Mean Piston Speed and RPM-Limit Reading

MPS = stroke_in x RPM / 6 (ft/min), independent of bore. A 3.48 in stroke at 6,000 rpm runs 3,480 ft/min (street/endurance); rev to 7,000 and it hits 4,060 (performance) - and a longer 4.00 in stroke would already sit at 4,000 at 6,000 rpm, the trade a stroker accepts. Street builds stay under ~4,000, performance 4,000-4,500, race over 4,500. Average, not peak; guidance bands. A shop aid; the component ratings govern.

mps_fpm = stroke_in x RPM / 6 (= 2 x stroke x RPM); mps_ms = mps_fpm x 0.00508; regime by ft/min band.

The mean-piston-speed relation MPS = 2 x stroke x RPM and the practical rpm-limit bands, as compiled in the engine-building references, by name.

The mean-piston-speed relation is a public engine-building result; the regime bands are standard builder guidance.

Estimate. AHJ and licensed professional govern.

Field names used by the API: stroke_in, rpm, mps_fpm, mps_ms

• Mean speed MPS = stroke_in x RPM / 6, the average piston speed over a strokeengine-building references
• Regime bands street/endurance under ~4,000, performance 4,000-4,500, race over 4,500 ft/minbuilder guidance
• Average not peak peak is roughly pi/2 higher and rod-ratio-dependent; not computed herekinematics