What engine oil? SAUER engine

[microlightgary]

Hi all,
I have a small percentage share in G-AVKI (had my first 3 flights today!) and just wondered what oil people generally use in their engines? I've used Shell multigrade aero engine oil in a Jabiru engined machine (not a Nipper), but have no experience with the VW derived engines at all.
G-AVKI has the SAUER engine, can any VW drivers tell me what oil is generally recommended please?

Many Thanks

Gary Taylor

[G-ARBG]

Gary,

I use Castrol GTX 10W-40 in my VW powered Nippers which is also the oil recomended for my motor glider (Limbach 1700 VW).

David G-ARBG

[microlightgary]

Thanks David, bought a bottle today, BUT any idea why automotive oil is 'ok' in the VW derived engines?
I would really have expected the Aero Shell multigrade (or similar) to be used. The usual argument against automotive oils is that when used in car engines, you don't often sit flat out for hours on end and indeed, the oil isn't designed with this in mind. Aero oil is though, hence I'm inclined to go with an aero oil as in the Jabiru, which is broadly speaking similar to the vee dubs...
Anyone got any thoughts or expert knowledge on this subject?

[Tipsy Flyer]

Hi Gary,
If i may jump in here, the oil gallaries in the vw crankcase are small in comparison to an aero engine and aero oils are reasonable thick oils which adds up to flow problems. The problem is not so much the running at high rpm but keeping the oil temps in the green. VW's are air and oil cooled.
Hope this helps.
Regards
Glen

[G-NIPR]

I am running a VW 'Ardem' type with 1834cc and asked this very question when I first bought my Nipper.
A conversation with Barry Smith ( He who knows!) revealed that many oils are suitable for the humble aero VW, but he uses just regular Castrol GTX or similar. He said to avoid synthetic oils with these motors.
The important thing is to change regularly, and the advantage of using GTX is that it is cheap enough to change very regularly.
I also got further information from John Maher of JMR racing, he rebuilt my engine, and his firm choice of oil is Millers multigrade. Not cheap!
I am currently using AeroShell w80 because I was given a couple of boxes of it.
To sum up the rules I live by are to avoid synthetics and use good quality mineral oils, and change every 25 hours.
So far all is going well,

Paul.
G-NIPR.

[G-ARBG]

Gary,

Further to my earlier, quote from the Nipper MKIII owners handbook 1967 -
" Oil - viscosity W80, Type Aeroshell, Capacity (3 ltrs)" Ardem Maintenance and Overhaul Manual also specifies W80 (although it has amended capacity to 4pints -2.33 ltrs)
I wonder if aviation approved oil was an ARB requirement in the early days?

Limbach Engine Manual (VW derived engines) on the other hand state - " Do not use non-detergent oil or detergent aviation oil! Use oil only, which is standard oil for car engines and marked 'SE' according to the API - system"

Castrol GTX 10W-40 complies with their Engine Manual lubrication chart for lower temperate climate which includes SAE 10W-40.

I propose to carry on using Castrol but would be interested in an expert opinion on the above.

David G-ARBG

[G-BLMW]

Hi All

My view is that it is after all a car engine and was designed as such (as my inspector once said ithe engine doesn't know its in an aeroplane!) therfore I use GTX with regular oil changes.

Cheers

Stuart

[microlightgary]

Stuart,
the engine may not know it's in an aircraft, but if it thinks it's still fitted to a car, it must wonder why the hell it's being thrashed within an inch of its life every time its owner goes driving!
Would love a definitive answer, but will continue to use GTX for now...

[G-BLMW]

Blimey, how many of them RPM's do you use? but a valid point, although a 1970 stock Beetle engine will develope 54HP @ 4400 RPM from 1584cc displacement so I feel 2950RPM is not really asking too much. Regular oil changes are the best deal when using GTX and it is relatively cheap. You might find the thread 'What oil do you use' posted by Neil Spooner on Wed May 6 2009 and the article contained 'Lubrication of Classic VW AIr Cooled Engines' very interesting. I had forgotten all about it.

Cheers

Stuart

[microlightgary]

So the engine is effectively de-rated then? Interesting stuff; you'll have to excuse my ignorance, I've been flying for just 6 1/2 years, almost exclusively in front of Rotax engines (various 2 and 4 strokes) or behind a Jabiru, so the VW derivations are a whole new learning curve for me!

Gary T

[jantar]

Just to throw in my small amount of info. Ardem/rollason said use Aeroshell 80. Well its not available in South Africa! A bit more digging revealed that its SAE viscosity is 40 !!! so dont be misled by the 80 ! W80 should not be used to run in new engines. I have purchased car SAE 40. Neill Spooner has a very informative article somewhere in this forum. Regards Jantar