How Tos / Tech

Roller Derby: How to Break In a Roller Camshaft


By now, it’s common practice (or should be) to use break-in oil with ZDDP or a zinc additive for a flat-tappet camshaft.

But what about roller cams? Any old oil will work for that, right?

According top engine builders, ring manufacturers, and cam grinders, the answer is no. And the reason is pretty simple.

While the rings need to be seated in a roller, an oil that “wears-in” the rings will create a lot of fine metal particulate, and that particulate is a killer for your roller cam. According to Timken, the number-one reason for premature roller bearing failure is particulate contamination. An engine creates more particulate wear metal during break-in than at any other time. In fact the “normal” wear metals for a new engine are up to four times higher than after a engine has finished breaking-in—hence the term “breaking-in.”

So what does this have to do with motor oil?

Quite simply, not all break-in oils are the same. Some break-in oils are designed to accelerate the break-in process, and as a result, these oils generate higher levels of wear metal—bad news for your roller bearings. Other oils are friction modified. The added slipperiness of these oils can prevent the rings from seating properly

Striking the right balance is critical.

jgr-01806_xlDriven BR break-in oil, for example, was formulated to help Joe Gibbs Racing with its engine program. Mark Cronquist, Chief Engineer Builder at Joe Gibbs Racing, says the break-in oil has two jobs: protect the valvetrain and not hinder ring seal.

“With a compacted graphite block and tool steel rings, the materials are very hard, so if the oil is too slippery, the rings won’t seat properly,” Cronquist said. “We still have a valvetrain with roller bearings that need protection as well, so the break-in oil features a high anti-wear formulation without friction modifiers to chemically assist the ring sealing. This strategy reduces the amount of wear metals created during break-in, and that protects the roller bearings in the valvetrain.”

Another aspect of roller cam break-in to consider is the high spring pressures and contact loads the cam, lifters, pushrods, and rockers see. While these loads would spell death to a flat-tappet cam, the high ZDDP anti-wear package of a break-in oil also protects these components during that critical break-in period.

Think of a break-in oil like a primer. Putting down primer before you paint establishes a uniform coating to build from, and that is exactly what a break-in oil does—it establishes a uniform anti-wear film that provides the foundation for protection. Just like a thick coat of primer smoothes out a surface, a properly formulated break-in oil does the same thing. The protective layer of ZDDP anti-wear film smoothes out the peaks and valleys that comprise the microscopic surfaces on the roller wheels and needle bearings. A smooth surface enables greater load carrying with less fatigue.

The more aggressive the valvetrain, the more critical these details become.

“It is hard to fall off the bottom of the mountain,” said Brian Reese from COMP Cams. “The more aggressive the valvetrain is in terms of lift, duration, and spring pressure, the less margin of error you have. The little details become critical.”

According to Reese, using a break-in oil is just part of the equation.

“We are seeing a trend away from flat-tappet engines to avoid the oil issues related to flat tappet cams, but just because you have a roller cam does not mean that it does not have to be broken in properly,” Reese said. “NASCAR level engine programs like Joe Gibbs Racing are still doing a 30-minute break-in on their roller cam engines because they have learned the hard way what happens when they don’t.”

Reese says improper break-in will catch up with you eventually.

“If you get the break-in wrong with a flat tappet cam, it dies right in front of your face,” he said. “If you get the break-in wrong with a roller cam, it may not die until several thousands of miles down the road, but the problem began at break-in.”

