Cowboy, I never use Aeroshell Plus in any of my aircraft. It has an additive that was put in to overcome a Lycoming cam problem on the O-320 H engine. Here's an article from Skyranch;
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Do straight mineral oils have the same low temperature flow as straight ashless oils?
No. Due to the additive technology in ashless dispersant lubricants like AEROSHELL W Oils, the flow characteristics of each grade are roughly equivalent to the next higher straight mineral oil grade. For example, AEROSHELL Oil W 100 will flow at low temperatures about the same as AEROSHELL 80.
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Are single and multi-weight oils compatible
The compatibility question covers two issues: mixing one type of oil with another; and the effects on the engine of changing from one type to the other.
If you typically run on multi-grade, and you find yourself in a place where only single grades are available, you can safely add the single grade to your engine. They are completely compatible.
If you run on a single grade during the summer, but want to switch over to 15W-50 for the winter, you can safely replace the straight weight with the multi-grade at your regular drain interval.
The idea that you have to stick with the type of oil you started with comes from the days unusual chemistry was done and was incompatible.
All approved MIL-L-22851/SAE J-1899 and MIL-L-6082/SAE J-1966 oils are compatible. For example, if you have a high-time engine run on ashless dispersant oils and need to replace a cylinder, you can switch to a mineral oil for 50 hours or so to break in the new cylinder. The only time I recommend against switching is in a high-time engine run exclusively on straight mineral oil. Here a switch to ashless dispersant oil can loosen deposits left behind by the mineral oil.
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What is Phillips Type M oil
Type M is Phillips multi-viscosity mineral oil
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What is meant by the term detergent and non-detergent
Detergent and non-detergent are not used anymore.
"Detergent" is replaced by "Ashless"
"Non-detergent" is replaced by "mineral"
Mineral means a non-additive version of regular Ashless oil used during new engine break-in
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What is the difference between 50 weight and 100 oil
Aircraft engine oils (except multi-grade oils) are duel rated:
SAE 40 is the same as 80
50 is the same as 100
60 is the same as 120
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What is Aeroshell Plus Oil
Aeroshell Plus is Aeroshell oil with the Lycoming LW-16702 oil additive. Lycoming '76 series engines (engines such as the O-320H2AD) require LW-16702 per an airworthiness directive to prevent camshaft lobe galling. By offering the additive as part of the oil it simplifies AD compliance and assures that the oil receives the additive.
LW-16702 is classified as an "EP" (extreme pressure) that is a surface reactant that chemically combines with Fe forming phosphides or phosphates. This protective film is a few molecules deep, that is swept away by shearing friction, and renewed thereafter. Thus LW-16702 is, in a sense, actually corroding the metal surfaces, however slowly.
Because the reacted metal surface has low shear strength, the sliding friction is markedly reduced, and the tendency to severe adhesion is reduced or even eliminated.
The combination of a higher surface energy of the freshly worn surfaces, local high temperatures, possible catalytic effects and any other activation processes makes the action of LW-16702 specific, taking place preferentially at the wear points (surface irregularities) where it is most needed.