SI-912-016-R8

[Jim Meade]

From the SB:

 

"3.2) Operation with unleaded and low-lead fuel (less than 0.1 g/liter lead content)

■ CAUTION: When operating primarily on unleaded fuels or MOGAS, the maintenance intervals remain

unchanged in regard to the published maintenance schedule found in the currently valid

Maintenance Manual for the engine type.

In case of severe operating conditions (operation in cold/hot wheather areas, interference by and and/or salt), the time betwen maintenance intervals must generally be shorter, and in particular,

the frequency of oil changes must be increased regardless of the type of fuel mainly used

(MOGAS or AVGAS)."

 

Has anyone seen a definition by Rotax (or FD, for that matter) of cold/hot wheather (sic)?

 

Can some English major explain to me this phrase:

 

interference by and and/or salt)

[Jim Meade]

From 3.3

 

"The previous formulation of AeroShell Oil Sport Plus 4 can still be used until the expiration date."

 

As I read that word for literal word, it reads to me that at the end of the expiration date of the oil, I have to purge it from the engine. I can't use it. Nothing says, "don't add any after the expiration date". It says "can be used until...".

 

Sound to me like this goes on your maintenance schedule, just as you have time limitations on ELT batteries.

 

So....how do you log this? Do you add it to your oil change log entry? Change oil by expiration date MMDDYY?

 

If you say, "well, they didn't mean that. They mean don't pour it into your engine after the expiration date" please show me the source of your conclusion.

[Jim Meade]

From 6

 

"3. For turbocharged engines ensure an adequate running cool-down period to prevent deposits by coking of oil."

 

Many consider 5 minutes an appropriate cool-down period. Some take that to mean to taxi the airplane to the hangar and let it idle for 5 minutes.

 

Others start timing the cool-down from when the throttle is pulled way back, often on final. For many, that means that after landing, roll out and taxi back to the hangar, the cool down time may already be met. In other words, some say an arbitrary cool-down period in front of the hangar is neither necessary nor indicated, as the cool-down starts with significant throttle reduction and the consequent reduction of engine operating temperature.

[Jim Meade]

Note this SB is rather equivocal on what oil to use. It seems to say that Shell Aero Sport Plus 4 is the one and only oil, but it spends a lot of time telling a different story. A careful reading of 3.1 implies a number of oils are acceptable. 3.2 is specifically aimed at engines that run AVGAS or leaded gas.

 

6. talks about when not to use a petroleum based oil and when to use a full synthetic oil, but doesn't list any full synthetic oil.

 

Previous documents included a number of different oils, including full synthetic, but this poorly written document does a poor job of giving specific guidance for some operations, for example, the airplane that consistently operates at high temperatures on mogas should use a full-synthetic, but none is named.

[Jim Meade]

It is illustrative to read the Shell web site:

 

https://www.shell.com/global/products-services/solutions-for-businesses/aviation/aeroshell/products/piston-engine-oils/sports-plus4.html

 

Here is one extract that would lead one to investigate the other specifications to see which oils fit under there. JASO MA does talk about full synthetic, for example.

 

Meets or Exceeds Highest International Specifications

 

API SL

JASO MA

VW 502 00

Fully Approved – All ROTAX® 912 &914 Series engines, Rotax Service Instruction SI-912-016/SI-914-019;

Selection of suitable operating fluids for ROTAX® engine type 912 & 914 (Series).

 

AeroShell Oil Sport Plus 4 is the world’s first truly specific aviation engine oil developed for light sport and ultralight aircraft engines. This is an oil which is available throughout the world, backed by the proven history and dependability of the AeroShell family, and preferred by the majority of General Aviation pilots and engineers alike.

[Anticept]

Aeroshell is only approved because they paid rotax a lot of money to be tested and approved.

[Ian]

Aeroshell is only approved because they paid rotax a lot of money to be tested and approved.

 

But that's irrelevant - the fact is it HAS been tested and it IS approved - so therefore I use it!

[Anticept]

But that's irrelevant - the fact is it HAS been tested and it IS approved - so therefore I use it!

Which doesn't mean anything, because the other oils listed in the sb are also tested. Aeroshell just wanted extra special treatment, and it's working since everyone sees that "approved" line and go nuts over it.

