Direct injection diesel engines have a nozzle bore formed in the cylinder head for the insertion of a fuel injection nozzle. This nozzle bore is usually located between the intake and exhaust ports which are formed in the cylinder head. This region of the cylinder head is subjected to high temperature values as the gases within the combustion chamber are burned. These high temperature values, in conjunction with the small amount of material present between the nozzle bore and the intake and exhaust ports, results in the initiation and propagation of cracks due to the high stresses to which the material is subjected. Prior attempts to reduce cracking have included the use of an alloy iron having a high resistance to thermal fatigue and also the use of a small radius or chamfer which is machined about the nozzle bore. Although both of these alternatives have proved successful to a limited extent, they each do have a disadvantage. The alloy iron is very costly to use and the radius or chamfer does not lower the stress starting value far enough to satisfy the requirements of some engine manufacturers.
Now an improved load carrying assembly has been invented which reduces the initiation and propagation of thermal fatigue cracks in the deck region of a cylinder head.