Piston wrist pin installation tool and method

A wrist pin installation kit comprising:

• a hollow cylindrical sheath having an inner circumference less than a compressed outer circumference of a wrist pin clip when the wrist pin clip is installed, wherein an outer diameter of the cylindrical sheath is less than a diameter of an access hole provided through an outside wall of an engine block of an engine, the access hole positioned so that a wrist pin aperture in a wall of a piston of the engine is alignable with the access hole when the piston is installed within the engine;
• a flange having mounting holes configured for installation of bolts to secure the flange to pre-formed mounting holes of the engine block, wherein the flange has an integral collar having an inner diameter greater than the outer diameter of the cylindrical sheath, whereby the cylindrical sheath is insertable through the collar to contact the wall of the piston, wherein the collar has a tightening mechanism for securing the cylindrical sheath against the wall of the piston during installation of the wrist pin and the wrist pin clip, wherein the tightening mechanism comprises a threaded cap turned onto exterior threads of the collar and having a hole through a top of the cap having a diameter greater than the outer diameter of the cylindrical sheath and a conical split washer having a conical outer face with a tapered end inserted partially into the end of the collar, whereby when the threaded cap is tightened against the conical split washer, an inner face of the conical split washer tightens against the cylindrical sheath to secure the cylindrical sheath against movement during installation of the piston wrist pin;
• a rod having a diameter less than an inner diameter of the cylindrical sheath and having an end portion sized to insert within an inner diameter of a piston wrist pin and a body portion sized to slide within the cylindrical sheath, whereby the rod is insertable through the cylindrical sheath with the wrist pin and the wrist pin clip fitted over the end portion with the wrist pin clip at a distal end of the body portion so that when the wrist pin is slid entirely within the piston, the wrist pin clip is released from the cylindrical sheath and expands to secure the piston wrist pin within the piston, whereby the rod and the cylindrical sheath can be slid out from the collar with the secured piston wrist pin remaining installed in the engine;
• and
• an alignment tool having a tapered end for insertion within the collar for aligning the wrist pin aperture of the piston with the access hole prior to installation of the wrist pin and the wrist pin clip using the cylindrical sheath and the rod.

A method of installing a wrist pin and wrist pin clip in a piston of an engine:

• assembling the piston and corresponding rod within the engine;
• aligning a wrist pin aperture of the piston with an access hole provided through an outside wall of an engine block of the engine and positioned to access a wrist pin aperture of the piston using a tool having a cylindrical sheath with an inner circumference less than a compressed outer circumference of the wrist pin clip when the wrist pin clip is installed, wherein an outer diameter of the cylindrical sheath is less than the diameter of the access hole;
• mounting a flange of the tool to the engine block by bolting the flange through preformed mounting holes of the engine block, wherein the flange has an integral collar having an inner diameter greater than an outer diameter of the cylindrical sheath;
• inserting a hollow cylindrical sheath having an inner circumference less than a compressed outer circumference of an installed wrist pin clip into the engine block and against the wrist pin aperture of the piston;
• inserting a rod having a diameter less than an inner diameter of the cylindrical sheath and having an end portion sized to insert within an inner diameter of a piston wrist pin and a body portion sized to slide within the cylindrical sheath into the cylindrical sheath with the wrist pin and the wrist pin clip fitted over the end portion with the wrist pin clip at a distal end of the body portion;
• tightening a tightening mechanism to secure the cylindrical sheath against the wall of the piston during the inserting of the cylindrical sheath and the rod, wherein the tightening mechanism comprises a threaded cap turned onto exterior threads of the collar and having a hole through a top of the cap having a diameter greater than the outer diameter of the cylindrical sheath and a conical split washer having a conical outer face with a tapered end inserted partially into the end of the collar, whereby when the threaded cap is tightened against the conical split washer, an inner face of the conical split washer tightens against the cylindrical sheath to secure the cylindrical sheath against movement during installation of the piston wrist pin;
• sliding the wrist pin entirely into the piston, releasing the wrist pin clip from the cylindrical sheath so that the wrist pin clip expands to secure the piston wrist pin within the piston;
• and
• sliding the rod and the cylindrical sheath out from the collar with the secured piston wrist pin remaining installed in the engine.