[Ian]

It's not a question of "going nuts over it" - for me it's purely pragmatic, my aircraft flies about 100 hours a year so in the scheme of things the cost of the oil is neither here nor there. That being the case then why would I choose anything else?

Now, were I running a flying school with half a dozen Rotax powered aircraft flying a few thousand hours a year then the decision might be different .....

[Anticept]

I've only pointed out that "approved" on that service bulletin doesn't mean anything . I don't mean to put you on the defensive

[Ian]

Cory, not at all - I was just a tad surprised how a simple announcement from Shell appeared to have turned into a major debate!

But perhaps I shouldn't ever be surprised at some of the things on here - LOL !!

[FredG]

Jim, I'm not sure that the link you provided to the Aeroshell Sport Plus4 site is for the new oil.  If you look at this news release fro Shell,

 

https://www.shell.com/global/products-services/solutions-for-businesses/aviation/news-and-library/press-releases/2015/press-release03302015.html 

 

you see that they are announcing the new oil.  Shell is not especially clear about the differences between the new oil and the previous version of Sport Plus4.  

 

Your question about other approved oils is a good one.  They do not list any approved synthetic oils in the SB (although they did previously allow selected synthetic oils) yet they recommend use of full synthetic oil later in the SB when discussing high oil temperatures.  Pretty unclear.  

[FastEddieB]

On any forum involving internal combustion engines, one can find lengthy "oil" threads.

 

Benson's 5th Law*: "Oil is Oil".

 

A joke, but with a kernel of truth. With all the claims of Mobil1 and Royal Purple and the flavor of the day, actual reports of engine issues due to oil selection are extremely rare. People have driven a million miles or more using the cheapest store brand oil. Anecdotes pro and con for any specific brand/formulation make for pretty weak evidence.

 

As cool as our ROTAX engines are, they are not really that exotic. Very similar to any number of motorcycle engines, some actually also made by ROTAX.

 

Anyway, I've settled on the Aeroshell stuff, after trying Valvoline and Pennzoil stuff back before it was available. Only thing I noticed was that with the Valvoline I seemed to be adding a little oil every few flights, and some claimed it was due to "foaming". I have no idea if that's true, but when I switched to the Pennzoil my consumption seemed to go down.

 

Just my thoughts as a layman who's been around engines and oil debates for 50 years or so. Take them for what they are worth.

 

 

*Since my "Benson's Laws" are basically jokes anyway, I sometimes lose track of the numbering!

[FlyingMonkey]

I would personally call that the "Achilles Heel" of the carbureted ROTAX - really tiny pieces of crud finding their way to the float bowls can block jets and cause power interruption or failure.

 

Seems like fine screen filters right at the carb might help, like BMW airhead owners have installed for years after facing similar problems.

 

Anyway, it's been my first guess when a ROTAX owner has issues, and is most often correct.

 

Wouldn't a mesh screen just move the problem farther up in the fuel system?  If the crud accumulates at the screen eventually it will block flow there as well, and the carb will run dry.

 

If the idea is  "Well, you could clean the screens..." then the natural response is "you could drop the float bowls and clean them out, too!"  

[FastEddieB]

The filters used on many BMW's were transparent, so you could see the crud accumulate and catch it before it had any chance of stopping the flow of fuel.

 

 

I installed one of these after the fuel pump:

 

 

But a good point, nonetheless.

[FlyingMonkey]

Olarry.  Rotax would not recommend a full synthetic if using leaded gas. 

 

The key point is the EXCLUSIVE use of unleaded fuel, 91E10 for example or in Europe 91UL allows the use of full synthetic.  Once at that point, the full synthetic Mobil 1 Motorcycle Racing 4T is recommended, at least by Rotax West.  I assume you can find the same recommendation in Rotax literature somewhere. 

 

The use of unleaded gas lets you wait twice as long between oil changes.  Mobil 1 can stretch that even further, but I still change each 50 hours.  Mobil 1 has a better high temperature degradation, shear viscosity, optimal for both gear box and engine, and low-temp flow for cold starts.  It's made for racing engines and costs about the same as the Aeroshell but is far better.

