How to Determine Cylinder Head Torque Specs

Cylinder head torque specs must be accurately followed in order to obtain the optimal capability of the cylinder heads when it comes to engine combustion. These heads should be fastened correctly, otherwise, they will not function properly and will cause the car to misfire and have larger problems in the future.

Tools and Materials

  • Fasteners
  • Calculator
  • Ruler
  • Torque Wrench

Step 1: Define the Formula

The formula T = K x U x D x P must be used. T represents torque, K is a fixed variable of 1.33, U is coefficient of friction, D is the fastener’s diameter and P is the preload.

Step 2: Determine Preload

Plug in the necessary values to the formula above. To get the fastener’s diameter, simply measure it. The coefficient of friction values are 0.2 for dry or non-lubricated fasteners and 0.09 for wet. For the preload, get the ultimate strength of your fastener from the hardware store you got them from. They should be able to give you this information. Now that you have all the values, plug them into the equation.

Step 3: Calculate Torque

Once you’ve got the value in the above equation, convert this number to foot-pounds by dividing it by 12. Cylinder head torque specs are the quotient values obtained.