Originally Posted by SSDiv6 (Post 655111)

Darren,

The biggest contributor of failures is dissimilar materials, finishes, treatments, changes on the engine oil additives/composition and break-in process.

The camshaft lobes and lifter surfaces are high load contact areas, and although they may be considered highly polished contact areas, immersed or sprayed with oil, there is still some surface asperity or roughness and the reason why many engine blocks have enclosed camshaft tunnels and many enclose the camshaft tunnel area.

Flat tappet camshafts and flat tappet hydraulic and solid lifters, also need to have a specific taper on the lobe and lifter crown. I have seen too many aftermarket camshafts and lifters that have been ground without enough taper, preventing the lifter to rotate, especially with high pressure valve springs. Many of the ceramic flat tappet lifters that I have seen,do not have any taper on the crown, therefore, you have a very high contact area that eventually will wear, causing a catastrophic failure. When you have the proper taper, the engine will require a camshaft thrust plate or stop to control its movement. Nevertheless, when you have a thrust plate or stop, you also need to have the appropriate clearance because being too tight, will also prevent the rotation of the lifter.

Material compatibility between the camshaft and lifters is also a big source of failures and also the lack of Zinc and other oil additives are also a culprit. My preference of break in oils is Maxima or Joe Gibbs.

For roller cams, I recommend the use of a Calcium Sulfonate based grease or lubricant such as Lubriplate 130-AA Multi-Purpose Calcium Type Grease. Calcium Sulfonate based grease is designed for high contact areas and I apply it to the roller camshaft lobes only.

Originally Posted by Stan Weiss (Post 655125)

My understanding is the cam lobe does have a taper. The lifter bottom has a radius to it. The size of the radius depends on how the cam lobe has been ground. I believe from the factory Ford has uses a different size radius on their lifter bottom than GM does.

Stan

Originally Posted by Larry Hill (Post 655119)

Ceramic lifters failure seems to start the snowball rolling for engine destruction. We brake the cam in on a fixture, run it on a dyno, race it with break in oil and then the ceramic lets go and it’s back to square one.

Originally Posted by SSDiv6 (Post 655129)

Ceramic materials were never intended for the dynamics and type of surface contact of a camshaft lobe and lifter crown. Ceramics are polycrystalline materials joined together, in layman terms, all ceramics are multiple crystals joined and formed together.

Although they are used in high impact applications such as ballistic armor, ceramics are brittle and have poor impact strength. When ceramics are used as ballistic armor, they are also surrounded by or encased in Kevlar material and replaced after receiving an impact.

Originally Posted by Rory McNeil (Post 655138)

Concerning cam and lifter wear issues with flat tappet cams, I was looking at my old Isky Cams catalog, and they offered some special "Hardface overlay" application on the lobes, which were meant to be used with their "Chilled Iron" flat tappet lifters. My catalog is from the 80s, so no idea if Isky still offers this stuff, but curious if anybody has any experience with these, in either a Stocker type engine, or anything else.