Fuel treatment?

[planedriver]

Having over the years seen many aircraft just sit in hangers for "God knows how long" between flights, but obviously still with fuel in their tanks. I was wondering whether additives such as StaBil and similar products, would be beneficial additives to put in aircraft fuel, to prevent it going stale if the aircraft only has occasional use.

 

I know with my boats if they've gone for many months without use, the fuel tends to go off.

 

Many outboard motor manufacturers actually recommend it, and I was wondering if aero-engine manufacturers are the same.

 

 

[storchy neil]

I would not put any additives into any fuel for aircraft i have a feeling rotax warned against same

 

any aircraft engine that is not going to be used for a period must have inhibitor i think that's the word or run to operating temp every so often neil

 

 

[cheyenne]

Their was a plane in a hanger at Bundy that had not been started for at least 10 years, The fuel in the tanks was avgas, it was tested and found to be OK, the engine was boroscoped and then started on about the third rotation, all the fuel hoses leaked but it ran.

 

 

[Guest Andys@coffs]

Engine manufacturers have a section in their manuals that deals with storage and what must be done. Jabiru for example needs a special oil inserted and the crank rotated every week during storage........

 

The extract from the J manual:-

 

6.2.1 Flyable Storage

 

 Flyable storage is defined as a maximum of 30 days non-operational storage.

 

 Ensure that the engine has been stopped by turning off the fuel valve, thereby not leaving any fuel in the carburettor bowl.

 

 Every 7th day the propeller should be rotated through 5 revolutions, without running the engine. Leave the propeller in the horizontal position to ensure even distribution of liquids in the wood. If left in the vertical position, liquids will drain to the lower tip resulting in an unbalanced propeller.

 

6.2.3 Temporary or Indefinite Storage

 

 Temporary storage is defined as engine in non-operational status for a maximum of 90 days.

 

 Treat as for flyable storage, plus:

 

- For temporary storage, fill aircraft fuel tank with AVGAS (to prevent moisture accumulation).

 

- For indefinite storage, drain fuel tank, ensure carburettor bowl is empty by running engine with fuel valve off until it stops or by draining bowl.

 

CAUTION

 

Do not store MOGAS or fuels containing alcohol for longer than 30 days in a Jabiru aircraft. Refer to Service Letter JSL007 for details.

 

Then:

 

1. Clean engine thoroughly.

 

2. Seal or cover all openings.

 

3. Remove battery and store in a cool dry place. Service the battery periodically and charge as required.

 

NOTE: It is recommended that batteries not being used should be charged every 30 days.

 

4. Disconnect spark plug leads and remove spark plugs from each cylinder. Using an oil can or spray atomiser, spray preservative oil through a spark plug hole of each cylinder with the piston in the down position. Rotate the propeller 10 – 12 times, leaving it in the horizontal position. When all cylinders are treated leave prop horizontal and retreat each cylinder.

 

NOTE: Use SHELL Aero fluid 2UN (MIL-C-6529C Type 1) or similar engine corrosion inhibitor.

 

5. Install spark plugs and connect leads.

 

6. Seal exhaust pipes. Attach a red streamer to each.

 

7. The fuel tank breather must be covered but MUST NOT be sealed – the expansion of gases within the tank can severely damage it if there is no escape path.

 

8. Attach a warning placard to the instrument panel stating that vents and breathers have been sealed and that the engine must not be started with the seals in place.

 

9. Every 7 days the propeller should be rotated through 5 revolutions without running the engine – leave propeller in the horizontal position.

 

CAUTION

 

Ensure that the Master and Ignition Switches are OFF before turning motor!

 

I can tell you from first hand experience that not doing this is very expensive!!!!

 

The thing with J engines is that the barrels are steel. Others such as Rotax use a ceramic coating such as nickersil (SP??) over a barrel material that isn't steel to prevent the corrosion issues that you can see with J. However the barrels are only one point of corrosion in an engine and I think that the issue here is to ensure that as much as possible moisture is kept out of the engine by ensuring that it is at operating temp and has been for some time when you shut it down (a quick ground run is unlikely to meet this requirement) and that all sources of entry for air with moisture to the innards of you engine are shut off with blanking plates/covers

 

Im told that J are very close to replacing the steel barrels with something that doesn't have the corrosion issues...but as is always the case with J a change such as that is generally prohibitively expensive to just retrofit all existing.....and in any event being at the bleeding edge with J might require bleeding! I'll let others test version 1.0 of a new solution

 

Andy

 

P.S I guess your location in Australia will to some extent mitigate or exacerbate the corrosion issue. In Adelaide especially away from the coast corrosion was a non issue......In Coffs where I am now, you can almost hear things rusting it happens so fast compared to Gawler in SA....

 

 

[David Isaac]

I have heard of guys running super two stroke oil in their fuel normally. I have heard stories that it provided exception bore coating when the engines are not operated for extended times. I am not sure of the implication on aero engines and I would value Nev's opinion on this.

