Abstract: A valve comprises rolling diaphragm (7) supported at its outer periphery by an annular support member (8) within which the diaphragm rolls in response to inlet pressure so as to uncover an outlet opening (20) in the support member, thereby to allow the escape of said pressure. Preferably, the diaphragm (7) is annular and is supported at its inner periphery by a guide member (9) that engages on abutment (19) when the outlet opening (20) is closed by the diaphragm, and that guides the diaphragm as it rolls back and opens the outlet opening (20). Preferably, the outlet opening (20) is of reduced width towards that part which is first uncovered by the diaphragm in operation. The valve may include a two part housing (1, 4) with the support member (8) located between the two parts and with the outer periphery of the diaphragm (7) gripped between one part of the housing (4) and the support member (8).

Abstract: An engine sump 4 has an oil suction passage 7 formed in its side wall to communicate with the sump well 6 at its lower end and to open upwards at its upper end to communicate with a passage in a crankcase 3. Preferably, the passage 7 opens into an upwardly opening gallery 13 in the top of the sump wall along part of its length. Two such oil suction pipes 7, 8 may be provided at opposite locations relative to a central point so that the sump 4 can be rotated 180 degrees about this point from one fitting position to another. A filter element 11 may be provided in the oil suction passage 7 and held therein by the crankcase 3.