Nasty Fast Parts · Two-Stroke Tech Tools
Compression & Squish with Squish Velocity Estimator v84
Cylinder volume, geometric and corrected compression, squish band geometry and an estimated squish-flow curve.
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Cylinder & Chamber
Enter measured engine geometry. The chamber volume is the total measured clearance at TDC, including the installed plug equivalent.
Use actual rod center-to-center length.
Measured with piston at TDC; includes all head/piston geometry.
Symmetric exhaust timing used for corrected compression.
Measure with solder at multiple points; cold static value.
Radial band width from bore edge toward chamber.
Calculated Geometry
Estimated Squish-Flow Velocity
An incompressible kinematic approximation. Actual maximum squish velocity depends on combustion-chamber geometry, pressure, swirl/turbulence and gas compressibility.
This is not a validated MSV measurement and is not a safe-clearance threshold. Check piston-to-head contact, crank/rod growth, bore, fuel, thermal expansion and manufacturer recommendations.