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.

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...

Valve spring pressure depends on installed height. Learn how installed height affects Ecotec seat pressure, open pressure, spring travel, coil bind and high-lift camshaft compatibility.