Mach wave Mach wave In fluid dynamics, a Mach wave is a pressure wave traveling with the speed of sound caused by a slight change of pressure added to a compressible flow. These weak waves can combine in supersonic flow to become a shock wave if sufficient Mach waves are present at any location. Such a shock wave is called a Mach stem or Mach front. Thus, it is possible to have shockless compression or expansion in a supersonic flow by having the production of Mach waves sufficiently spaced ("cf." isentropic compression in supersonic flows). A Mach wave is the weak limit
Ford Mustang Mach 1 (for use with 4-venturi carbs) versions. The 351C 4V (M code) engine featured 11.0:1 compression and produced at 5400 rpm. This new performance engine incorporated elements learned from the Ford 385 series engine and the Boss 302, particularly the poly-angle combustion chambers with canted valves and the thin-wall casting technology. For 1971, Ford reduced the content of the Mach 1. The standard features of the model were as follows: In 1971, the Mach 1 was available with three 351 Cleveland engines; the H-code 2-V, the M-code 4-V and beginning in May of 1971, the 351CJ (Cobra Jet or GT engine).