Here are a few break-in tips from the experts:

  1. CCA-153_AT_xlWash off the rust preventative coating that is on the parts prior to installation. Parts are shipped with a preventative coating, and it needs to be removed for lubricants to function at maximum efficiency.
  2. Apply a calcium-sulfonate grease instead of ZDDP before assembly. While ZDDP is critical in the break-in process, it is not the best assembly lube. After cleaning the camshaft and lifters, apply calcium-sulfonate for protection and lasting lubrication during initial start-up. Then, soak your roller lifters in break-in oil.
  3. Use a finer micron filter during break-in.
  4. Prime the pump before firing the engine. This ensures a critical supply of oil to the cam and lifters at initial start-up.
  5. Do not idle the engine. Bring the engine up to 2,500 rpm and vary the speed by a few hundred rpm for 20-30 minutes.
  6. After a 30-minute break-in, change the oil filter. At this point, you have removed all the larger particles that could cause problems and you can start upping the flow rate of your filter.
  7. Change the oil and filter after initial break-in. Most of the wear metals created by an engine occur during the first hour of operation.

By properly breaking in your roller camshaft, you’ll ensure maximum performance and long life.

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  1. Don mccraw says:


  2. is this for breaking in the just the cam or the cam in a new motor. What about doing a cam swap on a already broken in motor.

    • First off you have to clean the internal cause after a while some engine dirt/mud (thats how i call it) is everywhere in the engine depending on the maintenance done so if you put a new roller cam and compagny you still have to break in the camshaft but if there’s shit inside the engine it’ll be bad for the cam break in process. Flush the old oil change filter put a cleaning product in usually its a can like 500ml …not made to run with it its not an additive so the can + new oil + new filter run for 15-20 minutes flush oil put new oil/filter again run another 15 minutes or more and flush again ! Now you’ll be ready .Make sure oil is coming clean ….. whatever you do when modifing or changing parts in an engine …cleaning is the most important thing ….. when the internal of the engine is super duper clean now do the same as if it was a brand new engine ! In that process you will flush oil and change filter like 5-6 times depending on how meticulous you are ! So be equiped .

      Hope it helped.

      coming from a car mecanic/engine builder and aircraft mecanic !

    • OnAllCylinders says:

      In addition to the advice here, we are planning an article on roller cam swaps in the near future. Thanks for reading!

  3. Exstreamly informative. Great stuff to know. One thing I learned a long time ago is, ( espesiually) building engines, ” cleanlyness is next to godliness

  4. Great information. Thanks!

  5. Pingback: Video: How to Break-In a Hydraulic Flat-Tappet Camshaft - OnAllCylinders

  6. I called Comp Cams tech line and they told me to install the cam with any old conventional motor oil on both journals and lobes and NOT to use a flat tappet specific cam or engine assembly lube of any kind on a roller cam. They also told me NOT to soak the lifters because this would pump them up. I ended up buying the cam from Howards and their instructions also said NOT to soak their retrofit hydraulic roller lifters.

  7. Denny Katz says:

    The one thing I didn’t see in any of the info, which I believe is very important, is to pre prime the oil galleys with a drill motor and oil pump primer!
    And I’m not talking only priming till you build oil pressure! The engine needs to be primed until oil comes up every pushrod thru every rocker! It took me 2 hrs of priming, turn the engine priming turn the engine on my 582 when I assembled it! It’s a tedious job but well worth it when you know you pumped oil thru each and every pushrod, main bearing, rod bearing, cam bearing and lifter bushing or bore!

  8. Dr. Pete Barnette says:

    A lot of really good info here for the old heads and the newbies… Thanks…

  9. arthur van houtte says:

    I have already installed my hydraulic roller cam with lots of cam lube and buttoned up the bottom end.i didn’t know I had to clean off the rust preventative on the cam.should I tear it back down to remove the rust preventative?

  10. Well I restored a 68 Corvette and rebuilt the original L79 327 ABC using a comp cam and hydraulic roller lifters. Followed all of Compaq’s recommendations. Here I am after 170 miles changing the lifters due to 2 collapsed lifters. Comp would not stand behind their product. I’m replacing all the lifters with Morel. 400 dollars I should not have spend. Be aware. Soaking hydraulic lifters is a no no due to pump up. You will not be able to properly adjust preload if you do. Bad info from the comp rep.

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