Reduce Belt slip!
Operate Smoother!
Run Quieter!

MST's Excalibur Serpentine Belt System features the same reliability, consistency, and overall quality of its other Serpentine Belt Systems. The pulleys are CNC machined from 6061-T6 aircraft quality aluminum to exacting tolerances. The idler assembly is designed with a knurl resistant face and comes with a high-rpm double row bearing.

The MST system works with Alternators or Generators reducing belt slip and delivering more cooling to your engine than a standard V-belt setup. The MST Serpentine Pulley Assembly will deliver mile after mile of adjustment free performance.

Kit includes:

• Crank Pulley (with CNC-Machined Timing Marks)
• Alternator/Generator Pulley
• Idler Bracket Assembly with Bearing
• Custom Stainless Steel Crank Bolt and Alternator/Generator Nut
• 4-Rib Belt (Gate K040370)
• Mounting Hardware
• Installation Instructions

Available from CB in Black, Blue, and Red anodized finishes - Choose color from drop-down menu above. Replacement Fan Belt for your MST Serpentine Belt System - Gates K040370.

NOTES:

• Not compatible with stock fuel injection on late model beetles.
• Not recommended for use with Aluminum Engine Cases. Instead use a steel hub pulley or an aluminum Sand Seal Pulley Kit.
• Not recommended for use with engines that are intended to consistently rev above 6,500 RPM. Refer to Technical Notes (above) for further explanation.

WARNING: Fan Overspin Risk – High RPM Applications
Serpentine belt systems provide superior grip and virtually eliminate belt slippage compared to traditional V-belt setups. While this may be considered a performance upgrade, it removes a key safeguard that the original V-belt system offered — controlled slippage under high RPM.

In engines that consistently rev over 6,500 RPM, the absence of slippage can cause the cooling fan to spin excessively fast, which can lead to mechanical failure or fan explosion.

For high-revving applications, we strongly recommend using a v-belt setup with high-quality crank and alternator pulleys, a high-performance fan belt, a welded fan (CBP# 2171), and ensuring precise pulley alignment. For further assistance, please contact our sales team.