V8 Intake Port Drop Calculator

When you're building a custom intake manifold or matching ports between heads, getting the port drop right is critical for good port alignment and airflow. This calculator works out exactly how much material needs to come off the head face to achieve your desired port drop, based on your engine's V-angle and head face angle.

Select a standard V-engine configuration (90° small block, 60° V6/V12, 65° Porsche, 72° Yamaha, and more) or enter a custom angle, then input your head face angle and desired port drop. The calculator returns the exact material removal figure and shows you the resulting intake V-angle between the two ports.

Works in imperial or metric, and includes pro tips on measurement technique and common head face angle conversions.