PowerMaster - 3" Alternator Pulley

3" Alternator Pulley for Powermaster Alternators Upgrade your charging system with this 3-inch alternator pulley designed for Powermaster alternators. Increasing the pulley diameter helps slow alternator RPM at higher engine speeds—reducing heat, drag, and wear while maintaining reliable charging performance. Features: Precision-machined 3" diameter Direct fit for Powermaster alternators Slows alternator speed for improved durability at high RPM Ideal for performance and racing applications Pulley Ratio Information: Calculate pulley ratio by dividing the diameter of your crankshaft pulley by the diameter of the alternator pulley. Example: A 7.48-inch crank pulley with a 3-inch alternator pulley yields a 2.49:1 pulley ratio (7.48 ÷ 3 ≈ 2.49). This means the alternator will spin about 18,675 RPM at 7,500 engine RPM. Standard alternators are rated to 18,000 RPM (slightly exceeded in this example). Race alternators are rated to 20,000 RPM (safe). Perfect for high-revving engines where alternator overspin can become an issue, this pulley helps extend the life of your Powermaster alternator without sacrificing charging performance.