Internal combustion engine working volume calculator

The cylinder working volume represents the volume located between the extreme positions of the piston movement.

The cylinder calculating formula is known from the school curriculum — the volume is equal to the product of the base area and the height. And in order to calculate the engine volume of a car or motorcycle, you also need to use these multipliers. The working volume of any engine cylinder is calculated as follows:

when,

h — piston stroke length mm in the cylinder from UDС to LDС (Upper and Lower Dead CENTERS)

r — piston radius mm

n — 3.14 not a nominal number.

How to find the engine capacity

To calculate the engine capacity, you will need to calculate the volume of one cylinder and then multiply by their number at the engine. And it turns out:

V shift = number Pi multiplied by the square of the radius (piston diameter) multiplied by the height of the stroke and multiplied by the number of cylinders.

Since, as a rule, the piston parameters are indicated everywhere in millimeters, and the engine capacity is measured in cm., so to convert units, the result will have to be divided by another 1000.

Please note that the total volume and the working volume differ, since the piston has bulges and undercuts under the valve and it also includes the volume of the combustion chamber. Therefore, do not confuse these two concepts. And in order to calculate the real (full) volume of the cylinder, you need to sum the volume of the chamber and the working volume.

You can determine the engine capacity using a standard calculator, knowing the parameters of the cylinder and piston, but calculating our working volume in cm³ will be much easier and faster online, especially if you need calculations to find out the engine power, since these figures are directly dependent from each other.

The internal combustion engine volume calculation

To calculate the engine volume that is interested to you, you need to enter 3 digits into the appropriate fields — the result will appear automatically. All three values ​​can be found in the passport data of the car or in the technical characteristics of a particular part or determine how much piston caliper will help.

Thus, if for example you have turned out that the volume is equal to 1598 cm³, then in liters it will be designated as 1.6 liters, and if the number of 2429 cm³ came out, then 2.4 liters.

Long stroke and short stroke piston

Also note the fact that with the same number of cylinders and the working volume of the engines may have a different diameter of the cylinders, the piston stroke and the power of such motors will also be different. The engine with short-stroke pistons is very voracious and has low efficiency, but reaches great power at high speed. And the long-stroke ones are placed where thrust and economy are needed.

Consequently, the question “how to find out the engine volume by horsepower” can be given a firm answer — by no means. After all, although horsepower has a connection with engine capacity, it’s impossible to calculate it from them, since the formula for their interrelationship still includes many different indicators. So it is possible to determine the cubic centimeters of the engine solely by the parameters of the piston.

Why it is important to check the engine volume

Most often, the engine capacity is recognized when there is need to increase the compression ratio, that is, if there is need to bore the cylinders for the purpose of tuning. Since the greater the compression ratio, the greater the pressure on the piston during the combustion of the mixture, and, consequently, the engine will be more powerful. The technology of volume change to a greater extent, in order to increase the degree of compression, is very beneficial — after all, the portion of the fuel mixture is the same, and there is more useful work. But everything has its limits and its excessive increase threatens with spontaneous ignition, as a result of which detonation occurs, which not only reduces power, but also threatens with the motor destruction.

FAQ

• What is engine displacement measured in?

  Engine displacement is measured in cubic centimeters (cm3), but in the documentation it is often written in liters (l.). 1000 cubic centimeters is equal to 1 liter. The unit of the most accurate measurement of volume is cc centimeters, because when the volume of the car engine is specified in liters, rounding up to a whole number after the decimal point is done. For example, the volume of 2.4 liters is 2429 cm3.

• What is the formula for engine cylinder displacement?

  The working volume of an engine cylinder is equal to the product of the number Pi (3.1415) by the square of the base radius and by the height of the stroke in it of the piston. The very formula for the volume of an ICE cylinder in cubic centimeters looks like this: Vrab = π⋅r²⋅h/1000. Or by an alternative formula: V=(πD²/4)h.

• How to measure the engine volume of a car?

  The volume of an engine is the sum of the working volumes of all its cylinders, accordingly, you must first find out what the volume of one cylinder is and then multiply by their number. The volume of a cylinder is calculated by multiplying the height by the square of the radius and the number «Pi». However, to measure the working volume of the cylinder in the engine, the height should be the length of the piston stroke from the MMT to TDC, and the radius can also be measured with a ruler, having first learned the diameter of the cylinder. This method of measurement is possible only with the head removed or known parameters.

• Engine displacement 1.8L in cm3

  When converting the metric volume unit equal to 1.8 liters, then in cc it will be 1800 cm³, but if it concerns the volume of the engine, it may vary as the manufacturer, specifying the volume of 1.8, rounded off the value of what is measured in cm3. That is, it can be as 1799 as well as 1761, and even 1834. Consequently, it is possible to find out what 1.8 engine displacement is in cm³ only from the technical specification of a particular car.