Microlighters

The talk in the town is that leaded petrol will be phased out in the near future!

What does this mean for a aircraft owner with a Rotax503...?? Will I need to convert something or can I just change from leaded to unleaded??

Hey Smiley

I have always run my Rotax on uleaded, so should not be a problem..just switch over.

Yeah.. dont sweat it, changed over to 95UL about 12 months ag.. no difference I can tell

Smiley,

remember, leaded fuel is used in older cars to lubricate the valves. The 503 and 582 do not have valves. Additionally the motor was designed in Europe, where the use of leaded fuel has been out of fashion for many years and was in fact designed to be used for unleaded and not leaded environments.

Thanks guys!!! :D :D

Smiley wrote:The talk in the town is that leaded petrol will be phased out in the near future!

What does this mean for a aircraft owner with a Rotax503...?? Will I need to convert something or can I just change from leaded to unleaded

Hi Smiley,

Smoke emission became a big issue in Europe and the USA about 8 years ago. Consequently, catalytic converters [incorporating platinum from SA] became a production requirement in new motor vehicles.

Leaded fuel will damage a catalytic converter by chemically reacting with the platinum – hence the introduction of unleaded fuel.

Engines without a catalytic converter [fitted in the exhaust] can therefore be operated with both leaded and unleaded fuel. Just minor differences in octane ratings to consider.

Hope this helps - regards

With the new 4 strokes the oil change period is reduced with leaded fuel, the HKS has a strong warning about regarding the use of leaded fuel and its effect on oil change intervals. You can use avgas but chabge the oil sooner. Two strokes do not require lead as a previous respondent stated.

Lead has been used in fuel to boost the octane rating and with the phasing out of lead, some fuel companies started using MMT which contains manganese to boost the octane. This was also phased out as it's also a 'heavy metal" and manganese is just so unstable.

Almost all unleaded fuel contains alcohol, to boost the octane, in SA the content is between 8 and 12%, I stand to be corrected.

Alcohol is hydroscopic, it loves water!

Store fuel in metal jerry cans.
DO NOT use plastic containers.
get your fuel from a station that is fairly new, busy and that turns it fuel over regularly.

Fuel that is stored over long periods of time - the alcohol dissipates, thus reducing the octane rating. This may cause some substantial damage to your engine.

My rule - If you are in doubt of the quality of the fuel, wherever you may be, use AVGAS if available.

Regards
Niren

I think what our gud frend Niren is really saying here is .. if its good fer engines then.. we should be boostin our 'octane' levels, so im all for fighting to avoid dissapation of our alcohol levels - and god forbid heed the gud advise and dont be puttin any water to the precious stuff now - besides ah cant cee how anyone could store the stuff fer any length of time - can yu

oh and while yer at it boyos, don't ferget to put some lead in the ol pencil now -


ACCEPT NO SUBSTITUTES

Thanks Niren

The following mail was also circulated to all SAGPA Members.

A Number of engines that have been brought into the various aircraft and engine service centres recently, have showed signs of premature engine wear or damage that may have been caused by low grade or contaminated fuel.

Although it is sometimes difficult to pinpoint the exact cause, burnt valves, spark plugs and other internal damage seems typical of the type of damage caused by detonation. As too low octane or contaminated fuel is one of the known causes of that sort of damage, I would again like to urge everyone to be careful in selecting the fuel used for your aircraft.

Unleaded fuels typically have a lower octane rating, and some of the modern environmentally friendly additives used to boost octane, also degrade quicker than those used in the past. It is impossible to ascertain the octane levels of every tank of fuel, therefore it is important to use the highest octane fuel available in your area and refuel from a reputable supplier that has a high turnover in fuel. Also use the fuel within a couple of weeks, do not let is stand unused for months and then use it to refuel your aircraft.

Bigger service stations have 95 octane (inland) and 97 octane (coast) unleaded fuel available at about a 2% price premium. It should make sense that the little extra paid for the fuel, is easily offset for the peace of mind and reduced wear on the engine.

The colour of the fuel, engine temperatures, spark plugs condition and general behaviour of the engine can also be early indicators of an engine that may potentially be affected. If unsure, contact your nearest service agent or approved person for another opinion.

Have a look at www.sagpa.co.za/Articles/14/59.php for a rough guide to spark plug colours on an engine.

Invaluable inputs - thanks everyone!