It's important to know the compression ratio of your engine so that you can tune it to get the most power out of it.To find the compression ratio, divide the engine's total volume.The clearance volume of the engine is calculated by the swept volume.Take your measurements very carefully to make sure you get an accurate reading.
Step 1: The bore is measured in centimeters.
Measure the cylinder bore's diameter using a bore gauge.The diameter is the width of the cylinder.You can refer back to this number later if you write it down.
Step 2: You can find the stroke by looking at it in centimeters.
The stroke is how far the cylinder travels.Measure this using a deck bridge and dial calipers if you don't have the specifications.The dial calipers should be positioned on the deck bridge.The bridge over the cylinder should be moved to the top dead center.If you want to put the piston at the bottom dead center, you need to zero out the calipers.When the depth rod is touching the piston deck, open up the calipers and read the number.
Step 3: The deck height can be determined by using centimeters.
Measure between the cylinder and the flat surface at the top of the Piston to make sure it is dead center.The clearance volume can be taken away if your piston is above deck.The clearance volume can be increased if your piston is below deck.
Step 4: Take the top volume and divide by the number of centimeters.
Look up the part number online or use the manufacturer's specifications to find the volume.Keep in mind that a dome takes away from the clearance volume, while a dish adds to it.It's a good idea to note that the centimeters are abbreviated.
Step 5: The volume of the head gasket is measured in centimeters.
You can find this information online or in the specifications.Divide the seal ring distance by 3.1416 if it's not.Square the answer and then add the gasket thickness in thousandths of inches.Take your answer and divide it by 12 to find the head gasket volume.The head gasket is 13 inches long and 0.041 inches thick.Divide 13 by 3.1416, which is 4.138.This is the number to get.If you add 0.041, which is 0.702, you get 12.87.The head gasket volume is small.
Step 6: The volume of the combustion chamber should be known.
To find this measurement, use the specifications from the manufacturer.If you need to convert from inches to centimeters, take the number and divide it by 16.
Step 7: The swept volume can be found using the formula (cylinder diameter / 2) x x stroke.
The cylinder diameter should be divided by 2.Then, divide the result by, which is 3.14.If you want to know the swept volume of the engine, you have to multiply the result by the stroke.If your cylinder diameter is 8.1 cm and your stroke is 8.9 cm, divide 8.1 by 2 to get 4.05.Square is 16.4025.If you add this by 3.14 and 51.50385, you get 8.09.The answer is 458.38cc.
Step 8: Use the formula to find the clearance volume.
Add the volume of the chamber, the top volume, gasket thickness, and deck height.If the volume of the combustion chamber is 38.6, the gasket volume is 4.5, and the deck clearance is 1.6, there is a clearance volume.
Step 9: Plug in your numbers into the formula CR.
If you know the swept volume and clearance volume, simply add those numbers to the formula and solve it.First, add the swept volume and cylinder volume together.To find the compression ratio, divide the result by the cylinder volume.Add 458.38 and 53.7 to the swept volume and you have 512.08, which is the clearance volume.You can divide 512.08 by 53.7.The compression ratio is 9.54:1.