1978 was the first N6, however there were preproduction models in '76 - 77. If treated fairly Gleaner are a very long life machine. We still sell parts for a few CII's E's, AII's dating back in the 60's that are still in use in somehow.
New holland had twin rotaries out before the N series went to market. IHC had the rotary out and successfull about the time of the N series. The early N's were not as smooth as wanted. Don;t get too serious about an N unless it is 1983 or newer.
I see a picture of the prototype prosessor for the rotor combine over in photo section. I remember seeing a picture of that assembly on the front of a C2 somewhere. Did anyone else see that picture in the landhandler magazine or somewhere elseIJ It would be fun have some pictures of them when proto types were running. I remember checking what some patent numbers were portecting and some of them things didn't show up on a machine for many years.
Try again! The N6 was the first production Gleaner rotary. The N5 and N7 followed. The first prototype was on a combination of a CII and G based machine. Take off the green glasses and read the history that is in print from the Gleaner_AC former employees! The N5 was a lower hp, closed off part of the rotor N6 and the N7 was a larger engine and larger grain tank capacity N6. The 82(Series 3) machines had gotten most of the problems out of the N6 and N7 machines with engine modifictions and heavier built machine.
Allis-Chalmers Farm Equipment 1914-1985 Norm Swinford Page 319-324 ISBNn 0-929355-54-7 Tells all about the development of the Gleaner Rotary under AC with pictures of the N1 on a G base, becoming an N6 and leading to the development of the N5 and N7.