Is DLC the Cure for The Lycoming Achilles Heel?

[Magman]

“Use of other than mineral oil will void all warranties”.

This was the wording of a well know Engine rebuilder 50 YEARS AGO.

Times have changed and oil has to some extent.

Old School was thick oil to stick to components.

New is the “ wetting agent” that enables oil to stick and be there

at Start.

 

[nitpick]

Your statements about oils disagree with everything I have every read. Multi-weight oils are thinner at lower temps, especially compared to single weight oils; they are designed this way to facilitate startup of the engine.

Tim

That's actually exactly what I said. A multi weight, say a 15W-50 has a base viscosity of 15 at 0C and a viscosity of 50 at 100C. Above 100C a multi weight 15W-50 does not lose viscosity as quickly as a straight 50 weight

 

[Dan Thomas]

At normal engine temps at shutdown, that oil--any oil--is not going to be thick enough for much of it to stick to anything. It's going to run off. Modern oils have additives to leave a thin film for corrosion protection and lubrication during start.

Single-weight oils are thick so that they will still lubricate as they thin out with heat, but the oil takes a lot longer to reach the moving stuff during startup when the weather is cold. Stick a quart each of W100, W80 and 15W50 in your freezer over night, then pour a little out of each one to see what a few degrees below zero does to the single-weight oils. W100 and W80 are SAE 50 and SAE 40 respectively. 15W50 is an SAE 15 oil when it's cold and acts like an SAE 50 oil when it's hot; the best of both worlds. It has magic molecules of some sort that clump together to thicken the oil when it gets hot, or, more accurately, they clump together to reduce the rate of thinning in heat.

This is for an automotive multigrade, but you get the idea:

 

[Tarheelpilot]

DownLoaded Content??

doubt it would help.