Mike Busch Maintenance Forums

[Bill Greenwood]

I went to two maintenance forums by Mike Busch, and it seems worthwhile.

But I have some questions in one area; that of the forum on oil types.
Mike says the main item of wear in an aviation piston engine is from corrosion, as when the engine is not being flown and is sitting.
He than picks his favorite oil type on this basis.
Now the conditions where a plane is based are a factor, for instance in the humid salty climate of the Gulf coast it may be a big factor.

But Mike really did not mention friction wear, especially on first start up on an engine which has not run in awhile and which is devoid of oil in the upper end.
I think this is the source of much wear, not just corrosion, especially where I live in Colorado that is very dry and part of the year is cold.
He likes single weight oil, like Aeroshell w100, and didn't advocate preheating the oil, before start up. I think in many parts of the country that will lead to wear on initial running.

I use a multigrade and usually preheat, or try to. Even in May or Sept we may have night temps down around 40 degrees and 100 weight oil doesn't pump very well through small engine passages then.

He also advocates changing oil every 4 months on a time basis, not just hours run. I don't know anyone who does that, don't know if it is good or overkill.

He likes oil analysis and checking the filter. It has been my experience that if the filter is clean, the analysis is likely to be also.

This is all sort of informed guess work or personal experience. No one takes 100 of the same engines and runs half of them on multigrade and the other half on w100, in the same conditions, to see the actual results, like you'd need to to the really have factual reports.