One of the many extras you can buy for your Mamod engine are CJW Steam’s adjustable pistons. These enable you to get the piston length within 100 microns of what it should be. We have fitted them to both our SE2a and our SE3. The SE2a’s piston was worn out when she arrived. More bizarrely, the original pistons on the SE3 were actually different lengths! Obviously one of Mamod’s “Friday afternoon jobs“!
Adjustable pistons are slightly heavier than standard pistons. Standard pistons on the SE2a have a mass of 9.2 grams. The adjustable pistons weigh around 9.5 grams – 300 milligrams heavier.