Dayco PBU1117SS25 Engine Harmonic Balancer

Overview of Dayco Race Performance 25% Underdrive Harmonic Balancer

The Dayco Race Performance 25% Underdrive Engine Harmonic Balancer (Part Number PBU1117SS25) is engineered for precision and durability in high-performance applications. Designed specifically for select Cadillac, Chevrolet, and Pontiac models, this harmonic balancer offers reliable crankshaft vibration dampening with a focus on race-ready performance.

• Compatible with Cadillac Caprice, Chevrolet Corvette, CTS, G8, and SS models
• Neutral counterweight balance for consistent engine operation
• Steel outer ring construction for enhanced durability
• Two integrated serpentine pulleys with 4 and 6 grooves respectively
• Includes timing marks and installation instructions
• Underdrive design reduces accessory speed by 25%
• 3 bolt hole configuration with a crank bore diameter of 1.481 inches (37.60 mm)

Detailed Product Features and Specifications

This harmonic balancer features a 1.481-inch crank bore and a 3-bolt hole pattern, ensuring a secure fit on compatible engines. The outer ring is made of steel, providing strength and resistance to wear. The overall outside diameter measures 6.930 inches (176.00 mm), with an overall width of 2.835 inches (72.00 mm). Two integrated serpentine pulleys are included: the first pulley has 4 grooves with a diameter of 6.142 inches (156.00 mm), and the second pulley has 6 grooves with a diameter of 5.512 inches (140.00 mm). This design supports accessory drive systems while reducing the speed by 25%, which can improve engine efficiency and accessory longevity.

The harmonic balancer does not include a crank trigger or exciter plate, nor does it come with hardware or a Woodruff key. However, installation instructions are provided to assist with proper setup. Timing marks are clearly indicated on the balancer to aid in accurate engine timing adjustments.

About the Race Performance 25% Underdrive Product Line

The Dayco Race Performance 25% Underdrive line is tailored for performance enthusiasts seeking to optimize engine accessory drive speeds. By reducing pulley speed by 25%, this underdrive harmonic balancer decreases parasitic drag on the engine, which can contribute to improved throttle response and reduced accessory wear. This product line is designed with race and high-performance applications in mind, offering a balance between durability and performance enhancement.

Applications and Problem Solving

• Reduces accessory drive speed to improve engine efficiency
• Minimizes crankshaft vibration for smoother engine operation
• Supports high-performance engine builds in Cadillac, Chevrolet, and Pontiac vehicles
• Helps prevent premature wear of belts and pulleys
• Facilitates accurate engine timing with integrated timing marks

Installation Notes and Tips

• Ensure compatibility with your specific vehicle model: Cadillac Caprice, Chevrolet Corvette, CTS, G8, or SS
• Use the provided installation instructions for proper fitment and torque specifications
• Verify the 3-bolt hole pattern and crank bore size (1.481 inches) before installation
• Check timing marks alignment during installation for accurate engine timing
• Hardware and Woodruff key are not included; reuse existing components or source separately

Quality Assurance and Warranty

Dayco manufactures this harmonic balancer to meet stringent quality standards, using durable steel materials and precise engineering. Installation instructions are included to ensure proper setup. Warranty details are subject to Dayco's standard policies; please consult the manufacturer or authorized distributor for specific warranty information related to part number PBU1117SS25.