- Tue Jul 01, 2014 10:19 pm
#37122
My Enfields get a good [Morris's] 20/50 in their engines, gearboxes and primary cases and give no trouble for it. The racers get more expensive [Valvoline] 20/50 in their engines and primary cases, while their 5 speed gearboxes get a so-called 80 grade gearbox oil, although it is actually quite thin, like hydraulic oil. All this works fine for us and a point to consider is the possibility of cross flowing of small amounts of oil between engine and primary, even with a seal between the engine and primary case. Wet sumping, especially when on the prop stand for any length of time, can put a fair bit of engine oil into a primary case, so you might as well have the same oil in there to start with and then you only have to let the excess out via the level plug if such an event should take place. Just my personal preference and it saves complicating things. Regards, Paul.