Thermal Efficiency
28.4%
Peak efficiency region
Surface / Volume Ratio
0.42 cm⁻¹
Quench Heat Loss: 14.2%
Apex Seal Tip Speed
28.5 m/s
Limit threshold: 45 m/s
Thermal Warpage / Blow-by
1.2%
Housing expansion delta
Scaling Landscape & Sweet Spot (250 - 700cc)
Active: 500cc
Why Wankels Don't Scale:
- Below 250cc (Micro-Rotary): Extreme surface-to-volume ratio quenches the flame front against cold metal walls. Combustion fails to finish before the long combustion chamber expands.
- Above 700cc (Macro-Rotary): Rotor tip velocity exceeds 45 m/s. Centrifugal force and thermal gradients warp housing apex paths, inducing extreme apex seal wear and blow-by gas leakage.
- 250cc–700cc Sweet Spot: Optimal balance of thermal retention, seal life, and volumetric power density.