408 hyd roller, too much spring pressure?

One spring is cheaper than a double plus a damper. Simple as that.
A BH spring has fewer resonant frequencies, but not "none". They avoid surge and bounce for less cost.
OEM engines are built to price point.

Spring life depends largely on the mass of the material involved. A smaller spring is stiffer, but can't take as much stress. Larger wire diameters can take more stress and increase stiffness. For heavy use applications, a BH would be going backwards. Multiple nested springs will always have more mass. Once a BH is made from thick enough wire, it won't fit..

BHs thus require lighter valves, and rely on their lighter retainers. Then the lobes have to be engineered along with the rockers to control the load and unload rate to prevent spikes which might exacerbate surge.

All that changes when one moves into high output builds. Bigger valves, faster ramps, higher lift - they all work against a BH design..


I agree. The OEM’s place a high priority on saving money. Which is exactly why Chrysler used short valves and short installed height springs.

Shorter valves and springs cost less money. Let’s say they saved 5 cents per valve and 2 cents per spring. Times 16. Times several millions used.

It adds up right quick. That’s why the SBC was designed with a stamped steel rocker and ball/stud mounting.

It wasn’t better but it was a damn sight cheaper than a shaft system and a forged or even cast rocker.

The vast majority of times an OE does something it’s cost related.