1924 Douglas Over Head Valve Engine. Turns over with tons of compression. From my research this is a model OB 600cc.
Carburetors I don't think are correct. S ee pictures for details and condition.Be sure to check out all my listings and items in my store. The item "1924 Douglas OHV 600cc Engine Model OB racer flat grass track antique motor" is in sale since Sunday, October 14, 2018. This item is in the category "eBay Motors\Parts & Accessories\Motorcycle Parts\Antique, Vintage, Historic". The seller is "crazyleeroy" and is located in Mulino, Oregon. This item can be shipped to United States.