Alternative to real aviation oils?

Radioflyer · #1 03-23-2018, 05:08 AM

I know that the standard approved aviation oils are mineral oil based and require the ash-less dispersant qualities. I know that the zinc in typical automobile oils does harm to our air cooled Lycomings and Continentals. Out of curiosity, with so many oil formulations out there, does anyone know of an automobile, truck, marine motor oil that does not have zinc and is ashless dispersent?
Please, no flames, it's just a curiosity...I'm devoted to Philips+Camguard for my O-320.

Red Mtn flyer · #2 03-23-2018, 06:25 AM

Zinc additives [ZDDP in mineral oils, ZDTP in synthetics, or combination] are actually lower in modern oils for automotive engines, and have been trending that way for many years. [There are several reasons for that, tied to 'modern' engine design choices.] However, because - among other things - our aircraft engines use flat tappet bodies in the cam/ lifter/ valve train, we need the zinc additives for lubrication.
The highest pressure point in our engines [Lyc/ Conti/ Franklin] is between the cam lobe and the 'lifter' [tappet], even with the newer roller tappets. The lubricant film here is exceeding thin: hence one of the major needs for the 'sacrificial' lubricant characteristics of the zinc additives.
To your original question: in the Light Sport world, where use of adapted engines [think Rotax, Zenoah and others], there is a school of thought that prefers certain automotive - type oils... which i'm not going to advertise here. This shouldn't be surprising, given the different design choices made by those engine manufacturers.
Meanwhile, I also prefer your 'mix' - adding CamGuard - fwiw - in my IO-320.

rv7charlie · #3 03-23-2018, 08:01 AM

Here you go:
http://www.vansairforce.com/communit...rchid=34610993

rv6ejguy · #4 03-23-2018, 09:17 AM

There was a discussion on Mobil 1 oil here a while back: http://www.vansairforce.com/communit...d.php?t=139177

Since this time, I know a second guy flying a Lycoming who has several hundred hours and many years using Mobil 1 with no issues yet.

Robin8er · #5 03-23-2018, 11:42 AM

I've wondered if Harley Davidson oil would work in an "emergency". But I don't know where you would find harley oil that you also wouldn't find an airport that had oil available.

F1Boss · #6 03-23-2018, 01:17 PM

Yep - had this conversation with Jim, and he had already run thru the question with a Phillips engineer - off the record of course. The engineer's recommendation was to add 25% Phillips auto oil (20W-50 full synth) to 75% Phillips X-CY, basically making up your own semi-synthetic ashless oil with the best ingredients of both worlds.

I have a fair amount of Brand A (full synth ashless) to use instead of the Phillips auto, so I am using that formula with good results.

So, I would think that in a pinch - with no av oil around, the synth auto oil (likely ashless) will do.

Jim always used synth ATF in his hyd systems too.