Our good friend, Bill Irwin, made a piston and rod holder out of tubing to cleanly retain pistons and rods while assembling a short-block. This is a great idea since most lightweight pistons and rods often won’t sit vertically on the bench. This homemade piston holder keeps the pistons and rods off the bench surface and in proper order until assembly.
We’ve discovered it is especially useful to keep the pistons from not laying on their side when using thin oil ring packages. It’s very easy to push these tiny rings out of their ring lands if the piston lies on its side. So keeping the piston upright will prevent this from happening.
Bill made this holder out of scrap stainless tubing in his shop. But it seems to us that you could be just as creative with some simple PVC tubing and glue to build a similar tool, with the added advantage of being a non-marring material. Another thought that has crossed our minds when thinking about these, is slotting a polymer cutting board as the top. They are readily available on Amazon, in various thicknesses and colors, and would cut easily enough with just about anything capable of chucking up an endmill.
Wood is always another option, be it with boards, dowels, or sheets. While it may not look quite as cool as this stainless steel piece, it will still get the job done. Ultimately articles such as these are about getting your creative juices flowing and seeing what comes out of your shop. Homebrew tools are some of the coolest things you’ll find in any shop you visit, so get to building!