This unique example of a "Marion" 8-valve was purchased from
Indian, sometime in the 1920's, by Waldo Korn who had ridden
professionally for both Indian and Excelsior. In the 1940's Korn
sold this machine to the legendary Peoria, Illinois racer and tuner
Dewey Simms who, until the late 1950's or early 1960's, rode a
demonstration lap with it at the famous Springfield Mile.
On this drive-side view,  notice the "tunnel" fabricated into the oil
tank to allow clearance for the rear cylinder's exhaust pipe.