Calculate engine intake diameter or solve VE, CID, RPM, or intake air velocity from the other four inputs with unit conversion options.
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Engine Intake Diameter Formula
The following equation is used to calculate the Engine Intake Diameter.
D_1 = \sqrt{\frac{(VE/100)\cdot CID \cdot RPM \cdot 144 \cdot 4}{S \cdot 88 \cdot 3456 \cdot \pi}}- Where D1 is the engine intake diameter (inches)
- VE is the volumetric efficiency (%)
- CID is the engine displacement (cubic inches)
- RPM is the engine speed (revolutions per minute)
- S is the intake air velocity in the intake tract (miles/hr)
What is an Engine Intake Diameter?
Definition:
The engine intake diameter is the inside diameter of a (typically round) intake passage that air flows through on its way into the engine (for example an intake tube/duct, throttle body opening, or a round runner equivalent). It is not the cylinder bore.
