1275 cc · Single HIF38 · 1.50 in · naturally aspirated
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PEAK POWER59.0 bhp
@ 5,250 rpm
PEAK TORQUE93.6 Nm
69.0 lb ft · @ 3,500 rpm
MODELLED INSTALLED INLET FLOW99 cfm
Combined effective flow ceiling · not a catalogue carburettor rating
RECOMMENDED MAX SPEED5,700 rpm
6,500 rpm mechanical limit · peak power 5,250
CALCULATED OUTPUT
Power & torque curve
● Power (BHP)● Torque (lb ft)
CLASSIC MINI PERFORMANCE
Vehicle estimates
Flywheel59.0 bhp
At wheels48.4 bhp
Peak torque93.6 Nm · 69.0 lb ft
Specific output46.3 bhp/L
Predicted maximum speed90.7 mph
Power-limited speed90.7 mph
Theoretical gearing limit104.2 mph
Top gear16.0 mph/1k
0–60 mph13.3 sec
Quarter mile · 1 ft rollout19.3 sec
COMPLETE PACKAGE ASSESSMENT
Cam is restricted by the airflow package
Only 41% of the cam's calculated potential is being realised because the surrounding airflow path cannot support it.
Cam effectiveness realised41%
Carburettor airflow reserve6%
Cylinder-head airflow reserve23%
Higher reserve means unused capacity at peak power. Low reserve means closer to the calculated flow ceiling; it does not automatically mean the component must be replaced.
Closest airflow restrictionCarburettor and inlet pathSingle HIF38 · 1.50 in provides 99 cfm with 6% reserve. The selected head path provides 122 cfm with 23% reserve.Mechanical ceiling6,500 rpm · Rotating assemblyRotating assembly 6,500 rpm; valve control 6,500 rpm. Peak power is at 5,250 rpm with 1,250 rpm margin.Fuel and mixtureWithin the modelled power band at 12.8:1 AFR2.4 RON reserve above the 94.6 RON requirement. Verify under load with a wideband sensor and knock-safe ignition testing.Evidence and confidence68% model confidenceFactory-anchored estimate · 1275 GT / standard 1275 specification. Factory specifications anchor the standard engine; modifications retain the calculated airflow and combustion change relative to that baseline.
Most useful conclusionThe cam is being restricted. Address the carburettor and inlet path first; a larger cam alone will not bypass it.
Current cautions
Selected redline is mechanically permissible but above the calculated 5,700 rpm useful maximum for a 5,250 rpm power peak.