Oil brand and type

[Sundaypilot]

Hello I have a 1976 anniversary edition 4108, I rebuilt the engine and installed a cast iron sleeve. And an early 80’s 6211 that I engine swapped an opposed 19.5 hp Briggs into. Both run great and use very little oil. I was just wondering what you guys use for oil. As for me I use Phillips Victory 20-50 aviation oil. It’s my reasoning that they both (piston planes and mowers) are air cooled and run near redline most of the time. Anyone have any other options?

 

[Auto Doc's]

Sounds like you are using better oil than what the OEM recommended back when new. Most all OE engines have been prescribed to use SAE 30 or 10W-30 for years.

I tend to prefer Royal Purple because I run it is all of my old Harley's. It's great oil. Other that I use Castrol GTX.

Down here in South TX, 20W 50 works perfect in any air-cooled engine.