Tailor pump shot to individual engines.
Includes 8 pump cams to fine-tune your Holley carb's accelerator pump shot. This accelerator pump cam assortment will allow you to "tailor" and fine tune your carburetor for your engine's actual requirements. Each cam has a different shape or profile to give different results. Cam "lift" directly affects the accelerator pump stroke and, therefore, pump capacity. Ramp profile or shape controls the "timing" of the shot. A steeply-rising ramp shape will give a fast, heavy fuel shot right off idle. Conversely, a gently sloping ramp will spread the pump action over a longer period of time.