Compcams flat tappet hydraulic failure rate is unacceptable. They know there is a problem and their answer is to keep their fingers crossed and hope for the best. I really like the Compcams grinds but I would not use anything from Comp again. When a cam fails, this requires a complete teardown. Will Comp stand behind the product. Hit and miss. If they know the XE series has high fail rates, why woudn't they nitride all cams in this series. It's simple, it's about customer service and doing the right thing, not excuses. How many out there are using Comp xe series cams? Did your cam fail?