PMO Titanium Crankshaft Pulley, 134mm — Porsche 911 & 930, 1978–1983 (PM-O330-0)

The crankshaft pulley is the last piece of rotating mass before the belt, and on an air-cooled Porsche it is also your timing reference. PMO machines this one from aerospace-grade titanium — the highest strength-to-weight ratio of any structural metal — so you shed rotating inertia at the nose of the crank without giving up any of the strength the belt drive needs.

It is a stock-configuration V-belt pulley, not a reduced-diameter racing part. Belt geometry, fan speed and alternator drive stay exactly where Porsche put them, so this is a part you can run on a street car and forget about. PMO 3D-scanned genuine steel samples and CAD'd the part from that scan, then CNC machined it with the Porsche motorsports hole pattern.

Vehicle Fitment

• Porsche 911 (including 911SC): 1978–1983
• Porsche 930: 1978–1983

PMO makes three diameters on the same design. 134mm is the late pulley. 1974–77 911, S, Carrera and Carrera 3.0 cars generally take the 131mm (PM-O332-0), and earlier 911/912/914 the 116mm (PM-O331-0). Measure the outer diameter of the pulley on your engine before ordering — it is the only reliable check, because engines get swapped.

Timing Marks

• Z1 (TDC reference)
• 5°, 30° and 35° BTDC ignition timing marks
• FE mark for MFI pump timing
• 120° valve timing marks (Z2 & Z3) for cam checks

Key Features & Benefits

• Aerospace-grade titanium — reduces rotating mass and total engine weight
• Stock configuration — no change to belt size, fan speed or charging
• 3D scanned from genuine samples, CAD designed, CNC machined
• Porsche motorsports hole pattern
• Titanium mounting bolt included, pre-applied thread-locking compound
• Limited production run

Installation

• Torque the supplied titanium bolt to 56 ft-lb dry. Do not add oil or anti-seize — the spec is a dry torque and the bolt already carries thread locker.
• Hold the crank with a proper pulley holding tool rather than jamming the flywheel.
• Re-check your ignition timing after installation against the new marks.

Technical Specifications

• Brand: PMO (Performance Machined Originals)
• Part Number: PM-O330-0
• UPC: 707924574074
• OE Reference: 930-102-028-09
• Diameter: 134mm
• Material: Aerospace-grade titanium
• Belt Type: V-belt, stock configuration
• Hardware: Titanium crank bolt included
• Torque Spec: 56 ft-lb (dry)
• Sold As: Each

Shipping Weight & Dimensions

• Shipping weight: approximately 1.3 lb
• Carton: 9 x 9 x 3 in

Frequently Asked Questions

• How do I know whether I need 116mm, 131mm or 134mm? Measure the outside diameter of the pulley currently on your engine. Model year alone is not reliable because engines get swapped. 116mm is the early/standard size, 131mm is the 1974–77 Carrera-era pulley, 134mm is 1978–83.
• Is the bolt included? Yes — PMO supplies its own titanium crank bolt with thread-locking compound already applied.
• Will this change my fan or alternator speed? No. This is a stock-diameter, stock-configuration V-belt pulley, so drive ratios are unchanged.
• Does it work with MFI? Yes. The pulley carries the FE mark used for mechanical fuel injection pump timing.
• Is this a genuine PMO part? Yes. This is PMO PM-O330-0, not a copy.
• How much weight does it actually save? PMO does not publish a figure against the steel original, and we will not invent one. The gain is in rotating mass at the crank nose, which you feel as throttle response rather than on a scale.

California Prop 65 Warning: This product can expose you to chemicals which are known to the State of California to cause cancer and reproductive harm. For more information, visit www.P65Warnings.ca.gov. Legal for use on pre-pollution-controlled vehicles only.

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PMO Parts Engine Parts & Performance Porsche 911 / 912 Porsche 930 All Porsche