Heat shields are designed to shield the piston ring and the bearing housing from the hot gases, and stop the exhaust gas hitting the piston ring:
- Quality requirements of a heat shield vary dramatically from one turbo to another, based upon the temperature of the application and design of the heat shield;
- In some older applications, a heat shield was generally a pressed piece of stainless steel, where the material quality and dimensional accuracy was not high, relative to other parts to the turbo;
- In the more recent turbo developments for VNT/VGT’s the dimensional accuracy has increased and the temperature the components are subjected too, is much higher as a result. Some modern heat shields are produced from high temperature material similar to the turbine wheel;
- The correct use of material is essential or it will fail – if the material quality is not the right high temperature material, they will relax, hit the back of the shaft & wheel and smash to pieces;
- Melett heat shields are mainly produced to go in Melett Cores, however they are available as a replaceable service item.