Aeroshell Oil in Continental Engines

[doug8082a]

Hadn't heard about the additive/magnesium issue. Thought most of the corrosion in the pains was caused by water laying there.

Same here. The issue of water precipitating out of the oil during periods of inactivity and corroding the oil pan has been a known problem for many, many years. It's not an issue specific to the Aeroshell additive. I have no way of knowing if the additive makes the problem worse, but it's not the source of the problem.

[c170b53]

I thought the recommendation not to use the shell oil was due to cylinder problems it caused.

[Tom Downey]

Please read the Oil Talk for Dummies at :

http://eci2fly.com/ECi_PDF/BI05-2006.pd ... rks&page=3

and please pay attention to the EP Lubricants, the last statements says it all.. (Polishing is a form of wear)

[tshort]

Interesting...
I have used Aeroshell 15-50 in my Lyco IO-360 in the skyhawk for 3+ years with good results.
The 170 came with the same oil, and that is what I have been using so far.
These guys seem to say that any semisynthetic is bad. However, one engine builder that I talked to at OSH said he wouldn't put the Phillips "in a damn lawnmower". Makes me wonder about some agreements that these guys might have with different oil manufacturers.

My "old timer" buddy Stu always says that these engines are 1940's technology and don't need fancy oil to run - hell, 60 years ago they ran fine on simple oils.

I guess I should have stocked up on the Phillips XC 20-50 for 25$/case at OSH

Thomas

[Steve Pierce]

My Dad and I usually ran Aeroshell W100 in summer and 15w50 in winter. The belly always got oily from the 15w50. He came down to TX from TN on a fresh oil change of 15w50. The belly was oily and had been clean. Changed oil and added W100 and flew home (5 hrs.) no oily belly. He is a mechanical engineer and never satisfied without a scientific explanation. He talked to Aeroshell and Phillips at S&F. Aeroshell semi-synthetic (15w50) has some properties that are thinner and leak or blow out easier than mineral based oils. Phillips is all mineral based and doesn't have those properties. Since switching to Phillips 20w50 no oily belly or leaks, it is cheaper, and I can use it year round.

[Bruce Fenstermacher]

I thought the recommendation not to use the shell oil was due to cylinder problems it caused.

It very well could have been. Remember I said what I thought I remembered might be a stretch.

I do remember that the Lycoming additive was designed to help an issue Lycomings had and Continentals don't and that the additive created issues over time for the Continental engines.

[spiro]

why they didn't like the additive. How was it bad for the engine?

iirc the problem with AeroShell Plus or 15-50 is the additive package tends to leach out the copper in the bearings. The oil analysis folks see a very noticable difference.

or maybe I'm thinking of something else.

my preference is to run straight weight oils in air-cooled engines. For my 170 that's AeroShell W80 in the summer and W65 in the winter.

- paul

[GAHorn]

The "Oil for Dummies" article is interesting and largely correct, but has some errors (for example, the claim that "W" designates a winter-use oil. In automotive oils that was once true...but no longer. In aviation oils it never was true. AeroShell 100W merely indicates a mineral-based oil With additives.)

The only notation I've ever read regarding the use of AeroShell "plus" oils is their phosphate additives which can show increased leaching of copper/yellow metals in engines that are inactive. This "phosphate" additives would include tricresyl phosphate...the major component of the Lycoming-required additive (and which is included in AeroShell 15W50 oil and "plus" oil.)

Choice of engine oil is another topic subject to heated differences of opinions. The main thing to keep in mind (in my opinion, of course) is that these are low-rpm, lowly-stressed engines that do not require sophisticated lubrication. Plain, non-dispersant (popularly referred to as "mineral") oils will take your engine all the way to TBO if frequently changed, operated, and filtered. Additive oil is icing on the cake.
Straight-weight oils are probably best in all-around service, as they tend to remain on parts longer during storage/disuse. (Less tendency to drain off parts and therefore protect longer against rust.) Multi-wt oils are probably best for engines that are used in cold climates and are not properly pre-heated. (But remember, a 15W50 or 20-50 oil is really a light-weight oil with additives that make it behave like the heavier designation at 100-degrees C., but once depleted, have only light-weight oil characteristics.)
But straight-weight oils are specified for our engines if the higher 240-degree operating oil temp limitation is to be observed. (Of course, my personal favorites are AeroShell 100W, SAE-50 in summer, and 80W, SAE-40 in winter, because they are most widely available, even at small airports, and usually less expensive due to their widespread use. They also have a long history of reliable use.