Current testing requirements for high temperature alloys are defined in general industry specifications (ASTM, AMS), as well as in user specifications. Many of these requirements were established in the 1960's when production practices were yet to be refined.
cowling - protective covering consisting of a metal part that covers the engine; there are powerful engines under the hoods of new cars; the mechanic removed the cowling in order to repair the plane's engine.
Engine size refers to the volume of the cylinder bores. For example; A common ford V-8 engine is the the 3.0. This is 3.0 liters or about 302 cubic inches in volume. Volume of an engine is the displacement of the stroke from top dead center to bottom dead center. it is simple mathematics. Cylinder bore in a ford 3.0 liter is 4 diameter. So the displacement of the engine is 302 cubic inches or 3.0 liters. This is only an example but I hope it helps. Cubic cinntemeters is the measurement of the combustion chamber in the cylinder head. The air fuel mixture from the cylinder bore is compressed into the combustion chamber of the cylinder head and ignited.