What comes in a serpentine belt kit?

A quality serpentine belt kit includes brackets, pulleys, hardware and at least one serpentine belt. There are two tensioning methods. More affordable systems employ adjustable brackets instead of a tensioner to set tension -- just like the old V-belt kits. It's a great way to add the grip of a serpentine belt while maintaining old school adjustable brackets. Kits with adjustable brackets, like the SB Chevy Pulley Kit shown above, typically employ two belts.

Most serpentine belt kits feature a spring loaded tensioner combined with fixed brackets and a single belt. The spring loaded tensioner constantly adjusts tension as engine load varies and as the serpentine belt stretches with age. All modern cars utilize fixed brackets and tensioners as do all Concept One Victory Series and Driver Series serpentine belt kits.

Does a serpentine belt kit include accessory drive components?

The only way to guarantee proper belt alignment and bolt-on installation is to buy a complete system that includes the accessory drive components. These include an alternator, water pump, AC compressor and/or power steering pump in addition to the brackets and pulleys. You should also be very aware that the brand and condition of accessory drive components is critical. The rpm of drive components often exceeds engine rpm. An alternator, for example can spin up to 18,000 rpm. The pulley diameters MUST match the drive components' operating ranges and limits. So it is best to buy a complete system that includes true high performance parts from brands like Powermaster, Edelbrock, Gates, PRW and Lares.

Why is a serpentine belt better than a V-belt?

To increase grip, a serpentine belt is wider than a v-belt and has multiple ribs that further multiply surface contact. Think of each serpentine belt rib as a small v-belt that mates with a corresponding groove in a pulley. A serpentine belt also leverages the flat side of the belt to engage idler pulleys for even more belt grip.  Idlers may also serve to reverse the direction of rotation for a drive component while increasing belt wrap.

High performance serpentine belts are typically offered in 6, 8 or 10 rib widths. One example, a Concept One's Max-10R kit for a supercharged application utilizes a 10 rib belt to drive a supercharger along with an 8-rib belt to drive all accessories such as the alternator, AC compressor, and/or power steering pump. Most normally aspirated engines under 600HP can utilize a 6 rib belt.

How do I know if a serpentine belt kit will clear my chassis and radiator?

It's important to only buy a serpentine belt kit from a company that provides complete dimensions on their website. Part of a Chevy LS serpentine belt kit diagram is shown above. The full diagram for this serpentine belt kit can be seen HERE. It's also best to buy a system that is designed to tuck directly in front of the engine as best as possible.  Known as a mid-mount serpentine belt kit, this design strives to keep the AC compressor and alternator below or close to below the valve covers with the power steering pump raised up  for chassis and steering gear clearance. The compact SD-7 style AC compressor has been a game changer in accessory drive packaging design.  A tight mid-mount accessory drive system also looks racy in addition to fitting better in your chassis.

Will a serpentine belt kit handle 500-plus horsepower?

Today's high performance engines can easily make 400-500 horsepower. Proper accessory drive bracket design eliminates flexing which can lead to belt slippage as well as bracket stress cracks. Some companies use a single plate that bolts to your engine's water pump. At well under 1" thick, these single plate designs provide limited support for heavy drive components such alternators or AC compressors. It turns out these thin, single plate designs have the structural integrity of a boneless chicken. Single plate serpentine kits are not recommended for 400+ HP engines or any engine that exceeds 4500 rpm (load increases with rpm). 

Concept One Serpentine Belt Kits utilize both front and rear brackets to support all accessory drive components. This ensures that load is distributed across multiple planes. By properly cradling all accessory drive components, bracket flex is eliminated.

What else should I look for when buying a serpentine belt kit?

When buying a serpentine belt kit, choose a brand that let's you configure your system to meet your vehicle's needs and your personal preferences. Concept One offers multiple alternator amperages and three power steering reservoirs as well as many finish options such as polished, machined or anodized.

Concept One also offers it's exclusive billet mini power steering reservoir that looks ready to win a trophy at a Goodguys show, as well as pulley covers on Victory Series serpentine belt kits.

What is more important in a serpentine belt kit: looks or performance?

Both are important, but appearance will not get you home. It is possible to have your cake and eat it too.  Choose a serpentine belt kit with strong brackets, brand new, brand name accessory drive components and great looks. In our opinion a properly designed mid mount serpentine belt kit looks muscular and racy. In the case of Concept One, the system will be visually appealing as well as strong.

Links:

Chevy Pulley Systems

Ford Pulley Systems

Powermaster Alternators

Edelbrock Water Pumps

Lares Corporation

Helpful Gates Belt Tension Calculator

Goodguys Rod & Custom Association