Original Porsche Part Genuine Porsche part PCG503819A

Big Bore Piston & Cylinder Set – 3.0ltr to 3.2ltr - 98mm - 10.3:1 Compression Ratio

This Mahle 3.2ltr Piston and Cylinder Set is a high-performance big bore upgrade for the Porsche 911 3.0ltr engine, increasing bore size to 98mm and capacity to approximately 3.2 litres.

Fits:

• Porsche 911 1976-1977 3.0 Carrera
• Porsche 911 1978-1983 3.0L / SC

Designed as a replacement for the well-known Max & Moritz piston and cylinder set, the kit combines genuine Mahle forged pistons with genuine Mahle ST52 steel, Nikasil-coated cylinders and a higher 10.3:1 compression ratio.

What Does This Upgrade Do?

Increasing the bore to 98mm raises the capacity of the 3.0ltr engine to approximately 3.2ltr. The additional displacement and 10.3:1 compression ratio can improve torque, throttle response and acceleration when used as part of a correctly specified engine build.

Final power gains depend on the complete engine specification, including camshafts, crankshaft, induction, exhaust and fuel system.

Forged Mahle Pistons

Mahle forged pistons provide greater and more consistent strength than conventional cast pistons, making them particularly suitable for performance engine builds.

The pistons feature deeper mirrored valve pockets, 22mm wrist pins and an offset piston pin bore. This de-axiert design helps reduce piston noise for quieter, more factory-like operation.

Mahle Nikasil-Coated Cylinders

The genuine Mahle cylinders are manufactured from ST52 steel for high strength and thermal resistance.

Their Nikasil-coated cylinder surfaces help reduce friction and wear while providing the durable running surface required for a high-performance air-cooled Porsche engine.

Matched Mahle Pistons & Cylinders

This kit uses genuine Mahle pistons matched with genuine Mahle Nikasil-coated cylinders to maintain the correct piston-to-cylinder tolerances.

Using correctly matched components is particularly important for maintaining appropriate clearances, controlling oil consumption and achieving long-term engine reliability.

Pre-Installed Piston Rings

The sealing and oil-control rings are supplied pre-installed on the pistons, simplifying preparation for engine assembly.

Piston rings and piston pins must not be modified, as modification can affect component reliability and invalidate the manufacturer's warranty.

Performance Potential

The larger 3.2ltr capacity and 10.3:1 compression ratio provide the foundation for increased horsepower and torque.

The manufacturer reports gains of 35hp or more with an appropriately specified engine build; however, this should not be considered a guaranteed increase. Actual performance depends on camshafts, crankshaft specification, induction, exhaust, fuelling and engine tuning.

For 3.0ltr 911 SC engines originally producing approximately 180–188hp, suitable fuel-system modifications may also be required to make full use of the increased engine capacity.

Key Features

• Mahle 3.2L piston and cylinder set
• 98mm big bore
• Converts compatible 3.0ltr engines to approximately 3.2ltr
• 10.3:1 compression ratio
• Replaces Max & Moritz-style piston and cylinder set
• Genuine Mahle forged pistons
• Deeper mirrored valve pockets
• Genuine Mahle ST52 steel cylinders
• Nikasil-coated cylinder bores
• Offset piston pin bore for quieter operation
• 22mm wrist pins
• Pre-installed piston rings
• Complete matched piston and cylinder set
• Includes cylinders, pistons, rings, wrist pins and clips
• Kit weight approximately 9.78kg / 21.6lb
• Made in Germany by Mahle GmbH

Mahle 98mm Big Bore Piston & Cylinder Sets for Porsche 911 SC

The Mahle 3.2ltr, 98mm big bore piston and cylinder set provides a premium solution for Porsche 911 3.0 SC engine rebuilds and performance upgrades.

Combining increased displacement with a 10.3:1 compression ratio, forged Mahle pistons and genuine Mahle Nikasil-coated cylinders, the kit is particularly suited to performance-focused air-cooled Porsche engine builds and customers looking for a modern replacement for the Max & Moritz 3.2ltr conversion.

Professional engine assembly and measurement are recommended to confirm clearances, compression, valve-to-piston clearance and compatibility with the complete engine specification.

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

10010303200

The product you are viewing cross references to these numbers

This Mahle RSR big-bore piston and cylinder set is intended for compatible Porsche 911 3.0 Carrera and 911 SC engine builds from 1976–83. Its 98mm bore works with a 70.4mm stroke to increase displacement from 3.0 litres to approximately 3.2 litres.

Fits

• Porsche 911 3.0 Carrera 1976–77
• Porsche 911 3.0L / SC 1978–83

What This Product Does

The set replaces the original pistons and cylinders during a complete engine rebuild or displacement conversion. Forged pistons are paired with Nikasil-coated ST52 steel cylinders to provide the matched running clearances required within an air-cooled flat-six engine. A 10.3:1 compression ratio and deeper valve pockets suit a correctly planned RSR-style build and provide an alternative to the established Max & Moritz configuration.

Functions

• Increases compatible 3.0L engines to approximately 3.2L
• Forms the combustion chambers and supports compression sealing
• Transfers combustion force through the connecting rods to the crankshaft
• Provides controlled piston movement and heat transfer
• Supports oil control through matched pistons, cylinders and rings

Technical Details

• Bore diameter: 98mm
• Specified stroke: 70.4mm
• Compression ratio: 10.3:1
• Forged pistons with deeper valve pockets, off-centre pin bores and 22 x 58mm wrist pins
• ST52 steel cylinders with Nikasil-coated running surfaces
• Supplied with six cylinders, pistons, fitted rings, wrist pins and retaining clips
• Approximate kit weight: 9.78kg

The off-centre piston-pin arrangement is designed to manage piston movement and operating noise. Rings are installed on the pistons before supply, helping to keep the matched assembly together during preparation. Piston rings and wrist pins must not be modified. Final measurements remain essential before assembly, including deck height, piston-to-cylinder clearance, ring condition and valve-to-piston clearance.

Symptoms of Fault

• Low or uneven compression readings
• Excessive oil consumption or blue exhaust smoke
• High crankcase pressure or pronounced blow-by
• Piston slap, knocking or other internal engine noise
• Scored, distorted or worn cylinder surfaces found during inspection
• Damaged piston crowns, skirts or ring lands
• Metallic debris discovered in the oil or filter

Why Replacement Matters

Worn pistons, rings or cylinder surfaces can prevent the combustion chamber from sealing correctly. Replacing these components as a matched set helps restore suitable clearances, compression and oil control. The engine should be inspected and measured by an experienced air-cooled Porsche engine builder, as the final specification depends on the crankshaft, camshafts, cylinder heads, induction, exhaust, fuel system and ignition settings.

FAQs

• Is this a standard-size replacement set?
  No. It uses a 98mm big bore to convert a compatible 3.0L engine to approximately 3.2L.
• Are the pistons and cylinders matched?
  Yes. The components are supplied together to maintain the intended sizing and clearances.
• What should be checked during installation?
  Confirm all critical clearances, compression requirements, cylinder-head compatibility and the complete engine specification before final assembly.
• Does the engine require a running-in period?
  Yes. Follow the engine builder's procedure for initial start-up, oil selection, ring bedding and subsequent inspection.

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

10010303204

The product you are viewing cross references to these numbers