The torque specifications for automobile engine cylinder head bolts are located on the Federal-Mogul Motorparts website. The search feature is available on the Specifications Lookup page under the Technical Info heading of the main page. It offers cylinder head or hub-and-wheel bearing torque parameters for various vehicles.
The Federal-Mogul cylinder head torque specification search function lists domestic and imported automobile makes and models from 1909 through 2008. The results of a search yield the steps, a diagram pattern and the exact values in foot-pounds needed for tightening cylinder head bolts.
For a 2006 Toyota Corolla CE, for example, featuring a 1.8 liter, 1,794 cubic centimeter, 79 millimeter bore engine, there are 10 cylinder head bolts that need to be adjusted in a specific order. Each bolt is tightened with a torque wrench to 36 foot-pounds, then given a single quarter turn.
Generally, cylinder head bolts attach the cylinder head to the cylinder block of an internal combustion engine. The cylinder of the engine is the shaft that the drive piston operates in, under a great deal of pressure, so the cylinder head must be tightened to the point that a tight, reliable seal is formed. Victor Reinz, a hardware manufacturer that machines cylinder head bolts, suggests replacing the bolts every time a cylinder head is reassembled.