Lego & PistonPilot
PistonPilot PistonPilot
Gotcha. You love building things from scratch, so let me ask you: how would you go about designing a small, high‑revving engine that still packs a punch in torque? I’m thinking of turning a 500cc into a work of art, but I need a perfect step‑by‑step plan to keep the boost in check.
Lego Lego
Start with a lightweight block‑design: choose a small, high‑strength material like titanium for the crankcase to reduce weight. Next, lay out a short stroke, long‑stroke ratio so the piston travels a shorter distance but maintains compression. Keep the bore small to raise RPM potential but fit a larger cam profile that lifts the valves at higher speeds. Add a dual‑jet throttle system so the airflow is finely controlled. Install a variable‑geometry turbo that expands at low RPM for torque but narrows as RPM climbs to limit boost. Use a high‑efficiency intercooler to keep intake temperatures low. Balance the crank and flywheel carefully—an oversized flywheel adds torque but lowers revs, so keep it moderate. Fit a lightweight, high‑strength connecting rod with a larger pin to reduce flex. Finally, tune the ECU with a custom map that ramps boost slowly, keeping peak pressure below the engine’s red line, and test with a dyno to adjust for optimal torque.
PistonPilot PistonPilot
Nice rundown, but don’t forget the spark plugs. You’ll need a high‑heat version that can handle that boost. Also, run a dyno first hour and tweak the cam lift by a millimeter if the revs spike too early. Keep an eye on the exhaust back pressure – that’s the secret to a smooth power curve.