Jabiru Oil

[Relfy]

I've taken this from the Natfly News post because I feel it deserves it's own area of the forum.

 

Bubbleboy said:

 

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Shell has advised that the usual oil (sorry cant recall) should not be used anymore as due to the small amount of oil in the Jab engine, it becomes contaminated with lead very quickly when using Avgas.

 

Scotty:coffee:

 

Q to anyone that was there - I had to leave half way through: The 'usual' oil is Shell Huile Aviation 20w-50w. Did Keith mention an alternative?

 

Chris Stott

 

Come and visit us at Central West Flying School www.centralwestflying.com

 

 

 

Does anyone have any further information as to what is now recommended in place of the Shell Oil?

 

 

 

Regards,

 

 

 

Relfy

 

 

 

 

 

 

[Guest Andys@coffs]

Yep, have to say that post triggered my attention. I'd also like to know what is it about the shell oil that is any different to any other form of oil.

 

Is this a "liability" reduction exercise on the part of shell, or is there a fundamental deficiency.

 

I'd like to hear of jabiru's take on this

 

Andy

 

 

[facthunter]

They make a range of aviation oils that cope with lead. Don't Jabiru recommend the aeroshell multigrade? Nev..

 

 

[Dieselten]

Shell says use W100 in Jabiru engines. Jabiru says use 15w50 multigrade in Jabiru engines.

 

"Rock and Hard Place" seems to sum it up for me.

 

The issue is degradation of the lubricant additives by lead in engines running Avgas and the multigrade oil. In large oil-capacity engines (Lycoming, Continental etc) this is not so much of a problem due to the sheer volume of oil on hand, but in a small capacity engine (Jabiru 2200 and 3300) the oil degrades the additives relatively quickly. Shell are saying this doesn't occur in the W100 oil, although it is still a dispersant oil.

 

One option is to change the oil more frequently (say every 25 hours instead of every 50)...or go with the W100.

 

The other option is not to use a Shell oil at all. There are others.

 

 

[facthunter]

multigrade oils have "polymers" to modify the viscosity index( Reduce the thinning of the oil with temperature rise).. They do wear out but I would suggest that the relatively short drain times we use, there would not be a significant problem. Coping with the lead residue would require some sort of additive and as it is used up it would become less effective. As far as I can gather AERO oils would be the only oils that have additiives for lead so they would be the ones that I would use in the Jab which runs on 100LL. A monograde being a fairly thick oil would require more warm up. Jabiru originally recommended the multi-grade for cooler climates but then made that recommendation more or less universal.

 

All aero oils have to meet a minmum standard so all of them would be a reliable product . I can't remember an engine failure where the oil was the cause quality-wise. There may be more high performance oils on the market but I wouldn't go there if running on avgas. The Jabiru is not a highly stressed engine and there is no reason why it would need an oil different from a lycoming.

 

The Rotax is a different matter because of the gearbox using the same oil. Nev

 

 

[Vev]

I was at Keith's presentation too and was a bit surprised to hear this claim .... I'm not sure I can reconcile this in my own mind as I know Aeroshell has a solid pass on the Mil-L-22851 and the new replacement spec SAE-J-1899 which must have lead capabilities to obtain this approval. Completely agree with D10, 25 hour oil changes will take care of a multitude of sins, including lead compounds.

 

I wonder if there could be some confusion with Aeroshell Sport 4 Plus product? It is also a multigrade 10W-40 but only has an API SL rating which would suggest it will have lead capabilities but only from an obscure old engine test from the 1970-80's, which isn't going to be a strong lead recommendation in Shell's eyes. Of course the Sport 4 cannot be used in the Jab as it is really designed to work in the Rotax and carries the JASO MA spec for wet clutch motorcycles which reads across to Rotax's gearbox/clutch set up.

 

I will give Shell a call and have a chat to them and see what they have to say.... I will post when I hear their story.

