Q: I have a well-maintained 1998 Toyota 4Runner Limited with 239,000 miles. The truck has been awesome, no more than normal maintenance issues. The problem is one of the lifters is knocking. I hear it ...

From the archives: The beauty of hydraulic lifters is that they self-compensate for valvetrain clearances, doing away with the need for valvetrain adjustment. To celebrate HOT ROD's 75th anniversary, ...

"Bullwinkle, that trick never works. Why don't you figure out how to make hydraulic roller lifters survive big spring pressure." "Huh?" Like Bullwinkle, hydraulic roller lifters get no respect. It ...

The engines of yesteryear were pretty simple, with tappets clackity-clacking away on cam lobes, opening valves, and making a ruckus while doing it. Mechanical lifters were adequate for valve operation ...