WW2 era US military aircraft piston engine oils

[walterjay]

Oh and these oils never ever use zinc additives, nor do any aviation motor oils.

I find that very interesting.

 

[Kuato]

I once talked to a WWII aviation mechanic and he was stationed in Alaska during WWII, and said they use to reduce the viscosity of the oil in the aircraft engines by adding gasoline to it.

It is also worth noting that many of those engines had a system that allowed oil to be added to the engine in flight to make up for loss. That would have made it possible to thin the oil that was in the engine more for starting and then add thicker oil during flight, but I do not know if that was done.

There is a C-54 flying museum that I got to tour a few years back; the tank used to add oil in flight was 60 GALLONS!!

 

[GoToGuy_Ron]

When speaking of Geared Radial Aircraft Engines. You are identifying those engines that have gear reduction assembly. That allows operating the engine at a higher RPM then through a reduction gear assemby propellor RPM is kept below supersonic. The Pratt & Whitney R-1340 Wasp, was one of these. A planetary gear reduction ratio of "3.2 " The other is prop' is directly attached to engine crankshaft. Therefore Engine RPM is propellor RPM. Large Radial Forever!

 

[GoToGuy_Ron]

The process for any POL products (petroleum, oils, lubricants) for use in Aviation is set at much "higher bar" The quality, standards, definition of what is compatible or, "equal to or better" is black and white. That is one thing I personally like, I have, AN standards, Mil Spec, NAS ( National Aerospace Standards) , and SAE where applicable. Yeah, more binders and paperwork, but i can allways find an answer, well 99% of the time. I had to call Rolls & Royce about an armored car one time. Oh well good luck.