"Hi-Intensity" hydraulic lifters produce a "variable duration effect". At lower rpm this can reduce running duration by 6 to 10 degrees and decrease valve lift by .020 to .030 in. Hi Intensity "fast bleed" lifters work best with a cam that requires more compression ratio than the engine actually has. They help restore vacuum, cylinder pressure, and bottom-end performance. As rpm increases, Hi Intensity lifters act more like normal hydraulic lifters. At 2500 to 3000 rpm they will produce the full duration and lift of the cam.
Use only if the engine's compression ratio is below the minimum recommended on the application page for the cam you have chosen. Hi Intensity lifters can cause "low speed detonation" if compression is too high. Slightly more noisy than standard lifters (NOT as noisy as a mechanical cam) and can trigger knock sensors.
- Application: Oldsmobile V8 260 - 455
- Diameter: .842"
- Seat Height: 1.655"
- Quantity: 16