Tools for engine builders

The engine's theoretical air demand in CFM.

Theoretical maximum flow and flow efficiency for the head.

Theoretical maximum flow in CFM for two intake valves.

Air velocity at a second cross section via continuity.

Tuned runner length for the right torque peak in the range.

Port volume in cc from average area and port length.

Minimum port area (MCSA) for a chosen air velocity.

Average cross-sectional area for a twin-cam intake channel.

Theoretical port flow in CFM from port area and flow factor.

Air velocity in the port from flow and cross-sectional area.

Volume and taper angle for a tapered intake runner.

Throttle body diameter in mm for your target power.

Mean velocity through the valves and valve/bore ratio.

The lift where the curtain area meets the port's minimum cross section.

Static compression ratio from all the volumes in the head.

Static compression ratio worked out from the whole rotating assembly's stack-up.

Pressure ratio P2/P1 and airflow from the boost.

Estimated boost for a Roots blower.

The right injector size in cc/min for your target power.

Required fuel flow in l/h for your target power.

Required CFM and carburettor size for the engine.

Cylinder volume, displacement and total capacity from bore, stroke and cylinders.

Mean piston speed in m/s from stroke and rpm.

Rod ratio from rod length and stroke.

Stack the rod, pin height and stroke and solve the piston-to-deck clearance.

Guiding cold clearance for main and rod bearings.

Ring gap for the top, second and oil ring by application.

Convert ET to trap speed and estimate the power from weight and speed.