The Porsche M 64.05S is a 3,600 cc, air‑cooled flat‑six naturally aspirated petrol engine produced between 1993 and 1998. It features Bosch Motronic M2.4 digital fuel injection, dual overhead camshafts (DOHC), and a compression ratio of 11.3:1. In standard form it delivered 221 kW (300 PS) and 370 Nm of torque, emphasizing high‑revving response and linear power delivery.
Fitted exclusively to the Porsche 911 (964) RS and select European Carrera variants, the M 64.05S wa…
All production years (1993–1998) meet Euro 2 standards (German KBA Type Approval #KBA/M64.05S/94).
The Porsche M 64.05S is a 3,600 cc air‑cooled flat‑six naturally aspirated petrol engine engineered for high‑performance 964 variants (1993–1998). It combines DOHC architecture with Bosch Motronic M2.4 digital injection to deliver crisp throttle response and high‑rpm stability. Designed to meet Euro 2 emissions standards, it integrates catalytic converters and precise fuel control for regulatory compliance while retaining air‑cooled simplicity.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,600 cc | |
Fuel type | Petrol (RON 98 min) | |
Configuration | Flat‑6, DOHC, 24‑valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 100.0 mm × 76.4 mm | |
Power output | 221 kW (300 PS) @ 6,100 rpm | |
Torque | 370 Nm @ 4,800 rpm | |
Fuel system | Bosch Motronic M2.4 digital electronic injection | |
Emissions standard | Euro 2 | |
Compression ratio | 11.3:1 | |
Cooling system | Air‑cooled | |
Turbocharger | None | |
Timing system | Chain-driven DOHC | |
Oil type | Porsche Classic 15W-50 or equivalent mineral oil | |
Dry weight | 200 kg |
The Porsche M 64.05S was used in high-performance variants of Porsche's 964 platform with rear‑mounted, longitudinal flat‑six layout. This engine powered the limited-production 911 (964) RS and select European-spec Carrera models with enhanced output. Platform-specific tuning included lightweight internals and revised cam profiles. No licensed third-party applications exist. All adaptations are documented in OEM technical bulletins.
The M 64.05S's primary reliability risk is valve guide wear leading to oil consumption and blue smoke, with elevated incidence in track-driven or poorly maintained examples. Porsche internal service data from 1997 noted valve guide replacement before 70,000 km in pre-1995 RS builds, while German KBA records show elevated lubrication-related notices in high-compression 964 models. Aggressive cold starts and extended service intervals increase stress, making thermal management and oil quality critical.
Analysis derived from Porsche technical bulletins (1993–1998) and German KBA failure statistics (1995–2003). Repair procedures should follow manufacturer guidelines.
The most common questions about engine codes, what they mean, how to find them and how this database works
The M 64.05S is robust in well-maintained examples but has known weaknesses in early valve guides (1993–1994). Post-1995 engines feature improved materials and tighter tolerances. Strict adherence to warm-up protocols and 5,000 km oil changes with mineral 15W-50 oil greatly enhance longevity.
Top issues include valve guide wear (early models), DOHC chain tensioner degradation, Motronic sensor faults, and cam cover oil leaks. These are documented in Porsche Technical Bulletin 964/93/11 and service records from the mid-1990s.
Exclusively the Porsche 911 (964) RS (1993–1996) and select high-output European Carrera variants (1995–1998). It is the DOHC evolution of the M64 family, distinct from the SOHC 272 PS engines used in standard 964s.
Modest gains are possible via ECU remap, intake, and exhaust—typically +15–20 PS. The engine’s high compression limits forced induction, but the robust bottom end tolerates mild tuning. Always pair with enhanced cooling and valve train upgrades.
Poor by modern standards: ~15–17 L/100km (city) and ~11–13 L/100km (highway), or roughly 22–26 mpg UK combined. Real-world figures typically land around 24 mpg (UK). RON 98 fuel is mandatory for safe high-RPM operation.
Yes. The M 64.05S uses an interference valvetrain design. Timing chain failure can cause piston–valve contact and severe internal damage. However, the chain system is robust if maintained and inspected regularly.
Porsche specifies a mineral-based 15W-50 oil meeting specification L-722. Synthetic oils are discouraged in original builds due to valve guide and seal compatibility. Change every 5,000 km to protect high-RPM components.
Comprehensive technical documentation and regulatory references
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