 With help from Norton motorcycle racer Don Evans, Devin adapted the cylinder barrels, cylinder heads and pistons from the Norton Manx motorcycle to the two-cylinder boxer Panhard crankcase, roller-bearing crankshaft assembly and piston rods.He then fabricated a custom manifold that accepted two-barrel side-draft Weber carburetors.All of these alterations did not affect the displacement of the engine, leaving the 79.5mm bore and 75mm stroke unchanged for a total displacement of 745 cc.