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.
A flathead engine (a.k.a. sidevalve engine (SV), flathead, or flatty) is an internal combustion engine with valves placed in the engine block beside the piston, instead of in the cylinder head, as in an overhead valve engine. As the cylinder cross-section has the shape of an inverted L, other names such as L-block or L-head are also common. The sidevalve's poppet valves are usually sited on one side of the cylinder. A recess in the cylinder head creates a corridor connecting the valves and the c