Comments by "Beer_Dad" (@Beer_Dad1975) on "Rolls Royce Made A Diesel Rotary Engine With Four Rotors!" video.

yeah, but 2 of the rotors are actually just compressing the intake charge using the energy from the exhaust of the other 2 rotors - so really its just a 2 rotor, twin turbo charged engine that is using integrated rotary turbo chargers.
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Technically supercharges run off direct mechanical force like a drive shaft or pulley, turbo charges run off exhaust gasses as this does (unless it is also somehow mechanically connected to the two combustion cycle rotors? I didn't get that from the video though), so this would fall more closely into turbo charger- though I guess it's really not quite either. With that huge rotating mass I expect lag would be pretty horrific - maybe not an issue in the applications they were looking at using it on.
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Yeah, I'm really not sure now you might be right - I just can't really picture how you could efficiently connect the two separate eccentric shafts together, so I assumed they are not connected and the larger rotors are being driven only by the exhaust gasses. I assume that is why it possibly never went anywhere, since a small, lightweight turbine is probably going to be far more efficient than a gigantic heavy rotor - which is why modern diesel engines don't weigh 1000lb for 350bhp. Personally I think if the rotary was going to take off, it would have done so already - but who knows, someone might come up with some new materials or processes that allow manufacturers to overcome the various problems they have with durability, emissions and efficiency.
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Would you really call the compressor rotor part of the combustion system? Isn't it really just an integrated rotary turbocharger? It doesn't actually have any ignition phase does it? So this is really a twin turbo charged two rotor.
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