turbo compound engines thanks for your message i know little about formula or what they're up to these days there's relatively little use of it in the ' s for aircraft and that's fairly well known except the r r griffon which had some experimental use as a turbo compound but is still in the archives what i can add is about the origins in the s diesels were undergoing substantial development high speed diesels were having forced induction applied particularly in work by saurer there was an effort to see just how much boost was practical in contrast to petrol engines it was found that it was relatively easy apply a high boost of maybe bar without problems such as detonation these high boost engines were mostly using centrifugal superchargers what then became a problem was how to extract mechanically all of the extra thermodynamic energy released the engine was now running with an effective compression ratio far in excess of the piston's mechanical compression considering the piston power stroke as an expansion phase in a heat engine there just wasn't enough stroke or expansion for the combustion gases to do enough work on the crankshaft the exhaust still remained hot and pressured with much of the energy still remaining in it a solution was the turbo compound by running the exhaust through an expansion turbine more of this energy could be extracted turbo compounds were difficult though just coupling the fast turbine shaft to the slow crankshaft was a problem especially as there really needed to be a variable speed drive in there too what was realised though was that driving the mechanical supercharger required substantial power about as much power as could easily be extracted from the exhaust turbine so coupling one to the other directly provided a neat solution to supercharger drives and avoided the need for turbo compounding the exhaust turbine this was effectively a parallel evolution to the buchi turbocharging system that had been tried some years earlier and would now become the dominant approach for supercharging large four stroke diesels at constant loads two strokes in vehicles usually stuck with roots blowers as they gave better scavenging at low speeds as to the other matters then yes i've probably given up as a contributor to wikipedia one admin stated that it would be better if i were blocked than betacommand and the other has told me that he considers me de facto banned anyway and will indef block me if i post to ani again