Engine Base¶

Bore, stroke, and cylinder count set displacement; fuel type selects the ECU. This is the foundation every other part builds on.

What it is¶

The engine base defines the fundamental geometry: bore (cylinder diameter), stroke (piston travel), and number of cylinders. From these the sim computes displacement:

\[\text{displacement} = \frac{\pi}{4} \times \text{bore}^2 \times \text{stroke} \times \text{cylinders}\]

The base also sets the fuel type — petrol or diesel — which selects the corresponding ECU, and carries the engine's recommended octane and maximum RPM.

Why it matters¶

Everything downstream scales from the base:

Displacement is the single biggest factor in how much air (and therefore power) the engine can move — it's the displacement/2 term in speed-density.
Bore/stroke ratio shapes character: a big bore / short stroke revs higher and breathes well up top; a long stroke favors low-end torque.
Fuel type is a fork in the road: petrol gets spark ignition, diesel gets compression ignition and the diesel ECU.

How to tune it¶

Choose the base for your target. Want big power? Displacement is the easiest route. Want a high-RPM screamer? Favor a larger bore and shorter stroke. Set the recommended octane to match the compression you intend to build.

Rule of thumb

"There's no replacement for displacement" — a bigger base makes every other gain easier. But it also raises the bar for fuel and breathing to keep up.

In the game¶

The base is chosen on the Setup page. Displacement, compression, and redline update as you change it and the parts around it.