FA24 Sump Design:
The FA24’s engine design uses a 2-piece sump design. The lower piece is made from stamped steel, has no baffle, and holds less than half of the engine’s oil capacity.
The upper piece is made from cast aluminum, has oil drain-back accommodations for the rear of each head, a flat plate baffle near the crankshaft to reduce aeration and reduce crankshaft induced turbulence that can impact PCV, and holds most of the oil. The drain backs are baffled, unlike previous Subaru engines that have head drains that were open to the sump. This is a good step forward in improving oil control; oil surge back-feeding into the heads during cornering.