Generally, an overflow conduit is described in apparatuses, systems, and methods to protect a crankcase oil sump from overfill. The overflow conduit is to be connected to a crankcase oil sump of an engine, and is configured to passively receive oil from the crankcase oil sump to avoid an overfill condition from occurring in the crankcase oil sump. The overflow conduit is configured to deliver excess oil received to a sub-base tank located relatively below the crankcase oil sump, or in particular at or below an oil level in the crankcase oil sump.