Engine Building

More camshaft lift increases Ecotec valve spring compression and open pressure while reducing mechanical clearance. Learn how lift affects coil bind, retainer-to-seal clearance and spring selection.

Matching Ecotec valve springs to camshafts requires more than comparing maximum lift. Learn how cam profile, RPM, spring pressure, spring rate, valvetrain mass and mechanical clearance determine the correct combination.

Valve float, valve bounce and spring surge are different forms of Ecotec valvetrain instability. Learn what each means, how they interact, and why hydraulic lash instability should be diagnosed separately.

Higher RPM gives an Ecotec valvetrain less time to complete each valve event. Learn how engine speed increases spring demand and why RPM must be matched with camshaft profile, valve...

What causes valve float in a GM Ecotec? Learn how RPM, camshaft acceleration, valve spring pressure, spring rate, valvetrain mass and hydraulic lash-adjuster behavior affect high-RPM valve and rocker control.

Coil bind isn't the only limit on Ecotec valve lift. Learn how retainer-to-seal clearance, valve guide clearance, spring seats and retainers determine the usable lift of a performance Ecotec cylinder...