Engines with solid roller cams are usually performance, race engines. They use aggressive Lobe Profiles and usually run at high rpm. Because of this, they require the highest spring pressure of all the engine types.
Seat Pressure Guidelines
Seat pressure is determined by valve/retainer weight, rpm range, and desired life expectancy of the valvetrain.
The table below gives some seat pressure guidelines:
| Camshaft Type | Seat Pressure |
|---|---|
| Mild Performance | 165 lbs. minimum |
| Moderate Performance | 180 - 200 lbs. |
| High Performance/Circle Track | 220 - 250 lbs. |
| Professional Drag Racing | 340 - 370 lbs. |
Open Pressure Guidelines
Open Pressure should be the minimum pressure needed to control the valve as the lifter goes over the Nose of the Cam Lobe. Too much open pressure puts a lot of stress on other valvetrain parts. This can lead to Valve Float and broken pieces.
The only way to really find the right open pressure is through experimentation and track testing.
This table lists some starting points for your open pressure tests:
| Engine Usage | Open Pressure |
|---|---|
| Street/Strip Performance | 340 - 350 lbs. |
| Circle Track, Bracket Racing | 450 - 600 lbs. |
| Pro Level Drag Racing, Short Distance Circle Track | 600 lbs. or more |
Notes
Most manufacturers recommend valve springs to go with each cam they make. We recommend using these springs, or a spring with similar specifications.