How to Break in a New Cam

Post-Lube Moves

There are several different types of engine oils, including several diesel oils, that contain higher levels of zinc and offer better protection for flat-tappet lifters and cam lobes. The choice will come down to price and performance, with the diesel and racing oils being the best choice in terms of cost versus performance.

There are several different types of engine oils, including several diesel oils, that cont

OK, you've followed all the rules and your camshaft is now broken in and makes lots of power and all is right with the world. But your job isn't over yet. First, put about 50 miles on the engine and then drain the oil and swap filters. This will get rid of the majority of the metal that ended up in the oil during break-in. If you really want to protect your flat-tappet-cammed engine, that standard API SM spec oil is not going to do the job as well as it should, since it lacks that double shot of antiwear zinc phosphate (ZDDP). While some overzealous enthusiasts are dumping a can of GM EOS in with every oil change, there is a better solution.

You may have heard several of the higher-quality diesel engine oils contain higher levels of zinc phosphate. We've listed several different brands that should be easy to find at your local auto parts store because of the increasing popularity of diesels pickups. Among these are racing oils such as Quaker State's Q Racing that offers higher levels of ZDDP as well as many other high-performance additives. If you have a question about an oil, look for an API SJ or SM rating. If the oil has either of these ratings, it probably does not offer higher levels of ZDDP. Racing oil is generally not API rated, since the oil is not intended for daily use in production engines. But for high-performance street engines, racing oils offer advantages as long as you treat the engine to frequent drain intervals.

Engine Oils Containing Higher Levels of Zinc Phosphate

Zinc Levels in Motor Oil
The following levels give you an idea of how zinc concentrations have changed over the past three years. The new for 2007 CJ-4 diesel designation will reduce zinc levels even further.

Parts List