With a quantity of four pieces, the Washer, Protecter is the most used part in the ALTERNATE (ENGINE) diagram.
Of all the components that make up this Alternate (engine) the Screw, Tapping (30x) has the lowest price.
Some items from this specific schematic: Screw, Bind (844), Pipe, Exhaust 1, Bolt, Flange (4h3), Muffler 1.