The engine manual says to the change the oil after the first one hour of run time. I have about 0.8 hours of ground running, so decided to change the oil. With the oil warm, removed the safety wire from the oil sump fittings, attached a drain hose to the drain valve, and drained the oil. Very simple and clean using the drain valve.
Removed the sump strainer and inspected it. There were some traces of assembly sealant in the strainer, and some minor non-ferrous traces of metal. Nothing unexpected for a newly assembled engine. Since I am not using the extra 1/4 NPT fitting on the Sonex sump plate, I tried to install the standard steel plate. That plate had interference with the forward casting on the case. The case could be ground slightly to make the steel plate fit and eliminate a potential 1/4 NPT leak point, but I didn't want to risk contamination of the engine. I reinstalled the Sonex aluminum plate.
Over extended periods, I've seen a small accumulation of oil on the sump plate nuts. I suspect this is weeping along the stud threads since the studs penetrate into the oil sump. Perhaps this is why the original VW engine used the acorn nuts along with the copper washers. If I continue to see weeping, I might try the acorn nuts and see if that seals it.
Installed safety wires on the sump fittings and refilled the engine with 2.75 qts of 20W50 Valvoline VR1 racing oil.
