The invention relates to a crankcase oil catcher with a movable guide. The crankcase assembly for an engine comprising: a crankcase comprising a crank sump; the crank sump comprising primary and secondary sump volumes; one or more crankcase oil catchers, the crankcase oil catchers comprising surfaces to catch dispersed oil in the crankcase and direct the oil away from a crankcase casing wall and towards the crank sump, wherein the crankcase oil catchers are provided above a crankshaft and below a piston of the engine; and one or more guides to collect oil and guide the oil to the primary sump volume. At least a portion of the guide is movable between: a first configuration in which the guide collects oil captured by the one or more crankcase oil catchers that would otherwise have flowed into the secondary sump volume and guides the oil to the primary sump volume; and a second configuration in which the guide permits oil captured by the crankcase oil catchers above the secondary sump volume to flow into the secondary sump volume.