 

Cheers

 

Vev

 

 

[Vev]

I spoke with Shell today and they are very much in support of Jab's recommendation of the 15w-50 Multigrade ... the lubes techo I spoke with can see no reason to be concerned about lead or any other normal combustion contamination in their lube.

 

He also pointed out that chemistry of the product and it's qualifications meet everything one would expect to see in a lube designed to be used with Avgas.

 

He also went on to say, until Jab could convince them otherwise the multigrade will remain as Shell primary recommendation for Jabiru aircraft engines.

 

Cheers

 

Vev

 

 

[Relfy]

Good work Vev, sounds like I'll stick to the Shell Oil. Does anyone here actually wait until 50hrs to change the oil? I change mine every 25 and even by then it looks pretty 'worn'. I'd hate to see it at 50hrs...

 

 

[Steve Donald]

Good work Vev, sounds like I'll stick to the Shell Oil. Does anyone here actually wait until 50hrs to change the oil? I change mine every 25 and even by then it looks pretty 'worn'. I'd hate to see it at 50hrs...

because of trips overlapping my 25hr changes i have averaged 17hr changes, it is only a bit over 2 ltrs and gets a beating oil is cheaper than spanners keeps the internals very clean, drive em hard keep the oil fresh and service per the manual, stay up to date with the factory recommendations they told me about the shell 100 plus may be the go now, yesterday, so watch this issue from the factory advisory not shell agents as they are conflicting with advice, shell advised Jabiru about the 100 plus. and 25 hrs is max 50 is destruction just like cold oil changes are, hard to believe but dudes do it. And keep the prop in perfect track and balance the energy there is tons on that disk, it seems to be the most overlooked item that provides the performance on your aircraft. i have seen some really bad props, done a balance and track and the owners have been amazed at the difference like i can see the gauges clearly now as they were blurry, yep like Tyres on your car slowly wear until you have new ones you don't really notice; you get used to your environment, i do a prop check each service it is easy and just a bit of time and is kind to the airframe and crank and so on a chain reaction occurs, but hey this is only my view from what i have been told over the years from experienced aviators, and what i have experienced personally i hope this is helpful for some.

 

 

[pudestcon]

i do a prop check each service it is easy and just a bit of time and is kind to the airframe and crank and so on a chain reaction occurs, but hey this is only my view from what i have been told over the years from experienced aviators, and what i have experienced personally i hope this is helpful for some.

How do you do the prop check Steve?

 

Pud

 

 

[Steve Donald]

How do you do the prop check Steve?Pud

for tracking set all the hub bolts midrange tightness, place a static marker a telescopic antenna is good behind the blade you can tape to a stand of any sort, the antenna can be extended to a point where it just touches the trailing edge of the prop about 40 mm in from the tip is ok, carefully rotate the prop to the next blade if your lucky it will be the same however if the gap is wider that is the high blade, just add an extra 1 Ib tighter on that half of the hub and check again, the balance check should be done prior to all of that and is better explained off the net Brett Thompson propellers website has some good tutorials on there and diagrams ect, if ever you get a chance to get a dynamic balance done cost about $100 it is done on the plane running with spinner on i intend to get my own balance machine in time does a great job. hope this helps cheers

 

 

[Steve Donald]

How do you do the prop check Steve?Pud

for tracking set all the hub bolts midrange tightness, place a static marker a telescopic antenna is good behind the blade you can tape to a stand of any sort, the antenna can be extended to a point where it just touches the trailing edge of the prop about 40 mm in from the tip is ok, carefully rotate the prop to the next blade if your lucky it will be the same however if the gap is wider that is the high blade, just add an extra 1 Ib tighter on that half of the hub and check again, the balance check should be done prior to all of that and is better explained off the net Brett Thompson propellers website has some good tutorials on there and diagrams ect, if ever you get a chance to get a dynamic balance done cost about $100 it is done on the plane running with spinner on i intend to get my own balance machine in time does a great job. hope this helps cheers.