What grade of oil to use in a Jabiru J170?

[Vev]

[quote="turboplanner, There's no problem at all with deciding to change oil earlier than the manufacturer's recommended intervals, but it can be expensive depending on the oil cost. In the example of a certain 4x4 I gave earlier, changing at 25 hours would cost $7,200.00 by the end of 200, 000 km.

 

Oil Analysis is an alternative to this, since this shows when the oil is starting to break down and need replacement, rather than just being discoloured.

 

Hi Turbs,

 

I'm not completely aligned with your alternative suggestion in using oil analysis on economic grounds. In this context, a Jab 2200 engine only hold 2.2lt (really only 2lt) oil lubricant and costs about $30 to do an oil change. The most basic oil analysis will cost a min of $25 to Joe Blogs in the street and more likely $50. It's in my view, it is far cheaper to just change your lube earlier and a whole lot more convenient, as you are not waiting on the return of the results to make a call.

 

In reality base oils only break down when subject to extreme use, that is very high and sustained temps ... the additives likewise, but more likely to suffer from depletion in their protective properties. If your oil is breaking down, there is without doubt, something else going on in that engine.

 

I think D10 made a good point ... it's not so much oil breaking down, its contamination in the way of combustion particulates is the problem. Soot related wear is real and will cause wear long before the detergent and dispersants become saturated. Easiest way to deal with this is to change the lubricant.

 

Lube oil analysis will provide some insight into wear in the engine, but it really requires a lot of discipline to get a good trend (trend is the key) and very accurate records need to be kept and used to interpret the details... this is even more critical in a small engine... large diesel engines are much easier to do, which I suspect is were you have experience.

 

In terms of managing wear debris in a Jab engine, it really only takes a small amount of training to read the particulates in an oil filter ... this is a very simple and very acceptable way to read the tea leafs on an engines condition and future.

 

Cheers

 

Vev

 

 

[turboplanner]

Yes Vev, my oil analysis experience comes from diesels, where the sumps are also a lot bigger. At $30 I agree with you.

 

2.2 Lt for 80 hp does seem very small. I wonder if there was any testing with header tanks?

 

 

[old man emu]

When you quote a price for an oil analysis, that's just the price the lab charges. Don't forget to factor-in the cost of collecting the sample and getting it to the lab. Plus the down time waiting for results on which to base a decision. Also if you were thinking about doing an analysis, you were intending to do the change anyway.

 

3 litres of oil costs $30, plus $5 for a filter; downtime 1 hour. Why add the costs equal to another oil change?

 

The best guide to the engine's wear is to make sure you always CUT OPEN THE OIL FILTER AND INSPECT THE FILTER MESH.

 

Old Man Emu

 

 

[Vev]

Hi Turbs,

 

Of course there are no header tanks in Jab's but other engines do. One could do what is called a patch tests (look for wear debris), crackle test (check for water) and may be a fuel dilution test (looking for fuel and help indicate soot levels) which are cheap and quick to do. You would still need to buy some specialist gear and need a little bit of training to really know what you are looking at, albeit it's not very hard to learn.

 

However, I think there is plenty of process to ensure one is keeping an eye on the engine if we follows all of the required maintenance and running procedures to alert us to any potential problem... not wanting to tell you how to suck eggs of course, doing pull throughs each day, running an engine frequently at full operating temp, doing leak downs etc etc will go a long way to making sure all is good and one is ahead of the curve.

 

I'm still in the camp of changing lubricants early, I'm not suggesting this is a requirement but saying it's a good insurance policy... examining the filter debris content each time is a great way to manage wear and very easy to do.

 

However, to your point, big diesel engines, turbines, industrial gear boxes etc etc are a different kettle of fish and I wouldn't hesitate in plugging in a full oil condition monitoring programme... crazy if one didn't.

 

Cheers

 

vev

 

 

[jetjr]

OK so the cost benefit isnt likely to stack up based on extending oil servicing BUT as we are talking engines with just 1000+hr (2000 if your a believer) life perhaps theres benefit in monitoring stuff we cant see in the oil. Just take a sample at the change.

 

Ive been cutting filters open for a while and never have I seen more than a few chips in a new Jab engine, sometimes a tiny spot of coppery stuff.

 

How do workshops actually process the filter media to find everything. Lots of potential for debris to either get lost or left in the discarded filter body and its a messy job.

