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- One of the key attributes of the A7TJC spark plug is its ability to deliver a robust and reliable spark. This is made possible by its platinum or iridium center electrode, which not only enhances durability but also improves ignitability. These precious metals have higher melting points and superior electrical conductivity, ensuring a longer lifespan and reduced maintenance requirements.
Silicone


Condition: New
From this kind of standard immersion testing, one would expect that bisphenol-cured VDF/HFP/TFE fluoroelastomers would not give good service life as oil seals. Similar tests with other elastomers, such as HNBR, silicone, and acrylic rubbers, show less loss of elongation. However, it is found that, in actual service, FKM shaft seals6 have much longer service life than seals of the other elastomers. In a Japanese study of FKM lip seals, rear crankshaft seals from high-mileage automobiles (70,000–280,000 mi ie, 110,000–450,000 km) were collected and examined. No serious oil leakage was found when the seals were removed from the engines. Some deposits were found around the seal lip and on the garter spring holding the lip against the shaft. No surface cracks were found on the seal lip, and only minor crazing on the crankcase side of the flexure portion of the seal in some samples. The seal compositions were not noted, but most were probably VDF/HFP/TFE elastomers with 68–69% fluorine content.
Nitrile (NBR) Oil Seals
Replacing a rocker or cam-cover gasket

oil tank gasket.
In situations where the shaft has splines or an integral gear on the end, you’ll want to take precautions. These gears and splines often have very sharp edges that are quite detrimental to the seal’s integrity. You may use an installation sleeve that will allow the seal to slide past these hazards undamaged.
Oil seals keep contaminants separate from the lubricants that keep rotating shafts and precision bearings in good working order. Oil seals are also known as rotary shaft seals, lip seals, and shaft seals.