 

It is also a common practice for Diesel engine operators to run the STS oil, especially in the common rail hi pressure systems today. The fact we run low sulphur diesel fuel which has a significantly lower lubricity than the older fuels we used to run is the main reason. I run Valvoline TC-W synthetic oil at a ratio of 200:1 in my V8 turbo diesel Troop carrier and it is highly recommended by cummins and ford operators as well because it extends the service life of the injection systems and the engine 1,000,000 Klms plus. Given my injectors are around $1,000 each and there are 8 of them, I consider it cheap insurance

 

 

[facthunter]

Nice to see a comprehensive coverage of the storage requirements for the Jab. Steel cylinders are the most common feature on MOST aero engines . Some are nitrided (surface hardened) and some are not. I don't think it changes the rusting aspect. You should be aware of the need to be concerned about engine corrosion in storage whether you live coastal or not. The water that is needed to form corrosion is there from the products of combustion. The fuel is a hydrocarbon which is something like C7H14. the hydrogen combines with oxygen to form WATER H2O which mixes with other things around to form some acids that rust the cylinders unless you do something to stop it. A coat of corrosion inhibiting oil is a good way. If you are going to leave the engine sit, it would be a good idea to drain and replace the oil in the engine with fresh and do 3or4 circuits at least to FULLY warm it, and then do the Jab treatment. I would run the fuel out of the carb at a high idle speed too. If you don't normally do this PLACARD the dash, but with a drained bowl the engine is not likely to fire up, but if you are unlucky the fuel tap may leak and allow the bowl to fill. Nev

 

 

[planedriver]

Many moons ago, I use to have a Red- X "Lubro-Charger" filled with Red-X. (Upper cylinder lubicant).

 

Prior to shutting down the engine, you'd hit the button, and 2cc of upper cylinder would be squirted into the inlet manifold, leaving an oily film on the cylinder walls to prevent wear on start-ups.

 

I thought it it was great at the time and swore by it for years, but as the years roll by, and the young-uns know the answers, i'll wait to be advised by those that know:cheezy grin:

 

 

[David Isaac]

Nev,

 

Can you comment on planedrivers use of redex and my comment above about using super two stroke oil as a fuel additive in aero engines such as Cont and Lyc and my Gipsy Major please.

 

 

[facthunter]

All a good idea if you can ensure the oil is distributed evenly. It could end up in one cylinder unless it is finely atomised. I like to keep planes simple. The more you have the more to go wrong. If someone made an aerosol can. WD and motor the engine on the starter with wide open throttle might do it on the Gypsy, or anything where you can access the intake easily. Don't put it through a paper element aircleaner. Nev

 

 

[Gnarly Gnu]

Planedriver I also heard Sta-bil is pretty good & was looking for some to use in the generator at work but it seems very expensive here.... got a cheaper or bulk source? Is it just the 'Australia tax' again?

 

 

[AVOCET]

Marine mogas , ?

 

Please give more info

 

Mike

 

 

[AVOCET]

Thanks for that , I'm using bp 95

 

Cheers mike

 

 

[AVOCET]

Now that you mention this , what do marine people use ?

 

Might be worth talking to and finding out their supply of ethanol free!

 

 

[dazza 38]

Mike. BP 95 is Bowser marked as Ethanol Free. Stay away from Shell and Caltex. Cheers Don

I don't know why you have it in for Caltex, anyway the ONLY unleaded fuel with ethanol in it, is their E10 blend. Caltex vortex 95 and 98 DO NOT CONTAIN ETHANOL .Just because Caltex decided to removed their Ethanol Free stickers back in around 2005, doesn't mean they all of a sudden started putting Ethanol in their premium fuels. They removed the stickers because they decided it wasn't needed as they CLEARLY LABEL every (e10) bowser to say that it is a ethanol blended fuel. They even mention on their own web site that various engines eg- outboards, ULTRALIGHT engines etc should not use E10 but use the premium fuel which is Ethanol free.

 

 

[AVOCET]

I found c/ tex 98 has a lot of aromatics and it made my fuel lines soft !

 

95 still has aromatics but not as much .

 

I can smell the fuel through the pirtec fuel lines on the multipoint SDS

 

But on the rotec TBI the red silicon lines are ok .

 

Mike

 

 

[Downunder]

I found c/ tex 98 has a lot of aromatics and it made my fuel lines soft !95 still has aromatics but not as much .

I can smell the fuel through the pirtec fuel lines on the multipoint SDS

 

But on the rotec TBI the red silicon lines are ok .

 

Mike

Funny you should talk about the smell.

My cockpit reeks and I've taken to leaving the doors ajar.

 

I wonder if I use 95 (currently 98) the smell will be the same?

