Dang...there are sure some misconceptions as to how Detroits run
First...ALL 2 stroke Detroits from the lowly 2-51 series with velvet lined blower rotors [as rare as hens teeth!] including the 53/71 series and all the way to the mighty quad tubo 16 v 92 and 149 series have blowers---Detroits do not have intake valves so the air has to come from somewhere!
But the majority do have 4 exhaust valves per cyl....... there are some 2 valve units out there -71 series that are prolly older than most who post here
Secondly...Inline Detroits-53 and 71 series have the ability to be configured with blower/exh on same side or opposite and in both right and left hand rotation.
Third...are they screamers...ABSOLUTELY!
They have been called Screamin' Jimmys...Double Breasted Yamahas.... Buzzin Dozens [12 V's in rock haulers] etc....
Fourth...Detroits "Overspeed"...............It's the mis-informed mechanics who "Run Away"!