Pulleys, Crank, Alternator & Water Pump for LS, Coyote, K20

What This Pulleys Collection Covers

This collection spans accessory-drive and performance pulleys, including crank, underdrive, supercharger, idler, and tensioner styles. The correct component depends on engine family, belt rib count, accessory layout, forced-induction system, diameter, offset, mounting design, and intended boost or accessory speed.

Crank and Underdrive Pulleys

Control accessory speed

Underdrive crank pulleys reduce accessory speed at high engine rpm and can reduce rotating mass on applicable engines. Confirm harmonic damping requirements before replacing a factory damper or crank pulley.

Supercharger Pulleys

Tune boost carefully

A smaller supercharger pulley can increase blower speed and boost, while a larger pulley can be used for a more conservative setup. Belt grip, belt length, fuel supply, intercooling, tuning, and engine limits all matter.

Idler and Tensioner Pulleys

Keep belts stable

Idler and tensioner pulleys route the belt and help maintain proper tension. A worn bearing, damaged flange, or misaligned pulley can cause belt noise, belt walk, and accessory-drive failure.

Belt Alignment and Rib Count

Match the full drive system

Verify pulley diameter, belt rib count, groove profile, offset, hub design, and fastener pattern. High-grip 8-rib and 10-rib supercharger combinations must be planned as a complete system.

Dampers and Engine Safety

Do not overlook torsional control

Some engines rely on a harmonic damper to control crankshaft vibration. Use an application-specific solution and follow manufacturer torque instructions when working around the crankshaft bolt.

Top Pulleys Brands

• ATI. Super damper and performance accessory-drive solutions.
• Fluidampr. Viscous harmonic dampers for performance engines.
• ZPE GripTec. High-grip supercharger pulley and hub systems.
• Innovators West. Performance balancers and drive accessories.
• Gates. Belts, tensioners, idlers, and accessory-drive service parts.
• Dayco. Drive belts and tensioner components for many applications.
• HKS. Import performance pulleys and engine hardware.
• GReddy. Japanese performance accessories and engine parts.
• ALTA. Mini Cooper performance pulleys and accessories.
• Weapon-R. Import performance engine dampers and pulleys.
• Whipple. Supercharger systems and compatible pulley components.
• Magnuson. Supercharger hardware and accessory-drive parts.
• Metco Motorsports. Supercharger pulleys and belt-drive upgrades.
• Billet Pro Shop. Machined performance pulleys and engine accessories.
• Mishimoto. Performance engine support and cooling components.

How to Choose the Correct Engine Pulley

• Confirm the exact engine, supercharger, and accessory-drive configuration
• Match pulley diameter and belt rib count to the complete system
• Verify hub, bolt pattern, bore, offset, and groove profile
• Check whether a harmonic damper function must be retained
• Measure belt routing before changing a supercharger pulley
• Plan supporting fuel, cooling, and tuning changes for added boost
• Inspect idler and tensioner bearings for noise or roughness
• Use manufacturer torque specifications for crankshaft hardware
• Check belt tracking through the entire rpm range after installation
• Reinspect belt condition and fasteners after the first heat cycle

Common Questions

What is an underdrive pulley?

An underdrive pulley changes accessory speed, often by using a different crank pulley diameter, to reduce accessory drag at high rpm on compatible engines.

Can I replace a harmonic damper with a lightweight pulley?

Only use a replacement designed for the engine. Many engines require torsional damping and should retain an appropriate harmonic damper.

Does a smaller supercharger pulley add boost?

Often yes. A smaller blower pulley can spin the supercharger faster, but supporting fuel, cooling, belt, and tuning changes may be required.

How do I choose a belt after changing pulleys?

Use the system manufacturer belt recommendation or measure the revised routing, rib count, and tensioner range.

Why does my idler pulley make noise?

A rough bearing, belt misalignment, damaged pulley surface, or worn tensioner can create accessory-drive noise.

What is pulley offset?

Offset is the position of the belt grooves relative to the mounting surface. It must match the accessory-drive alignment.

Do I need a tune for a supercharger pulley change?

A boost-changing pulley can require calibration and supporting hardware changes. Consult the supercharger and tuning provider.

What does a 10-rib setup do?

A wider 10-rib belt system increases belt contact and grip for high-demand supercharger applications.

Can I reuse the factory crank bolt?

Follow the engine or pulley manufacturer instructions. Some applications specify a new bolt or a particular torque procedure.

Should I replace the tensioner with an idler pulley?

They serve different functions. Replace the component that is worn or select upgrades that suit the complete belt-drive system.

Why Buy Pulleys from Black Ops Auto Works

Black Ops Auto Works stocks 106 Pulleys SKUs with real fitment data, competitive pricing, and support from staff who build these vehicles themselves. Products are filterable by year, make, model, trim, engine, and drivetrain to confirm the correct application before ordering.

For focused shopping, browse our Crank and Underdrive Pulleys, Crankshaft Dampers, Water Pumps, ATI, Fluidampr.