Abstract: A modified barrel device (1) and method of retarding injection timing of EMD-type unit injectors by a desired amount of crank degrees includes the steps of providing a modified pump barrel (8) whose port locations differ, in their spacing from the top shoulder of the associated barrel, that corresponds to the spacing from the top face of the associated follower, from the spacing of the barrel port sealing location of the pump barrel of the original injector from the top shoulder of the associated barrel, that corresponds to the top face of the associated follower (2), such difference in spacing being by an amount equal to the amount of retardation, in linear units, that corresponds to the desired amount of retardation in crank degrees, and assembling the modified pump barrel (8) into an injector assembly.

Abstract: A modified pump follower device (2) and method of retarding injection timing of EMD-type unit injectors by a desired amount of crank degrees includes the steps of providing a modified pump follower (2) whose plunger engagement location, also known as t-slot (7), varies depending on the desired amount of retarding. Specifically, the modified pump follower (2) has a t-slot (7) which has a predetermined distance t? on the modified pump follower (2), as compared to conventional pump followers having a predetermined distance t, such that the t-slot (14) is closer to the top face (9) of the pump follower (2). The difference in spacing between the original timing t and the retarded timing t? is r, which is an amount equal to the amount of retardation, in linear units, that corresponds to the desired amount of retardation in crank degrees.