Engine Builder Calculator Suite

Fuel system, compression, boost, airflow, cylinder head, and exhaust calculators for planning engine combinations. Estimates only. Verify final parts with real measurements, dyno data, manufacturer specs, and professional tuning.

Fuel Injector Sizing

Calculates injector size from horsepower, injector count, duty cycle, and BSFC preset.

Injector cc/min conversion uses a gasoline approximation of 1 lb/hr ≈ 10.5 cc/min. E85 and methanol vary because fuel density differs.

Fuel Pressure Flow Correction

Corrects injector flow when changing base fuel pressure.

Compression Ratio

Calculates static compression ratio and includes head gasket thickness, gasket bore, deck clearance, piston dish, valve relief, or dome volume.

Use positive piston CC for dish/valve relief. Use negative piston CC for dome pistons.

Engine Displacement

Calculates cubic inches, cc, and liters from bore, stroke, and cylinder count.

Mean Piston Speed

Calculates average piston speed from stroke and RPM.

Effective Compression Under Boost

Rough effective compression estimate based on static compression and boost pressure.

This is not mechanical compression ratio. It is a rough cylinder-pressure risk comparison.

Supercharger Pulley Speed

Calculates blower RPM from crank pulley, blower pulley, and engine RPM.

Supercharger Boost Estimate

Rough boost estimate for roots/twin-screw style positive-displacement superchargers.

Actual boost depends on belt slip, camshaft, leakage, intercooler restriction, exhaust flow, altitude, and temperature.

Turbo Airflow / Pressure Ratio Helper

Estimates pressure ratio, CFM, and lb/min airflow for turbo sizing.

Intercooler Temperature Estimate

Estimates compressor outlet temperature and after-intercooler temperature.

Airflow / Carb / Throttle Body

Estimates engine airflow requirement, throttle body area, and rough horsepower support.

Valve Area / Curtain Area

Compares intake and exhaust valve face area and valve curtain area.

Cylinder Head Flow to Horsepower

Estimates naturally aspirated horsepower potential from intake flow and cylinder count.

Airflow Restriction Finder

Compares throttle body area, runner area, and valve curtain area to find the likely smallest cross-section.

Exhaust / Header Size Calculator

Recommends header primary diameter, primary length, collector size, and main exhaust pipe size.