V-Rib Belt Crank Pulley and Tensioner Kit Upgrade. Porsche 911 3.2 Carrera  ❭  AMS905024

V-Rib Belt Crank Pulley and Tensioner Upgrade  Kit by Adapt Motorsport replaces the original V-belt arrangement while retaining the standard fan drive ratio.

Fits:

• Porsche 911 1984-1986 3.2L
• Porsche 911 1987-1989 3.2L G50

What This Product Does

This conversion uses a multi-rib belt to transfer drive to the cooling fan and alternator. The eccentric-mounted idler pulley provides controlled tension adjustment and reduces belt whip, addressing limitations that can affect the original V-belt arrangement during fast engine-speed changes, hard driving or operation with a high-current alternator.

Functions

• Transfers crankshaft rotation to the fan and alternator through a V-rib belt
• Provides precise belt-tension adjustment through the eccentric idler pulley
• Reduces belt whip during rapid changes in engine speed
• Retains the original fan drive ratio
• Provides pulley markings for base and cam timing work

Technical Details

• Precision-machined from high-grade aluminium
• Black anodised finish
• Component strength validated using finite element analysis
• Timing notches at 0, 5, 120 and 240 degrees
• Standard kit includes the V-rib crank pulley, eccentric idler pulley kit, fan pulley and fan belt
• Standard+Trigger kit adds a lightweight 36-1 crank trigger disc for a crankshaft position sensor used in EFI conversions

Symptoms Addressed

• Original V-belt being displaced during rapid engine-speed changes
• Belt slip when driving a high-current alternator
• Accelerated belt wear caused by slipping
• Excessive belt tension being used in an attempt to prevent slip
• Loss of charging voltage or cooling-fan drive following belt displacement or failure

Why Replacement Matters

A displaced or slipping fan belt can interrupt alternator and cooling-fan operation. The V-rib design increases the available belt contact area, while the adjustable idler allows tension to be set without relying on excessive belt loading that may shorten alternator-bearing life.

Kit Options

• Standard Kit: V-rib crank pulley without trigger disc, eccentric idler pulley assembly, fan pulley and fan belt.
• Standard+Trigger Kit: All Standard Kit components plus a lightweight 36-1 trigger disc for EFI crankshaft-position sensing.

FAQs

• Does this kit change the fan speed? No. The original fan drive ratio is retained.
• Is it suitable for 2.7 or 3.0 engines? No. Adapt Motorsport states that the pulleys interfere with the 2.7 and 3.0 engine consoles.
• What is the trigger option for? It adds a 36-1 crank trigger disc for a crankshaft position sensor when carrying out an EFI conversion.
• Are timing marks included? Yes. The pulleys are marked at 0, 5, 120 and 240 degrees for base and cam timing settings.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

AMS905024

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