- The term shorty refers to the shorter than standard length of these plugs. This compact size is not just an arbitrary design choice; it is a response to the ever-evolving needs of modern engine bays, which are becoming increasingly cramped as vehicles integrate more technology in less space. By reducing the length of the spark plug, manufacturers can free up precious millimeters, allowing for better access, easier maintenance, and, importantly, the accommodation of other essential components.
- When choosing a Half Moon Valve Cover Gasket, quality is paramount
Figure 5: JTEKT seal numbering system
Table 6: Codes and numbers used in seal numbers
Cassette seals are designed to maximise grease or oil retention and protection against liquid or solid contaminants. These seals are provided with their own bushings in which dirt is kept out and oil/grease kept in by a multi-lip seal.
The square shape of the gasket allows for a more precise fit in square or rectangular openings, ensuring a tight seal to prevent fluids or gases from escaping. Made from high-quality rubber materials such as neoprene, silicone, or EPDM, these gaskets offer excellent resistance to temperature, pressure, and chemical exposure.
Other important factors are ensuring the hardness and roughness of the shaft are correct. A shaft hardness of HRC 45 is recommended for a rubber sealing lip, with a roughness of Ra 0.4-0.8. A higher shaft hardness of HRC 60 and shaft roughness of Ra 0.1-0.4 is recommended for a PTFE lip.
Today, traditional oil seals have to compete with a new variant oil seal, which is used in most modern engines.