 

The Ryco filters need the media to be cut out and then old black oil drained or rinsed out - how do you do it?

 

 

[Vev]

Hi Jetjr,

 

This may help answer your question.

 

http://www.eaavideo.org/video.aspx?v=3735936001

 

Cheers

 

Vev

 

 

[Vev]

http://www.eaavideo.org/video.aspx?v=1674033150

 

Cheers

 

Vev

 

 

[jetjr]

Good links thanks

 

The method of washing media is near exactly what I do now. As I came to this idea myself I just figured there would be a better method.

 

The Jab filters seem to retain a fair bit of oil and ~ 50ml oil spreads a long way on the bench.

 

 

[turboplanner]

OK so the cost benefit isnt likely to stack up based on extending oil servicing BUT as we are talking engines with just 1000+hr (2000 if your a believer) life perhaps theres benefit in monitoring stuff we cant see in the oil. Just take a sample at the change.Ive been cutting filters open for a while and never have I seen more than a few chips in a new Jab engine, sometimes a tiny spot of coppery stuff.

How do workshops actually process the filter media to find everything. Lots of potential for debris to either get lost or left in the discarded filter body and its a messy job.

 

The Ryco filters need the media to be cut out and then old black oil drained or rinsed out - how do you do it?

Particles you can see are either swarf from manufacture, which is not ideal, or deterioration which is past where you'd like to know about it.

 

Oil analysis is at a microscopic level, with the results showing up early enough for you to do a pull down and replacement rather than rebuild a blow up.

 

With an engine with a reputation for lasting forever, even with lumps of metal the size of ten cent pieces in the system (Rolls Royce Merlin, Bedford 466), you wouldn't be too fussed with oil analysis, and with what Vev and I were talking about earlier - 2.2 litres of oil change, you might not want to increase each service cost.

 

On the other hand, with an engine which is prone to problems, and a $16,000.00 replacement cost, it can be a good investment to catch issues developing at the microscopic stage.

 

 

[Alan]

In addition to cutting the filter open as recommended, I have done "Ferrography" on my used oil (magnetically extracting the ferrous wear particles to a microscope slide and examining the wear particles under a microscope. I find "Filter Patch" can be blinded by carbon and dirt) and SOA at each oil change. I know this is a totally "over the top" approach, but I have easy access to oil analysis facilities. Nothing really abnormal ever found, but interestingly the amount of corrosion (barrels?) found in the oil, if only in minor amounts, reflects pretty much the usage and climate of FNQ. The motor always has its exhaust and intake covers put in place while still hot - just shows how pervasive water can be.

 

Alan

 

 

[bushpilot]

Talking to a LAME who supplies oil to an owners of 2 Jabs and a Rotax Foxbat and he recommends USA made Phillips XC Aviation 20W 50 oil. I dont know what the position of Jabiru factory is on this oil though.

 

It is apparently commonly used in a number of types of GA engines. Anyone else out there use it?

 

 

[turboplanner]

"I use"

 

"A mate uses"

 

"A LAME supplies"

 

Do you really want to base an already precarious engine investment on this level of advice.

 

I already know of several people who are no longer aircraft owners because they couldn't afford a second, or third engine.

 

Phillips engine oil may be great, but of the manufacturer's oil galleries have a problem, or the pressure points/clearances have their own characteristics, then the chemical structure of an oil may shorten life rather than extend it.

 

So before I jump ship, I'd like to see the actual engine life test statistics on at least 100 engines.

 

There's a 19th century proverb relating to two laconic farmers walking on the road to work early in the morning.

 

Day 1

 

Farmer 1: "Morning"

 

Farmer 2: "Morning"

 

Day 2

 

Farmer 1: "Morning"

 

Farmer 2: "Morning, what did you give that horse of yours that was sick"

 

Farmer 1: "karosene"

 

Farmer 2: "Morning"

 

Days 3 and 4 same as day 1

 

Day5

 

Farmer 1: "Morning"

 

Farmer2: "Morning, I gave my horse karosene and it died"

 

Farmer 1: "So did mine"

 

Farmer 2: "Morning"

 

 

[jetjr]

From the J230 pilot handbook, This is on the website, not too hard to find, written 2010.

 

I read that commercial grade 50 (as in 15W50) is the same hot spec as W100+ hence the dual recommendation.

