It could very well be a Mach .26. The S is for Sportwerks. In many cases, engines are made by one company for multiple companies. The Werks P3 is the EXACT same as the Ofna outlaw .26 and the Team Orion Wasp .26. Another example, the Orion Wasp .28 and the Peak Diablo .28 are the same engine. They all carry different side stamps for the different companies, but are the exact same engine. Dynamite could have made the Sportwerks .26 and put the S logo on the side.