Timing Chain Tensioner 318/360

All the old Datsun "L" series inline sixes used timing chain tensioners that were preloaded with a piston and plunger assembly that was fed STRAIGHT from the main bearings and pressed against the timing chain to keep it tight. Only drawback was, as the engine aged and oil pressure dropped, they were prone to jump time. But even with a tensioner aided with oil pressure, there was little to no friction on the chain.