Issue link: http://www.e-digitaleditions.com/i/536502
July / August 2015 14 TECHNICAL EDITOR By Karl Wilen I left off at the end of the last article with our 2.5L M96 Boxster engine ready for piston install on the bank 2 side. Since at this point the two case halves are together, we can not just insert a piston and rod down through the cylinder and attach the rod cap at the other end like we did with bank 1 because the case is enclosed! So the Bank 2 side is a bit more tricky. When I assembled the case halves, I already have the rods installed on the crankshaft, so now we need to connect the piston to the rod via the wrist pin, a bit backwards if you have every rebuilt an engine before. The idea is that we need to line up the piston and rod end, slide in the wrist pin that connects the two, and then insert a wrist pin clip into the piston to keep the wrist pin from sliding out. The question is, how do we do that with an enclosed engine? So here is a picture of our piston with a wrist pin in place for illustration. Then the wrist pin clip will install in the groove next to the wrist pin and keep it all together. We are going to insert the piston in the cylinder from the top like normal using a ring compressor as we did on bank 1. You can only do one cylinder at a time all the way to completion before moving to the next one (5, then 4) Theses are the tools that are going to be used to accomplish this. One is a hollow tube, and the other is a solid insertion rod. Insert the wrist pin onto the insertion rod end as so. Rotate the engine so that bank 2 is pointed at the ground, this will allow the rod end to pendulum easily and line up with the piston. Once everything is lined up, slide the wrist pin into the piston via a small access hole in the front of the engine. You will have to rotate the crankshaft to get the rod end to line up with the hole. Photos by Karl Wilen Not As Easy As JUST ADD WATER - II