 

As with anything , make sure if you own or work on Jabirus you have the latest manuals.

 

ALL the Jab engine manuals and POH now have the same statement in them regarding oil selection as below

 

The only confusion could be with conflicting information in old model handbooks which could have been written before multigrades were easily available.

 

2.4 ENGINE OIL

 

Jabiru Aircraft approves lubricating oils of any brand name conforming to specifications MIL-L-

 

6082 for straight mineral oil and MIL-L-22851 for ashless dispersant oil

 

AND

 

8.2 OIL

 

8.2.1 Engine Oil Specification:

 

Jabiru Aircraft approves lubricating oils of any brand name conforming to specifications MIL-L-

 

6082 for straight mineral oil and MIL-L-22851 for ashless dispersant oil.

 

Straight mineral oil must be used during the first 50 hours of operation for new and overhauled

 

engines, or until the oil consumption has stabilised. After the first 50 hours it is recommended

 

that ashless dispersant oil be used.

 

8.2.2 Engine Oil Viscosity Grade:

 

The following chart is intended to assist in choosing the correct grade of oil and must be

 

considered as a guide only. Multiviscosity grades can also be used as indicated

 

Average Ambient Temperature MineralGrades Ashless DispersantGrades

 

Above 35° C (95°F) SAE 60 SAE 60

 

15° C to 35°C(59° to 95°F) SAE 50 SAE 50

 

-17°C to 25°C(1° to 77°F) SAE 40 SAE 40

 

Equivalence of SAE and commonly used Commercial Grade designations:

 

SAE: 20 30 40 50 60

 

Commercial: 55 35 80 100 120

 

Even POH for J400 (solid lifter engine) from 2004 list this information

 

1.2.5.APPROVED OIL GRADES

 

Oils developed and branded for use in aircooled aircraft piston engines

 

(eg Aeroshell 100 plus)

 

In cold climates

 

Aero Oil W Multigrade 15W- 50

 

Or equivalent Lubricant Complying with, MIL-L-22851C, or

 

Lycoming Spec301F, or Teledyne Continental Spec MHF-24B

 

 

[facthunter]

I think you are all worrying too much over what is a simple low stressed engine. Some parts of it may overheat. STOP those parts getting too hot.

 

Filters will show that damage has happened. That is often a method of determining serviceability of an engine, ( very much so in Jet engines).

 

The filter stops particles doing further damage. Volkswagens didn't even have one.

 

If you leave your filter on too long it may block and lots of accumulated grunge may bypass it and ruin the motor.

 

Oils additives get used up with time. Viscosity stabilised oils ( multigrades) have polimers in them to "flatten' the viscosity index. They will lose some of their effectivenes over time but it is a lot longer than the intervals we are talking about.

 

The most important thing is to have the operating oil temp at around 85-90 degrees c. This will reduce the impurities (unburnt fuel and water) that remain in the oil'. Some dust may get there too. Short runs and dust present reduce the oil change period.

 

The oil itself doesn't get damaged much unless it is well and truly overheated. In any case it is bugger all amount so all you are worried about is the inconvenience, of changing it. It's a good opportunity to look around the motor for dark grey signs of fretting at the cylinder base mounts, oil leaks etc.

 

The aero oils with "plus" after them are developed for lycoming camshafts that are at the top of the motor and suffer from pitting from acids formed in the motor, and over time corrode if the motor is not used regularly. I would recomment these in any motor. Jab do, some I'm not suggesting anything radical. Nev

 

 

[nong]

The oil temp you run at is more important than ambient. You should try to get it to about 85c as a max in normal ops.If you get somewhere with a thicker oil in , and you get a frost you have to epend more time warming it up, as you may get cavitation due loss of sufficient oil flow on the suck side of the pump.. I spent 20 minutes on the ground at Corryong before I would do a mag check, last time.Some people have a bit of an aversion to multigrades and confuse them with detergent and other things. Most people have gone over to them.

The latest mineral oils have corrosion inhibiting additives, mainly for Lycoming camshafts, but do no harm in any motor that uses the standard oils.

 

Rotax use different oils, because of the drive clutch and gears. nev

It is not true that the additives in Aeroshell W100 Plus and W15W50 will not do harm in any motor that uses other oils such as 100 or W100. Shell warns that these additives can damage the big end bearing of radials such as Jacobs, Pratt, etc.