Using a camshaft with a lift of 0.488" on stock 462 double hump heads without upgrading the springs can potentially lead to issues. Here's why:
The lift of a camshaft refers to the distance the camshaft lobe raises the valve off its seat. When you increase the lift, the valve opens further, allowing more air and fuel into the combustion chamber, which can increase horsepower and performance. However, it also puts additional stress on the valvetrain components, including the valve springs.
Stock valve springs are designed to work with the camshaft that came with the engine, which usually has a lower lift. If you install a camshaft with a higher lift without upgrading the valve springs, several problems may arise:
Coil Bind: The stock valve springs may compress completely and bind together when the lift of the camshaft exceeds their designed limit. This can cause valve float, where the valves do not close properly, leading to power loss and potential engine damage.
Valve Train Wear: The increased stress from the higher lift camshaft can accelerate wear on the valve springs, rocker arms, pushrods, and other valvetrain components. Over time, this can lead to premature failure and potential engine damage.
Valve "Bounce": The stock valve springs may not have enough tension to keep the valves seated properly at higher engine speeds, resulting in valve bounce. This can lead to a loss of power, poor engine performance, and potential valve-to-piston contact.
To ensure proper operation and prevent potential damage, it is generally recommended to upgrade the valve springs when installing a camshaft with a higher lift. Upgraded valve springs will have the necessary tension and stability to handle the increased lift and ensure proper valve control throughout the engine's RPM range.
It is essential to consult with an experienced engine builder or performance specialist who can provide specific recommendations based on your engine's specifications, intended use, and desired performance goals. They will be able to assess the compatibility of the camshaft and valve springs and recommend any necessary upgrades to ensure a reliable and efficient engine setup.