ok. Suchers book states that Indian attempted to breathe more fire into the 1936 four cylinder as it had been basically unchanged since they took over the 4's from the ashes of Ace. so it was basically a 1919 design 4 cylinder (or even older).
so for 1936 they tried an unconventional overhead exhaust valve and a side intake valve which proved "unreliable". further, "as most of these models were sold to law enforcement, the subsequent complaints" led to an attempt improve the design in 37 with a twin carb set up. so thats the deal on the 1936 four cylinders, and I only chose this bike to shoot yesterday at random so there's a surprise around every corner with bike designs. still is I suppose.