will damage the engine or will impact on the performances of the engine.

 

I don't intend to use it all the time, only to fly while in Arnhem Land (4-8 hours) and to come back to Darwin (3 hours), once in Darwin I will use the Vortex 95 again.

 

Looking forward to hear your advice or to guide me to a website where they talk about it.

 

My apologies if this subject has already been covered.

 

Xavier

 

 

[bexrbetter]

PM rv6ejguy here or at HBA

 

http://www.recreationalflying.com/members/rv6ejguy.11116/

 

 

[Halden Boyd]

Hi Xavier,

 

Being a pilot and of Kooorie descent it might be an good idea to contact the NT Government Transport Department or CASA. I have never flown in NT, however, communities there are given LL Avgas and cars are converted to this. The reason is the huge problem with adults and kids petrol snifffing, and they cannot get "high" with the LL product.

 

Maybe RA-Aus can expand on this and help you out as well. Otherwise you might have to upgrade to a 914....

 

Cheers brother...

 

Halden

 

 

[kaz3g]

This is a question that interests me also.

 

My understanding is that the early unleaded replacement for remote communities was just straight a gas. Then Opal was produced as a manufactured alternative which is not popular with vehicle owners because of running problems.

 

A gas is now rare on the communities as most aircraft servicing them now run avtur.

 

Any info appreciated.

 

Kaz

 

 

[ben87r]

Where abouts an exactly would you be heading? Ive mostly come across Opal further south in the Alice region, there is also Avgas at Borroloola, Groote, Ngukurr, and a few other spots, all but Groote needing prior permission/Local fuel card

 

 

[Xavier]

I would be heading to Central Arnhem Land : Ramingining - Maningrida - Gapuwyak - Bulman, around the Arafura Swamp.

 

The main community I will be flying from will be Ramingining.

 

If I stay there for a week and fly everyday, I won't have many choices :

 

- Using the local Opal fuel

 

or

 

- Bring ULP95 there by road in advance and store it safely at a mate place, but I am not really keen to let it sit for 3-4 months

 

 

[facthunter]

I agree with Kaz. Originally Opal fuel was avgas. It is probably subsidised as it has a lot of things eliminated from it. I recall it being mentioned in parliament . It isn't talked of much. I think it is a "quality product" and if the Octane rating is OK It would be better than mogas. The 100 HP Rotax needs a higher octane than the 80 HP, I recall. Nev

 

 

[ben87r]

Well there is AVGAS at Maningrida but, like you said if you are staying a while might be a lot of travelling to get fuel.

 

In regards to the origional question, don't know bugger all about the fuel but, my car I had there didn't seem to like it. I got around 15% less KM to a tank when I was in Alice.

 

 

[facthunter]

That might be because it is hard to get a parking spot there unless you are very quick.. Nev

 

 

[facthunter]

On reconsideration of this I would approach the producers. They should have a Product Data Sheet or whatever it's called. It may be a little political, but since it's an aviation matter I would clear it up.

 

I know they are always busy, but it should be a matter the RAAus deal with. (and CASA). Nev

 

 

[Russ]

Vev.....poster here, shoot him a mail, he's got the answers.

 

 

[Birdseye]

Try this link for background.

 

http://www.bp.com/en_au/australia/products-services/fuels/opal-fuel.html

 

 

[facthunter]

Based on that I wouldn't use it in the 100 hp motor without improving the octane, by adding something. Nev

 

 

[Birdseye]

My understanding is that the deterioration issue for avgas in a vented tank is in part the loss of aromatics. I know most motorbikes don't like Opal, unless they are one of the very few that have an ignition retarding capability - Quote: "Opal low-aromatic fuel"

 

 

[facthunter]

I didn't think avgas had aromatics, but I'll take advice on that. The initial OPAL was related to avgas, or that was the original concept. Of course it wouldn't have the lead I expect. It's not as complex as Mogas where anything that will combust goes into it almost. I think the low aromatic statement is in relation to conventional mogasNev

 

 

[Xavier]

Hi all,

 

it hasn't been easy to find some information about Opal fuel but after talking to 4 recommended qualified person with a lot of experience in aviation, I have been told by all of them that it is suitable for a 912UL.

