Beware of Premature Camshaft Failure From Using the Wrong Diesel Oil for Breaking in Gas Engines
Some engine builders like to use API CJ-4 diesel motor oil as a break-in lubricant for new engines. That’s because it contains plenty of zinc (ZDDP) to protect flat-tappet camshafts. Apparently this oil is being replaced with a new formulation, API CK-4 and CK-4/SN (SN means the oil meets current year API standards). And just




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