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Belts / Tensioners / Rollers

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DISPLAYING 1 to 13 (of 13 products)
Special Order item
90019202750
Product Information
Product Information
Air con belt.

porsche

Fits:
Porsche 911 1969-73
Porsche 911SC 1974-83
Porsche 911 Turbo 1975-77

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Related, superseded, cross reference or alternative numbers for comparison.

90019202750
90019202750
90019201350

The product you are viewing cross references to these numbers
90019202750/1
Product Information
Product Information
Air con belt. Width: 13,0 mm, Length: 1110,0 mm.

dayco

Fits:
Porsche 911 1969-73
Porsche 911SC 1974-83
Porsche 911 Turbo 1975-77

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Related, superseded, cross reference or alternative numbers for comparison.

90019202750
90019202750
13A1110C
90019201350

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Special Order item
90019200550
Product Information
Product Information
Air Pump Belt - 9.5 x 975.

porsche

Fits:
Porsche 911 3.2L 1978-89

Click 'Zoom in' for large parts diagram.
Diagram Ref No 35.

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Related, superseded, cross reference or alternative numbers for comparison.

90019200550
90019200550
520100975

The product you are viewing cross references to these numbers
Special Order item
9991921765A
Product Information
Product Information
Alternator Belt, Narrow V-belt.
Belt size: 10 x 710

porsche

Fits:
Porsche 911 1965-73
Porsche 911 Turbo 1976 >>
Porsche 911 SC 1974-79 (Check Size of your Belt)
Porsche 911 SC 1980-83
Porsche 911 3.2L 1984-89
Porsche 914 1970-76

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Related, superseded, cross reference or alternative numbers for comparison.

9991921765A
99919217650
9991921765A

The product you are viewing cross references to these numbers
Special Order item
99919209750
Product Information
Product Information
Alternator belt, Belt size: 9.5 x 725.
The Genuine Porsche 99919209750 alternator belt is an OE V-belt for selected Porsche 911 1974–1979 models. It drives the alternator and cooling fan, helping maintain battery charging and essential air-cooled engine cooling. Ideal for routine servicing or replacing a cracked, slipping, noisy or worn original belt.

Fits:
Porsche 911 Turbo/SC 1974 - 1979 (Please choose by size)

Diagram ref no 12

This belt is used on selected classic Porsche 911 models and fits the alternator / cooling fan pulley system.

What This Part Does / Functions
•  Drives the alternator from the engine pulley system
•  Helps keep the battery charged while the engine is running
•  Drives the engine cooling fan on air-cooled Porsche 911 models
•  Supports correct engine cooling airflow
  Helps maintain stable electrical system performance
•  Provides correct OE Porsche belt fitment for the listed pulley setup
•  Replaces a worn, cracked, stretched, glazed or noisy belt
  Helps prevent belt slip, squeal and charging/cooling issues.

Why Replace This Part?
The alternator belt is a critical service item on air-cooled Porsche 911 models because it drives both the alternator and the cooling fan. Over time, the belt can crack, glaze, stretch, fray or lose grip on the pulleys. A worn or slipping belt can cause charging problems and may reduce cooling fan speed, which can lead to engine temperature concerns. Replacing the belt with a Genuine Porsche OE alternator belt helps restore correct belt drive, reliable battery charging and proper cooling fan operation.

When to Replace This Part
•   If the belt is cracked, glazed, frayed or visibly worn
•   If the belt squeals or slips during engine operation
•   If the battery or charging warning light appears
•   If the belt tension can no longer be set correctly
•   During scheduled service or preventative maintenance
•   When replacing alternator, fan pulley, shims or related belt-drive hardware
•   If the belt has been contaminated by oil, fuel or debris
•   When recommissioning a stored classic Porsche 911.

Where It Fits on the Car
This belt fits on the rear engine alternator / cooling fan pulley system. It runs between the crankshaft pulley and the fan/alternator pulley assembly, driving the alternator and cooling fan.