 

Apparently the quality of Opal fuel has really improved, one person told me that it can help to use an Octane Booster and another one told me not to so this part is still unknown

 

I talked to the local Yamaha boat shop in Darwin who has customer using their 4 stroke outboard in remote communities using only Opal fuel.

 

They told me there is no problem with Opal fuel.

 

They told me that some time they recommend using "Yamaha Ring Free" to keep the engine clean when using Opal Fuel.

 

Any other feed back on Opal fuel is welcome.

 

Also, what you guys think about using "Yamaha Ring Free" on their Rotax 912 ?

 

Some links :

 

https://yshop.yamaha-motor.com.au/products/ring-free-fuel-additive-0

 

http://yamahaoutboards.com/sites/default/files/images/Ethanol_Fuel_Flyer.pdf

 

Cheers,

 

Xavier

 

 

[Russ]

Avgas 100LL is around at quite a few communities, it's well and truly under lock and key, but....you can get it, by prior permission ( current stock situation )...often drums, be aware. ( Be super nice when you call em......trust me, otherwise you're p!ssin in the wind )....O yea.....don't push for a tank load, enough to get you to proper outlet.

 

Have gained LL several times remote locales.......remember.....be nice.

 

Ol mate petro guy.........says avoid octane boosters in general.

 

 

[Birdseye]

Xavier, your own post confirms that Opal fuel is not appropriate, at least not without modification. For example "it can help to use an octane booster" and recommend using "Yamaha Ring Free".

 

I don't know what constitutes a "recommended qualified person with a lot of experience in aviation", but perhaps its like "a mate down the pub that flys a lot".

 

I'd prefer to go by the Rotax operator's manual (and legally should as well I believe):

 

Page 2-9

 

912 S/ULS

 

Min RON 95 or 100LL Avgas

 

The manufacturer of Opal states that it is not a minimum of 95 Octane (RON scale) and therefore it isn't suitable. Unlike an outboard motor, you can't bring out the paddle when the motor stops.

 

 

[facthunter]

It's in black and white. 95 octane. Taking off is rarely a life saving necessity in a Recreational Aeroplane.

 

LANDING is.. Brewing up something is possible but not the right thing to recommend out there in a general sense. Nev

 

 

[Russ]

I've said it somewhere here ??......ol mate, petro guy, said for ??? reasons, they ( refinery ) rate the stuff at 91, but it's a lot HIGHER.

 

 

[Xavier]

I own a 912 UL, it requires min RON 91

 

http://www.flyrotax.com/enginesImpressum/product-rangeImpressum/carburetedImpressum/912-80hpImpressum/engine-data-performance.aspx

 

"recommended qualified person with a lot of experience in aviation" :

 

--> One L2 at my airstrip gave me 2 names to contact, I have also e-mailed Bert Flood.

 

The last one is someone on the forum who work in the petroleum industry

 

It has been very hard to get some good info about Opal fuel and no it wasn't at the pub

 

 

[facthunter]

It may be so, but IF it rated 95 why wouldn't they say so?. As I said in one of my posts it is somewhat sensitive and very political. ROTAX say what it should be (as a minimum) and I reckon the makers are saying OPAL is 91 (as a minimum). Are you prepared to put your house on the line where the fuel companies won't. There are plenty of vehicles that 91 is not good enough for. Just using it and getting away with it, for a while, doesn't cut in a court of LAW.

 

The 80 HP engine is OK on 91. This is from Rotax which at the end of the day will be the bible.Nev

 

 

[Russ]

Vev..............where are you mate, sort this..........again. ( won't ask you again, promise )

 

 

[facthunter]

Vev would know, but what's the problem? 91 for 80HP and 95 for 100 HP. Any fuel either makes it or it doesn't although with mogas there is no guarantee after it leaves the refinery. All aviation fuel has release notes and you sign for it. A 44 gallon ( 206 litres) once opened isn't legal once it's just been sitting around. Nev

 

 

[Russ]

i've got no problem......ol mate here (Darwin ) seems to be getting mixed info, re opal......hence..........VEV.

 

91...95, into rotax ??? i'm not concerned about that aspect.