Building a Stirling Engine Bike

Tom Stanton

This video has been trending in United Kingdom

The video documents the complete journey of turning an ordinary bicycle into a functional Stirling-engine-powered vehicle. It opens with the creator explaining the allure of external-combustion engines and the challenge of extracting enough power from a traditionally low-output Stirling design. After outlining the basic gamma-type layout, he sketches the drivetrain strategy: a belt system connected to a large rear sprocket to multiply torque while keeping RPM in the optimal efficiency range. Viewers get a concise review of the thermodynamic cycle—heating, expansion, cooling, contraction—as the foundation for every hardware decision that follows.

Fabrication starts with the hot-side cylinder cast from aluminum for its thermal conductivity, then honed on a lathe to micron-level tolerances. A displacer made of lightweight stainless steel wool is suspended on a graphite rod to minimize friction and resist heat. The power piston is machined from low-expansion cast iron, fitted with custom PTFE rings, and paired with a polished glass cylinder so leaks are visible during testing. A massive steel flywheel is balanced to smooth the power pulses, while a laser-cut regenerator matrix boosts efficiency by temporarily storing heat between strokes. Each component is test-fitted and measured with calipers, emphasizing the importance of airtight seals and minimal dead volume.

With the core engine assembled, attention shifts to the combustion system. A pressurized propane burner, similar to a jet stove, is bolted under the hot cap and surrounded by ceramic insulation to maintain a steady 600 °C surface temperature. Thermocouples and a Pi-based data logger monitor hot-side and cold-side temperatures in real time, allowing on-the-fly tweaks to burner pressure and cooling fan speed. Once bench tests confirm 450 W output at 800 RPM, the engine is transplanted onto the bike frame. Custom aluminum plates anchor the crankcase to the bottom bracket, and a one-way clutch hub lets the rider coast when the engine idles.

The video culminates in street trials. After a few pulls to overcome initial friction, the engine fires, the flywheel stabilizes, and the belt drive propels the bike up to 30 km/h on level ground. The narrator highlights lessons learned: maximizing the temperature differential, using low-friction materials, and gearing for torque rather than speed. He ends by inviting viewers to iterate on the design—experiment with solar concentrators, biomass burners, or liquid-nitrogen cooling for higher delta-T—showing that the Stirling engine bicycle is not just a one-off novelty but a platform for sustainable, curiosity-driven engineering.

Share Video

¿Do you like Building a Stirling Engine Bike? Share it with your people...

Playlist