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

99919209750
99919209750

The product you are viewing cross references to these numbers
99919209750/2
Product Information
Product Information
Alternator belt, Belt size: 9.5 x 725.
This OE Match alternator belt is a replacement engine drive belt for Porsche 911 models from 1974 to 1979. It is designed to match the original-style fitment and function. This replacement drive belt helps power the alternator and cooling fan assembly, supporting reliable battery charging and engine cooling system operation.

Fits:
Porsche 911 Turbo/SC 1974 - 1979 (Please choose by size)

Diagram ref no 12

The alternator belt transfers rotational drive from the engine pulley to the alternator and fan assembly. This allows the alternator to generate electrical power for the vehicle while also helping drive the engine cooling fan. A correctly fitted and tensioned belt is essential for reliable charging, cooling airflow, and overall engine operation.

Functions
•   Replaces the alternator drive belt
•   Drives the alternator and cooling fan assembly
•   Supports correct battery charging
•   Helps maintain air-cooled engine cooling airflow
•   Replaces cracked, glazed, stretched, frayed, noisy, or slipping belts
•   Suitable for routine servicing and preventative maintenance
•   OE Match replacement for classic Porsche 911 engine service.

Why Replace This Part?
Alternator belts wear over time due to heat, engine vibration, pulley contact, age, and tension changes. A worn belt can crack, glaze, stretch, fray, squeal, slip, or fail completely. If the belt fails, the alternator may stop charging and the cooling fan may stop operating correctly, which can lead to warning lights, battery issues, overheating risk, or vehicle breakdown. Replacing the belt helps maintain dependable charging and cooling system performance.

When to Replace This Part
•   The alternator belt is cracked, glazed, frayed, loose, or worn
•   Belt squeal or chirping is heard during start-up or acceleration
•   The battery warning light appears
•   Charging system output is low or inconsistent
•   Cooling fan drive is being inspected or serviced
•   Alternator, fan, pulleys, or related hardware are being repaired
•   Preventative belt replacement is being carried out during scheduled maintenance.

Where it fits on the car
This belt fits on the alternator and cooling fan drive system on Porsche 911 models from 1974 to 1979. It runs between the relevant engine pulley and alternator / fan pulley according to the factory belt routing.

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

99919209750
99919209750

The product you are viewing cross references to these numbers
9991921765A/1
Product Information
Product Information
Alternator belt, Narrow V-belt.
Belt size: 10 x 713 mm
The V-belt runs between the crankshaft pulley and the alternator/fan pulley. It’s the primary mechanical link that spins the alternator to charge the battery and, on air-cooled 911s and 914-6 models, turns the engine cooling fan.

Fits:
Porsche 911 1965 - 1973
Porsche 911 Turbo 1976 >>
Porsche 911 SC 1974 - 1979 (Check Size of your Belt)
Porsche 911 SC 1980 - 1983
Porsche 911 3.2L 1984 - 1989
Porsche 914 1970 - 1976

Please note: Always confirm against the belt size currently fitted and pulley setup before ordering.

Why Replacement Matters - With age and mileage, belts:
Crack, glaze, or harden, reducing grip
 Stretch, making correct tension impossible
 Begin to slip, causing charging issues and, on air-cooled engines, reduced cooling fan speed

A slipping or failing belt can lead to battery discharge, warning lights, overheating, or being stranded. Fitting a fresh belt restores reliable alternator and fan drive, protecting both the engine and electrical system.

When to Replace - Consider replacing the alternator belt if:
  You see cracks, fraying, glazing, or missing chunks in the belt rubber
•  The belt squeals on startup or under load
•  The belt has stretched and can’t be tensioned correctly
•  You’re doing routine service on a classic 911 / 914-6 or preparing for a long trip
  The car is undergoing engine-out work or restoration

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

9991921765A
99919217650
9991921765A
520100715

The product you are viewing cross references to these numbers
99919209750/1
Product Information
Product Information
Alternator belt.
Width: 10 mm, Length: 725 mm

dayco

Fits:
Porsche 911 Turbo/SC 1974-79 (Please choose by size)