 

Yes, a full synthetic oil is good to use if you EXCLUSIVELY use unleaded fuel.  But most of us can't guarantee that, or at least want the option to use 100LL if we have to.  

 

For example, when I fly to Page in October, that's a 1400nm trip, and I expect on my fuel stops there will no mogas available at the airfields.  So having the ability to use 100LL at those locations is a firm requirement of the trip.  If you never go more than 400nm from your home field, or one that has mogas available, then you can get away with a full synthetic oil.  Most need the flexibility to fuel with what's available.

 

One question.  This is honest, and not meant to be snarky or accusatory:  During the trip where you ran the airplane fuel down to just the header tank, was one of the reasons that you didn't stop en route for fuel because you were using a full syn oil and you could not fuel with 100LL, and no mogas was available at the fields in your route?

[FlyingMonkey]

The filters used on many BMW's were transparent, so you could see the crud accumulate and catch it before it had any chance of stopping the flow of fuel.

 

 

 

I do agree something more visible would be better.  Otherwise the safest practice would probably be to drop the bowls at every oil change.  Though I think SLSA owners would need an LSRM or A&P to supervise that.

[FastEddieB]

The LSA dealer at North Little Rock, AR had high octane MOGAS when I made the same trip, so I planned that as a stop.

 

But, yes, there's no practical way to make a trip like that without using a substantial amount of AVGAS.

 

Might check Airnav right before the trip to see if there are others enroute. Just make sure they have 91+, not all do.

[FastEddieB]

Otherwise the safest practice would probably be to drop the bowls at every oil change.

I might even do that monthly, if the bowls were accessible enough. Mine are a bit of a PITA, involving cowling and drip tray removal, with some difficulty getting them back in place.

[FastEddieB]

As an aside, it's a gorgeous day here in the GA mountains.

 

Anyone want to fly?

[WmInce]

. . . "there's no practical way to make a trip like that without using a substantial amount of AVGAS.

 

Might check Airnav right before the trip to see if there are others enroute. Just make sure they have 91+, not all do." . . .

 

Additionally, after checking Airnav, it is a good idea to call the FBO ahead and verify the online information.  Airnav is a good resource, but I have found some of the information and fuel prices to be dated.

Always good to call in advance before arriving.

[FlyingMonkey]

As an aside, it's a gorgeous day here in the GA mountains.

 

Anyone want to fly?

 

Soon, but not today.  My plane is reassembled, but I have to make some test flights first before flying "for realz".  I'm waiting for a near perfect day to do my test flights, since it's been six weeks since I've flown.   I'm at work today (can't you tell!) and by the time I get out this afternoon the winds are supposed to kick up to ~14 knots.

[Roger Lee]

"Check the Aero Shell pages from the UK.  The new formula changed the wear additive package (increased the levels of anti-wear materials) and the most significant is a change of the base oil used.  This is now a custom formula for Rotax and not anything like the motorcycle blend that they started with.  It took more than 4 years of testing in Rotax engines.  I think it was 8 blends they tested long term in flight school engines back at the factory that all ran up to TBO.  They then selected the best one of the batch."
 

 

http://www.transair.co.uk/sp+AeroShell-Sport-PLUS-4-Oil-Aeroshell-Sport-Plus-4-Oil-12x-1-Ltr-ROTAX-912-914-Series+2675CASE

 

 

 

"Thomas Uhr, General Manager BRP-Powertrain said, “The collaboration of BRP-Rotax with Shell goes back to 2004. Our decision to work with the AeroShell team on the development of the new formulation for AeroShell Oil Sport Plus 4 was based on the benefits the new formulation would provide to our customers. This joint development is supported by 40 years of Rotax aircraft engines, 25 years and more than 50.000 engines produced within the Rotax 912/914 engines with more than 45 million hours of flight."

[FredG]

Where does one find AeroShell pages from the UK?  I was looking on the main Shell webpage.  How can the new oil be "not anything like" the prior oil when it still meets the same JASO requirements?

[Roger Lee]

Meets requirements is a minimum standard and shows nothing about higher grades above that designation. It can exceed that designation and will only say it meets that requirement.

Aero Shell will not produce a formulation list of exact chemicals as it is proprietary to them.