A status of GTE sintered silicon nitride for advanced heat engines will be presented. This will include an update of: sintering and final properties for a number of GTE silicon nitride compositions, microstructure, density, surface finish, strength, Weibull modulus, oxidation resistance, fracture toughness etc. The status of heat engine components fabricated by injection molding or isopressed/green machining and their performance will be reviewed along with correlations between the shape fabrication technique, strength, and Weibull modulus. Costs and availability will be included where possible. Future directions for increased reliability in silicon nitride structural ceramics will be summarized.