Power Pulley, Threaded, Laser Etched, 5-3/4 Diameter

OVERVIEW

When you are looking to squeeze every last bit of horsepower out of your air-cooled Volkswagen engine, the EMPI Power Pulley is one of the most effective and time-tested bolt-on modifications you can make. By reducing the diameter of the crankshaft pulley to a compact 5-3/4 inches, you effectively change the drive ratio between the crank and the generator or alternator. In a stock configuration, the cooling fan is designed to spin significantly faster than the engine to ensure maximum cooling under all conditions, but this creates a massive amount of parasitic drag as the RPMs climb. By installing this smaller diameter pulley, you slow down the fan and charging system, drastically reducing the energy required to turn them and redirecting that reclaimed power straight to your rear wheels. It is the perfect upgrade for street performance builds and weekend drag racers who want to minimize mechanical load during high-speed runs.

This EMPI 5-hole design isn''t just about raw performance gains; it is also a significant aesthetic and functional upgrade for any high-end engine bay. Crafted from high-quality aluminum and featuring precision laser-etched timing marks, this pulley provides clear, permanent degree readings that won''t fade, chip, or rub off like the painted marks found on stock steel pulleys. The high-contrast black etched numbers allow for dead-on ignition timing adjustments, ensuring your flat-four is tuned to perfection for maximum efficiency. The threaded hub design is engineered to work with your engine''s existing oil return system, utilizing the classic spiral groove to push oil back into the case where it belongs. Whether you are building a sleek Cal-Look cruiser or a dedicated competition machine, this pulley offers the durability, accuracy, and "cool factor" required by serious VW enthusiasts who rely on Appletree Auto for their performance needs.

FITMENT

This EMPI Power Pulley is designed for 12-Volt Type 1 based air-cooled engines. Detailed fitment includes:

• Volkswagen Standard Beetle: 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977
• Volkswagen Super Beetle: 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979
• Volkswagen Karmann Ghia: 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974
• Volkswagen Type 2 Bus (1600cc): 1967, 1968, 1969, 1970, 1971
• Volkswagen Thing: 1973, 1974
• Custom Applications: Dune Buggies, Sand Rails, and Trikes utilizing Type 1 1500cc or 1600cc based upright engines.

SPECS

• Brand: EMPI
• Part Number: 00-9115-0
• Diameter: 5-3/4 Inches (Smaller than stock 7-inch diameter)
• Material: High-Strength Aluminum Alloy
• Design: Classic 5-Hole Weight Reduction Pattern
• Hub Style: Threaded (Spiral Oil Return)
• Timing Marks: Precision Laser Etched with Black Fill
• Degree Range: Full 360-degree markings for precise tuning
• Finish: Machined Aluminum
• Weight: Approximately 1.0 lb

PRO TIPS

1. Account for the Change in Cooling and Charging

Because a power pulley is smaller than a stock pulley, it slows down the rotation of your cooling fan and your generator or alternator. While this frees up horsepower, it also means your engine will not cool as effectively at idle, and your charging system will have a lower output at low RPMs. We strongly recommend against using a power pulley on a daily driver that spends a lot of time sitting in heavy, stop-and-go traffic in hot climates. This modification is best suited for performance-oriented engines where the vehicle is moving at higher speeds or for drag racing applications where maximum output is the priority.

2. You Must Use a Shorter Fan Belt

One of the most common mistakes builders make when upgrading to a 5-3/4 inch power pulley is trying to reuse the stock size fan belt. Since the circumference of the crank pulley is significantly smaller, a stock belt will be far too loose, even if you remove all the shims from the top pulley. You will need to source a shorter belt (typically a 9.5x825mm or 10x825mm depending on your specific shim setup) to ensure proper tension. Always carry a spare belt in your trunk, as these non-standard sizes are rarely available at your local big-box auto parts store in an emergency.

3. Proper Installation and Sealing

When installing this threaded pulley, always inspect the crank seal area of your engine case for any burrs or debris. Even though this pulley features a threaded "screw-back" design to keep oil inside the case, it is vital that the pulley is installed with a high-quality chrome pulley bolt and a heavy-duty washer to ensure it stays torqued to the factory specification (usually 33 ft-lbs). We also suggest applying a small amount of clean engine oil to the pulley hub before sliding it onto the crankshaft to prevent any "dry start" galling against the case during the first few rotations of the engine.