Abstract: An oil cleaning assembly for an engine comprising a centrifugal separator and a filter which are both releasably connected at one end to a mounting means and which both have an oil inlet and an oil outlet at said end, the centrifugal separator being arranged to extend substantially vertically upwards from the mounting means and the mounting means providing a common oil supply passage for the separator and filter, a drain passage for draining oil from the separator to the engine sump and a discharge passage from the filter for supplying oil to the engine lubrication system.

Abstract: An oil cleaning assembly for an internal combustion engine comprising a centrifugal separator rotor and an oil filter element, wherein the filter element is located in an annular housing which extends around the rotor.

Abstract: The reinforcement of the crown of a piston of aluminum or aluminum alloy for an internal combustion engine comprises the preparation of a reinforcement member (10, 13) which is provided with apertures (11, 14), or reentrants. The reinforcement member is placed in a crown-forming part (18) of a piston die in a squeeze casting apparatus and the piston is squeeze cast. The molten metal penetrates the apertures, or enters the reentrants, and these are so shaped that when the molten metal has solidified, keys are formed which connect securely the reinforcement member to the aluminum or aluminum alloy. Further reinforcement members can then be readily brazed or welded to the first reinforcement member.

Abstract: A piston for an internal combustion engine is provided with a crown portion heat insulated from the remainder of the piston over all or substantially all of the area of the crown, to reduce the transfer of heat from the crown to the remainder of the piston. The insulation may be by a chamber extending across the piston and the chamber may contain a vacuum. Such a piston can be manufactured by a process involving roll-bonding aluminum or an aluminum alloy to a ferrous material in order to secure a crown of ferrous material to the remainder of the piston made from aluminum or aluminum alloy.