**Contents**show

## How is engine capacity calculated?

**Calculation of motor capacity**

- n = i x n1. n : Motor speed (min–1) n1 : Speed of gear output shaft or pulley etc. attached to it. i : Reduction ratio of gear head (e.g. i = 20 for 1/20)
- 1) Set the suitable SPEED.
- 2) Voltage calculation.
- 3) Torque measurement.
- 4) Set the speed torque.

## How much CFM do I need for engine?

The formula for calculating how much CFM (cubic feet per minute) your engine requires is: **CFM = Cubic Inches x RPM x Volumetric Efficiency ÷ 3456**. Any ordinary stock engine will have a volumetric efficiency of about 80%.

## How do you calculate the mechanical load of a motor?

In our example input electrical power of the motor is 0.22 A x 6 V = 1.32 W, output mechanical power is 1000 rpm x 2 x 3.14 x 0.00126 N•m /60 = 0.132 W. Motor torque changes with the speed. At no load you have maximum speed and zero torque. Load adds mechanical resistance.

## How do you calculate torque needed?

To calculate load torque, **multiply the force (F) by the distance away from the rotational axis**, which is the radius of the pulley (r). If the mass of the load (blue box) is 20 Newtons, and the radius of the pulley is 5 cm away, then the required torque for the application is 20 N x 0.05 m = 1 Nm.

## How is motor power calculated?

Calculate the power the motor consumes while in operation. The equation is **W = AV(sqrt 3)** where A is amperes, V is volts, and sqrt 3 is the square root of 33 (about 1.73). W is the power consumption in watts. For example, if the electric motor uses 50 amps at 240 volts, the wattage is 50 x 240 x 1.73, or 20,760 watts.

## How do you calculate the power developed by the engine?

The power developed by an engine at the output shaft is called brake power and is given by **Power = NT/60,000 in kW** where T= torque in Nm = WR W = 9.81 * Net mass applied in kg.

## How do you calculate motor horsepower?

The quickest method to closely estimate motor horsepower is to use a digital clamp meter to measure current and voltage to the motor, and then perform a simple calculation. Use this formula to estimate motor horsepower. Horsepower**(hp)= Voltage x Amperage x % EFF x power factor x 1.73/746**.

## How do you calculate motor horsepower from CFM?

If you know how much horsepower your motor makes, you can **estimate its air flow in** cubic feet per minute (CFM). For example, a 1,600 cc motor in a good state of tune requires about 54 cubic feet per minute to make 78 horsepower.

## Is 600 cfm carb big enough?

A 600-cfm carburetor may perform quite well on a **stock 350 Chevy**. However, the minute you start weaving in power adders like a hotter cam, a dual-plane performance intake manifold, and aluminum heads you’re going to need 700-750 cfm.