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99919209750
99919209750
052 010 0725

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Special Order item
9991923135A
Product Information
Product Information
Alternator Belt. Narrow V-Belt 9.5 x 695.

porsche

Belt size: 9.5 x 695

Fits:
Porsche 911 SC 1980-83
Porsche 911 1984-89

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

9991923135A
9991923135A

The product you are viewing cross references to these numbers
Special Order item
99919203040
Product Information
Product Information
Injection pump belt
The Genuine Porsche 99919203040 injection pump belt is an OE toothed drive belt for the mechanical fuel injection pump on selected Porsche 911 1969–1977 models. It helps maintain correct injection pump timing, stable fuel delivery and original MFI engine performance. Ideal for routine service, fuel injection system restoration or replacing an aged, worn or unknown-history belt.

Fits:
Porsche 911 1969 - 1977

Diagram ref no 21

This belt is used on Porsche 911 models equipped with a mechanical fuel injection system, where it drives the injection pump from the engine drive system.

What This Part Does / Functions
•  Drives the mechanical fuel injection pump
•  Helps maintain correct injection pump timing
•  Supports consistent fuel delivery to the engine
•  Helps ensure smooth engine running and throttle response
•  Transfers rotational drive accurately through the toothed belt profile
•  Helps prevent injection timing issues caused by belt wear or slip
•  Provides OE Porsche fitment for the original MFI pump drive system
•  Replaces an aged, cracked, stretched or worn injection pump belt.

Why Replace This Part?
The injection pump belt is a critical service item on mechanical fuel injection engines. Over time, the belt can age, crack, stretch, wear or lose tooth definition. If the belt slips, wears excessively or fails, the injection pump may lose correct timing, which can cause poor running, misfiring, difficult starting or incorrect fuel delivery. Replacing it with a Genuine Porsche OE injection pump belt helps maintain accurate MFI pump operation and supports the original performance and drivability of the classic Porsche 911 engine.

When to Replace This Part
•   During scheduled mechanical fuel injection system service
•   If the belt is cracked, worn, frayed or visibly aged
•   If injection pump timing is being reset or adjusted
•   During engine rebuild, MFI pump service or fuel system restoration
•   If the belt has been contaminated by oil, fuel or debris
•   If the belt age or service history is unknown
•   When recommissioning a stored classic Porsche 911
•   When restoring the engine with correct OE Porsche service parts.

Where It Fits on the Car
This belt fits on the engine mechanical fuel injection system, driving the mechanical injection pump. It is installed in the MFI pump drive area and works with the injection pump pulley system to maintain correct pump timing.

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

99919203040
99919203040

The product you are viewing cross references to these numbers
99919203040/1
Product Information
Product Information
Injection pump belt
The Gates injection pump belt is an OEM-quality toothed drive belt designed for Porsche 911 models equipped with the Mechanical Fuel Injection (MFI) system. Manufactured as a direct replacement for Porsche part number 99919203040, this precision-engineered belt synchronises the mechanical fuel injection pump with the engine, ensuring accurate fuel delivery and optimum engine performance.

Fits:
Porsche 911 1969 - 1977

Diagram ref no 21

A genuine Gates toothed injection pump drive belt, manufactured as a direct replacement for Porsche part number 99919203040 for MFI systems. Drives the mechanical fuel injection pump in precise synchronisation with the engine, ensuring accurate fuel metering, smooth engine operation, and consistent performance across the rev range.

Key Features & Benefits
•  Genuine Gates OEM-quality drive belt
•  Direct replacement for Porsche 99919203040
•  Precision toothed belt for MFI systems
•  High-strength reinforced construction
•  Excellent resistance to heat, wear, and stretching
•  Maintains accurate fuel injection pump timing
•  Ideal for engine rebuilds, restoration projects, and routine maintenance

Why Replacing the Injection Pump Belt
Matters The mechanical fuel injection belt is essential for maintaining precise fuel delivery. As it ages, the belt can stretch, crack, or deteriorate, affecting injection timing and engine performance. Replacing it at the recommended interval helps preserve reliable operation and protects the mechanical fuel injection system.

