Engine Building

Does your Ecotec need cylinder-head modifications for upgraded valve springs? Learn the difference between drop-in and modified spring systems and when machining, retainers, seals, or spring-seat changes are actually necessary.

Does a performance Ecotec really need dual valve springs? Learn how single and dual springs compare in pressure, spring rate, lift, dynamic control, installation and high-RPM performance.

Camshaft duration and maximum lift do not tell the whole story. Learn how aggressive Ecotec cam lobes increase valve acceleration, spring demand and high-RPM valvetrain requirements.

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.

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.