 

 

[Dafydd Llewellyn]

Maybe there's a reason why Cessna etc don't use flexible fuel line where it's not necessary. The alternative is to get yourself a 37 degree flare tool and use aluminium tube, in accordance with FAA AC 43.13-1. You need to learn about AN hydraulic fittings; the aluminium (blue) ones are OK outside the engine fire zone. Inside the engine fire zone, use steel fittings (the JIC series are compatible with 37 degree flare, but they are not cheaper than the AN steel fittings, in my experience. For fuel containing alchohol, use stainless steel fittings in the fire zone). This option is much more labour-intensive, but you only need to do it once, and you won't be poisoned by the aromatics etc that leach through flexible lines. If you're getting fuel smells through your flexible lines, this means the plasticisers in the lines are being lost; the lines will become brittle. Flexible lines do not have an indefinite life. Use them only where relative motion exists, e.g. between the engine and the firewall.

 

 

 

[Downunder]

Maybe there's a reason why Cessna etc don't use flexible fuel line where it's not necessary. The alternative is to get yourself a 37 degree flare tool and use aluminium tube, in accordance with FAA AC 43.13-1. You need to learn about AN hydraulic fittings; the aluminium (blue) ones are OK outside the engine fire zone. Inside the engine fire zone, use steel fittings (the JIC series are compatible with 37 degree flare, but they are not cheaper than the AN steel fittings, in my experience. For fuel containing alchohol, use stainless steel fittings in the fire zone). This option is much more labour-intensive, but you only need to do it once, and you won't be poisoned by the aromatics etc that leach through flexible lines. If you're getting fuel smells through your flexible lines, this means the plasticisers in the lines are being lost; the lines will become brittle. Flexible lines do not have an indefinite life. Use them only where relative motion exists, e.g. between the engine and the firewall.

Would love to..... I have the knowledge and ability but it's a "24"......

 

 

[Dafydd Llewellyn]

Yes - well, that's one of the ways manufacturers make those aircraft "affordable". Here's the collector tank for the Blanik engine conversion:

 

 

 

[robinsm]

I have used Caltex exclusively after being warned away from BP and Shell about 9 years ago when I built my aircraft. I test the fuel (95 and 98) all the time and have not had any problems. I use flexible fuel lines and have not had any degrading in that time (haven't changed them either and they are still flexible. (one of the "experts " at Natfly a couple of years ago gave me the benefit of his vast experience and told me I should change the fuel lines every 2 years or ..."you will be sorry one day"...) The fuel lines are blue plastic and mostly mounted externally. I have fibreglass tanks. I use oil injection in the 2 stroke motor and use a mineral oil. I was told that if the aircraft is going to be sitting for extended periods then the mineral oil sticks to the upper cylinders better than the synthetic types. So far no problems. Just my 0.2c worth...

 

 

[Dafydd Llewellyn]

I have used Caltex exclusively after being warned away from BP and Shell about 9 years ago when I built my aircraft. I test the fuel (95 and 98) all the time and have not had any problems. I use flexible fuel lines and have not had any degrading in that time (haven't changed them either and they are still flexible. (one of the "experts " at Natfly a couple of years ago gave me the benefit of his vast experience and told me I should change the fuel lines every 2 years or ..."you will be sorry one day"...) The fuel lines are blue plastic and mostly mounted externally. I have fibreglass tanks. I use oil injection in the 2 stroke motor and use a mineral oil. I was told that if the aircraft is going to be sitting for extended periods then the mineral oil sticks to the upper cylinders better than the synthetic types. So far no problems. Just my 0.2c worth...

Well, that's interesting; maybe you've got lucky with the fuel line. If it's a polyurethane type, I'd expect it to last longer than some of the other grades. But with aromatics in the fuel, who knows what the situation will be from day to day. Goulburn's pretty cool most of the year; that would help, too. Given the problem with composite fuel tank sloshing compounds, I think I'll stick to welded aluminium tanks and aluminium fuel lines, at least outside the engine fire zone.

 

 

[AVOCET]

Funny you should talk about the smell.My cockpit reeks and I've taken to leaving the doors ajar.

I wonder if I use 95 (currently 98) the smell will be the same?

I think the 95 doesn't stink as much as the 98 , but ive found that it doesnt smell through the red silicone hose ,

The flexible hight pressure hose seems to be the issue ,

 

Has any body heard about the 100 no led for aircraft use ?

 

 

[geoffreywh]

I have left (this year ) mogas in my tank for 16 weeks with no ill effects. ( BUT not in the carb!) If you care to check, Japanese motorcycle fuel lines are ok at 20 years plus. No hardening , no cracking. It's available from wholesalers. BUT it's black.......

 

 

[Dafydd Llewellyn]

I have left (this year ) mogas in my tank for 16 weeks with no ill effects. ( BUT not in the carb!) If you care to check, Japanese motorcycle fuel lines are ok at 20 years plus. No hardening , no cracking. It's available from wholesalers. BUT it's black.......

Do you have a specification for it?

 

 

[dazza 38]

I have left (this year ) mogas in my tank for 16 weeks with no ill effects. ( BUT not in the carb!) If you care to check, Japanese motorcycle fuel lines are ok at 20 years plus. No hardening , no cracking. It's available from wholesalers. BUT it's black.......

My KTM motor bike has the original fuel line and it is 11 years old. Looks like new.