When to Replace the Injection Pump Belt
  During engine rebuild or cylinder head overhaul
  During mechanical fuel injection (MFI) pump servicing
  If the belt shows cracks, fraying, or worn teeth
  If oil contamination is present
  If the service history is unknown
  As part of preventative maintenance on classic MFI-equipped Porsche engines

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

99919203040
99919203040

The product you are viewing cross references to these numbers
99919203040/2
Product Information
Product Information
Injection pump belt
This OE Match injection pump belt is a replacement drive belt for the mechanical fuel injection system on Porsche 911 models from 1969 to 1977. It is designed to match the original-style fitment and function. This replacement belt helps drive the mechanical fuel injection pump, supporting correct fuel delivery and reliable engine running.

Fits:
Porsche 911 1969 - 1977

Diagram ref no 21

The injection pump belt transfers rotational drive to the fuel injection pump. This allows the pump to operate in sync with the engine and deliver fuel correctly. A good belt is essential for accurate fuel delivery, smooth running, and dependable engine performance on models using mechanical fuel injection.

Functions
•  Replaces the injection pump drive belt
•  Drives the mechanical fuel injection pump
•  Supports correct fuel delivery and engine running
•  Helps maintain injection pump timing and operation
•  Replaces cracked, worn, stretched, frayed, or missing belts
•  Suitable for fuel injection system service and preventative maintenance
•  OE Match replacement for classic Porsche 911 engine service.

Why Replace This Part?
Injection pump belts wear over time due to heat, age, tension changes, pulley contact, vibration, and engine bay conditions. A worn belt can crack, stretch, fray, slip, or fail completely. If the belt fails, the injection pump may stop operating correctly, causing poor running, loss of fuel delivery, difficult starting, or engine stoppage. Replacing the belt helps maintain reliable mechanical fuel injection performance.

When to Replace This Part
•   The injection pump belt is cracked, glazed, frayed, loose, or worn
•   Fuel injection pump service or adjustment is being carried out
•   Engine running is poor due to suspected injection pump drive issues
•   The belt tension is incorrect or unstable
•   The injection pump, pulleys, or related components are being serviced
•   Preventative belt replacement is being carried out during scheduled maintenance
•   The vehicle is undergoing Porsche 911 fuel injection or engine restoration.

Where it fits on the car
This belt fits within the mechanical fuel injection pump drive system on Porsche 911 models from 1969 to 1977. It runs around the relevant injection pump drive pulleys according to the factory engine layout.

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

99919203040
99919203040

The product you are viewing cross references to these numbers
Special Order item
9301065640Y
Product Information
Product Information

Shim washer for alternator belt pulley 0.5mm for Porsche 911 models, used to fine-tune alternator belt alignment and tension across classic 911 applications from 1965–1989.

What This Product Does
This 0.5mm shim washer sits between the alternator belt pulley halves to adjust pulley spacing, helping to achieve correct belt tension and alignment. Using the appropriate number of shims supports smooth belt operation and reduces the risk of premature belt wear.

Functions

  • Spaces the alternator pulley halves to achieve correct belt tension
  • Helps align the alternator belt with adjacent pulleys
  • Allows fine tolerance adjustment in 0.5mm steps
  • Contributes to stable alternator and cooling fan drive

Symptoms of Fault

  • Squealing or chirping from the alternator belt area on start-up or under load
  • Visible belt slack or difficulty setting correct belt tension
  • Uneven belt wear or fraying at the pulley edges
  • Traces of belt dust around the alternator and pulley
  • Intermittent charging issues linked to belt slip
  • Overheating risk on engines where the belt also drives the cooling fan

Why Replacement Matters
Alternator and fan belt systems on classic Porsche 911 models rely on a stack of correctly sized shims to set belt tension within specified tolerances. Missing, damaged, or incorrect shims can make precise adjustment difficult, leading to belt slip, noise, and accelerated wear. Replacing worn or lost shim washers when servicing the belt or pulleys helps restore proper alignment and tension control, supporting reliable charging and cooling operation on older 911 engines.

