Abstract: An engine is provided with hydraulic valve lifters and other valve train components, wherein the invention consists of a tool which utilizes the engines existing valve train components to determine if the correct adjustment is present to provide for the proper clearances of the hydraulic valve lifters. Several embodiments are disclosed, including gauge only embodiments and embodiments which include adjusting and gauging functions.

Abstract: An ion thruster beam shield is provided that comprises a cylindrical housing that extends downstream from the ion thruster and a plurality of annular vanes which are spaced along the length of the housing, and extend inwardly from the interior wall of the housing. The shield intercepts and stops all charge exchange and beam ions, neutral propellant, and sputter products formed due to the interaction of beam and shield emanating from the ion thruster outside of a fixed conical angle from the thruster axis. Further, the shield prevents the sputter products formed during the operation of the engine from escaping the interior volume of the shield.