Most everyone would like to have a new roller cam for their engines, but let’s face it, we don’t all have that kind of cash. A hydraulic or mechanical flat tappet is still a good alternative and can give years of trouble free service. By now, most guys in the hobby have heard of the reduced zinc content in most motor oil. This isn’t really that big of a deal. There are several additives out there that work well, and quite a few oils developed for older cars with more zinc in them. Let’s talk about a couple of keys to success in getting your camshaft broken in and happy.
It is critical for the lifters to spin freely in their bores. I ship lifters in a box with individual sleeves on them to avoid any nicks during shipment, as do most of the good suppliers . The key to successful cam break in is all in the prep work. Before I wash a block for final assembly, I use an old lifter to make sure it moves freely in all of the bores. (Both up and down as well as rotation) I also scrub them liberally with a brush during cleaning. Make sure that you have enough clearance when assembling the heads both retainer to guide as well as coil bind on the spring. This is important. A bind anywhere in the valvetrain is certain to cause trouble. Also make sure to check piston to valve clearance. It is smart to remove inner springs on mechanical cams. Lots of people don’t, but its an easy thing to do to insure the long life of your cam.
Inspect the lifters to make sure they don’t have any nicks or surface imperfections. Apply lube liberally to the cam lobes and the bottoms of the lifters only. I like to use either Gibbs assembly grease or ARP moly paste. Use oil on the sides of the lifters and journals of the cam. I use Brad Penn break-in oil on all of my engines. Joe Gibbs has a similar product as does Comp Cams now. When starting the engine the first time, you want a quick, clean start up. Bring the engine up to 2000-2500 RPM immediately and vary it in that range for 20 minutes. If it gets hot, shut it down. Just don’t let it go back to idle. It is wise to use a carburator that you know works well. I am a big fan of changing the oil right away to get rid of any contaminants and assembly lubes that may be floating around in the engine. After that, change your oil regularly with a good, high zinc content oil like the Brad Penn, or a good quality oil with an additive.
Wiping a cam has very little to do with the profile itself. Just like a good paint job, it’s all in the details during the prep work.