Fits

  • Porsche 911 & 912 (1965–1989)
  • Porsche 911 1974–1977 2.7L / 1976–1977 3.0 Carrera
  • Porsche 911 1975–1977 3.0L Turbo (930)
  • Porsche 911 1978–1983 3.0L SC
  • Porsche 911 1984–1986 3.2L
  • Porsche 911 1987–1989 3.2L G50

FAQs

  • Q: How many shims should be used?
    A: Follow the Porsche workshop manual for your specific model. The total number of shims is usually fixed, with the split between in-use and parked shims determining belt tension.
  • Q: Where are the spare shims stored?
    A: Typically, unused shims are kept under the pulley nut or outer pulley half so they remain available for future adjustment.
  • Q: When should shims be renewed?
    A: Replace shims that are bent, corroded, damaged, or missing when changing the alternator belt or pulley components, to ensure accurate tolerance adjustment.

Support & Advice
Ensure you use the correct combination of shims to bring the belt tension within the recommended tolerances for your engine. Always confirm fitment against your vehicle details (model, year, engine) before installation.



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

9301065640Y
93010656400
9301065640Y

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DISPLAYING 1 to 13 (of 13 products)
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About Belts / Tensioners / Rollers

Engine Rebuild Belts, Tensioners & Rollers – Precision Timing for Reliable Porsche Performance

Engine rebuild belts, tensioners, and rollers are essential components in maintaining your Porsche’s precise engine timing and smooth operation. These parts work together to synchronise the camshaft and crankshaft, ensuring valves open and close at exactly the right time for optimal combustion. Over time, these components can wear or deteriorate, especially under high performance or extended use, making replacement vital during an engine rebuild or major service.

At Design911, we supply a full range of genuine and high-quality belts, tensioners, and rollers for various Porsche models including, 911, Boxster, Cayman, Cayenne, Macan, and Panamera models. Each component is designed for strength, accuracy, and long-lasting reliability — ensuring your rebuilt Porsche engine performs flawlessly mile after mile.

What Do Engine Belts, Tensioners & Rollers Do?

These components form the heart of the engine’s timing and auxiliary systems. They:

  • Drive key engine components, including the camshaft, alternator, and water pump.
  • Maintain accurate timing for optimal combustion and efficiency.
  • Reduce friction and noise through smooth roller and tensioner operation.
  • Ensure consistent belt tension to prevent slippage or premature wear.

Together, they guarantee your Porsche’s engine runs smoothly, efficiently, and reliably — whether cruising or driving at peak performance.

Why Do Belts, Tensioners & Rollers Fail?

Exposure to high temperatures, vibration, and constant motion causes natural wear over time. Common causes of failure include:

  • Aging rubber belts becoming brittle or cracked.
  • Worn bearings in rollers or tensioners leading to noise or vibration.
  • Loss of tension causing belt slippage or timing misalignment.
  • Contamination from oil or coolant degrading materials.
  • Extended maintenance intervals leading to unexpected failure.

Symptoms of failing components include squealing noises, poor engine performance, rough idle, or even timing belt failure, which can cause severe engine damage if ignored.

Why Replace Belts, Tensioners & Rollers During an Engine Rebuild?

Replacing these components during an engine rebuild ensures long-term reliability and eliminates the risk of future timing-related failures. A fresh set of belts, rollers, and tensioners restores precision, efficiency, and performance — protecting your investment.

Benefits of replacement include:

  • Restored precise timing and smooth operation.
  • Reduced risk of catastrophic engine failure.
  • Enhanced reliability and longevity of the rebuild.
  • Quieter, more efficient engine performance.

All components available from Design911 are made using premium-grade materials, precision bearings, and advanced heat-resistant compounds, ensuring maximum durability and performance in high-stress Porsche engines.

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