Keeping engines clean is actually just a by-product of the C&S complete vacuum pump package. Horsepower is increased several ways. One way is that as the crank spins in a partial vacuum, less air density means less resistance to rotation. The proper amount of vacuum will improve ring seal. C&S research indicates you can have too much. About 10” to 14” of vacuum at 7000 RPM yields the highest power gains. This agrees with tests done by Bill Jenkins. Besides losing power, “too much” vacuum consumes more power and can collapse oil pans, cause oil leaks, and suck gaskets. A two stage filtering system is employed to combat issues generated by using a pan vac system on circle track/endurance applications. The first stage is an oil/vapor separator, which mounts in the valve cover and separates oil vapor from the air charge being drawn out of the crankcase and returns it back into the engine. This first stage separator also allows water/vapor and crankcase contaminates to pass onto the second stage filter. The second stage filter allows the air charge to cool and condenses water vapor and crankcase combustion contaminates within an open cell foam filter element. This is all accomplished prior to any air charge reaching the pump so the pump is able to run basically fluid-less, which is how it was originally designed. How much power gain? That depends on the size of the motor. Commonly, small-block Chevys will pick up 20 to 22 HP, big blocks 30 HP or more. Very impressive for a bolt-on! An unusual feature is low price. Economy engines benefit more than high-dollar engines! Perhaps this is because bore preparation and ring seal is better to start with on more expensive engines. Another nice bonus is that motor oil will stay clean and clear far longer because of reduced contamination. C&S air pump kits include breather hose and a C&S-designed collection canister that can be emptied without tools. Bolts, belt, air pump, air pump pulley, either low-friction cog belt or v-belt pulley, crankshaft drive spud and matching cog belt or v-belt drive pulley comes with kit. Various mount plates and tensioners are available. Pump can be driven off water pump pulley, but care should be taken to run at half of engine speed or less. Air pump speed should never exceed 5000 RPM. To guarantee at least a full season of usage, the serially numbered C&S air pump carries a full one-year replacement guarantee. Just return the pump for a free replacement. Others claim reliability. C&S guarantees it!