do not press the back button…
Enter your VAT number here and click Verify:
Your details have been verified. VAT number registered to:
,
.
Your order will now be zero rated for VAT purposes. We reserve the right to verify these details after your order request has been made and reinstate VAT if required.
Your VAT details were not recognised or were invalid. Your VAT number must be matched to your Billing Country as specified above. This is currently specified as . You do not need to enter the country code part of your VAT number as this has already been selected in your billing address details above.
The VAT number checking service is currently offline. Please supply your VAT details within the comments or special instructions field below and we will apply a VAT discount after placing your order request.
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1989 3.3L Turbo (930)
- Porsche 964 (911) C2 1989-93
- Porsche 964 (911) C4 1989-93
- Porsche 964 (911) RS 3.6L 1991-93
- Porsche 964 (911) RS 3.8L 1991-93
- Porsche 964 (911) TURBO 3.3L 1991-93
- Porsche 964 (911) TURBO 3.6L 1991-93
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 996 TURBO 2000-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
Main Bearing Set – 0.25mm Oversize Inner, Standard Outer
Rebuild your Porsche engine with confidence using this OE
Match Main Bearing Set featuring 0.25mm oversize inner diameter and standard
outer diameter, manufactured to match original factory
specifications. Tthis bearing set is intended for engines with a crankshaft
that has been reground by 0.25mm on the main bearing journals, while
retaining a standard crankcase housing bore.
Fits:
- Porsche 911 1978-1983 3.0L / SC
- Porsche 911 1984-1986 3.2L
- Porsche 911 1987-1989 3.2L G50
- Porsche 911 1975-1977 3.0L Turbo (930)
- Porsche 911 1978-1989 3.3L Turbo (930)
- Porsche 964 (911) C2 1989-93
- Porsche 964 (911) C4 1989-93
- Porsche 964 (911) RS 3.6L 1991-93
- Porsche 964 (911) RS 3.8L 1991-93
- Porsche 964 (911) TURBO 3.3L 1991-93
- Porsche 964 (911) TURBO 3.6L 1991-93
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 996 TURBO 2000-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
Diagram Ref No 21
Precision-manufactured from high-quality bearing materials, these main bearings provide the oil film stability and support required to ensure smooth crankshaft rotation, reduced friction and long engine life. They are the ideal choice for professional engine builders, Porsche specialists and enthusiasts carrying out a complete engine overhaul.
What Do Main Bearings Do?
Main bearings are one of the most critical components inside every Porsche flat-six engine.
Their primary functions include:
Supporting
the crankshaft within the crankcase.
Maintaining
precise crankshaft alignment during engine operation.
Providing
a low-friction bearing surface for smooth rotation.
Maintaining
a stable oil film between the crankshaft and bearing shell.
Absorbing
combustion and rotational loads throughout the engine.
Helping
ensure correct oil pressure and long engine service life.
Correct bearing clearances are essential for maintaining engine reliability and performance.
Why Do Main Bearings Wear?
Over time, engine bearings are subjected to enormous mechanical loads and rely entirely on a consistent supply of clean engine oil.
Common causes of bearing wear include:
- High engine mileage.
- Oil contamination from debris or worn components.
- Insufficient lubrication or low oil pressure.
- Engine overheating.
- Incorrect bearing clearances during previous rebuilds.
- High-performance or competition use.
- Fatigue after repeated heat cycles.
As bearings wear, oil clearance increases, reducing oil pressure and allowing excessive crankshaft movement that can eventually damage the crankshaft and crankcase.
When Should Main Bearings Be Replaced?
Main bearings should always be inspected during engine
disassembly and replaced when:
- Carrying out a complete engine rebuild.
- The crankshaft has been reground by 0.25mm on the main journals.
- Bearing surfaces show scoring, wear or fatigue.
- Oil pressure has fallen below specification.
- Bearing material shows signs of overheating or contamination.
- Engine knock or excessive crankshaft clearance has been identified.
- Restoring a high-mileage or performance engine.
Replacing main bearings during an engine rebuild helps ensure correct oil clearances and provides a solid foundation for reliable long-term engine performance.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
96410190151
The product you are viewing cross references to these numbers
- Porsche 955 Cayenne S 4.5L V8 2003-06
- Porsche 955 Cayenne Turbo 4.5L 2003-06
- Porsche 955 Cayenne Turbo S 4.5L 2006>>
Note: Sold as SINGLE - 16 Required per engine
Fits:
Porsche 955 S / Turbo 4.5L 2003-2006
Click 'Zoom in' for large parts diagram.
Diagram Ref No 8.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
9481032100
The product you are viewing cross references to these numbers
100 Plasigauge strips per box
PLASTIGAUGE PL-A is widely used in the measurement of clearance in plain automotive bearings. Measurement of clearance in big-end bearings can be achieved without dismantling the crankshaft.
For measurements of: 0.001″ to 0.007″ (0.025mm – 0.175mm)
Suitable for use at temperatures between 0°C and 35°C
Contents:
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
PLA007
The product you are viewing cross references to these numbers
