Method of Assembling an internal combustion engine

A method of assembling an internal combustion engine using a piston ring compression fixture, said engine comprising a crankcase having an open top for receiving a crankshaft and a closed bottom, a crankshaft with a plurality of attached connecting rods, said connecting rods having attached pistons with piston rings, and an extruded cylinder block with a flat bottom surface and flat top surface with a cylinder bore for each of said pistons extending through the block from said top to said bottom surfaces, said method comprising the steps of:

• positioning said crankcase with its open top upright to receive said crankshaft with attached connecting rods and pistons through said open top, said open top being generally flat and defining a plane;
• placing said crankshaft through said open top to rest on said closed bottom of said crankcase with said pistons and piston rings and a portion of said connecting rods extending above said open top;
• locating said pistons and rings at a common level above the plane of said open top of said crankcase;
• simultaneously compressing all of said piston rings with said compression fixture;
• locating said cylinder block over said fixture with said cylinder bores each aligned with a piston whereby said flat bottom of said block lies in a plane parallel to said crankcase open top plane;
• inserting said pistons with the compressed rings into the bores of said block;
• removing said compression fixture;
• and
• lowering said block with said inserted pistons for attachment to said crankcase.

A method of inserting a plurality of pistons with piston rings in an extruded cylinder block, said pistons having co-planar top surfaces and said block having a flat bottom surface with a cylinder bore therein for each of said pistons, said method comprising the steps of:

• simultaneously compressing said piston rings on all of said pistons to fit into said cylinder bores;
• placing said block with respect to said pistons so that its bottom surface is in a plane parallel to said co-planar piston top surfaces;
• and
• inserting said pistons through said bottom surface into said cylinder bores with said pistons rings being released from said compression as the rings enter said bores.