Haynes Engine Construction Kit: What is it? It’s a scale model of a 4-cylinder, 4-stroke petrol engine… that works! &, with its clear casing, you can see how all the parts move inside it. Plus, it has an electronic engine sound & light-up spark plugs. About the product This build-it-yourself kit has everything you need to construct the engine, including all the parts, screws, & a screwdriver. Oh, & detailed, step-by-step instructions with diagrams. How is it powered? There’s no actual petrol involved. This engine runs entirely off 2 AA batteries, which aren’t included. Why you should buy it It’s a super-fun project that teaches you how internal combustion engines work!