if it's possible would it be cost effective? Do you really think those small ones have the grunt to keep up with a 4/55K Onan?
Sure they'd keep up with the Onan if you built in enough power. Water cooling would allow encapsulation. Twin cylinder engine would have smaller quieter exhaust pulses. Inverter would keep RPM down if possible. They could even tap the coach batteries for surges like the Yamaha boost does. Cost would be up but a good design would last for a decade or more-spreading out costs. Those who want to pay for it would buy it and cut the overall campground noise. The cost would not be excessive.
This would be night and day compared to current tech. Many people would want to buy it.
