The Porsche M 64.50 is a 3,600 cc, air‑cooled flat‑six naturally aspirated petrol engine produced between 1995 and 1998. It features Bosch Motronic M5.2 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 performance and precise throttle response.
Fitted exclusively to the Porsche 911 (993) Carrera S and select wide — body variants, the M 64…
All production years (1995–1998) meet Euro 2 standards (German KBA Type Approval #KBA/M64.50/96).
The Porsche M 64.50 is a 3,600 cc air‑cooled flat‑six naturally aspirated petrol engine engineered for high‑performance 993 variants (1995–1998). It combines DOHC architecture with Bosch Motronic M5.2 digital injection to deliver crisp high‑rpm response and linear power delivery. Designed to meet Euro 2 emissions standards, it integrates catalytic converters and precise fuel control while retaining the legendary air‑cooled simplicity of the 911 lineage.
| 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 M5.2 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 | 198 kg |
The Porsche M 64.50 was used exclusively in Porsche's 993 platform with rear‑mounted, longitudinal flat‑six layout. This engine powered the 911 Carrera S (993) and select wide-body variants from 1995 through 1998, representing the final evolution of the air‑cooled 911 engine family. Platform-specific tuning included revised cam profiles and enhanced airflow over base M64 engines. No licensed third-party applications exist. All adaptations are documented in OEM technical bulletins.
The M 64.50's primary reliability risk is camshaft lobe wear under high-RPM or cold-start conditions, with elevated incidence in track-driven or poorly maintained examples. Porsche internal service data from 1998 noted cam replacements before 80,000 km in pre-1997 builds used aggressively, while German KBA records show elevated mechanical failure notices in high-compression 993 models. Aggressive driving without warm-up increases stress, making thermal management and oil quality critical.
Analysis derived from Porsche technical bulletins (1995–1998) and German KBA failure statistics (1997–2004). Repair procedures should follow manufacturer guidelines.
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The M 64.50 is robust in well-maintained examples but has known weaknesses in early camshafts (1995–1996). Post-1997 engines feature improved hardening 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 cam lobe wear (early models), DOHC chain tensioner degradation, Motronic sensor faults, and cam cover oil leaks. These are documented in Porsche Technical Bulletin 993/95/07 and service records from the late 1990s.
Exclusively the Porsche 911 (993) Carrera S (1995–1998) and select wide-body variants. It is the DOHC, 300 PS evolution of the M64 family and the final high-output air-cooled 911 engine before the water-cooled 996 transition.
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 64.50 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 cam lobe and seal compatibility. Change every 5,000 km to protect high-RPM components.
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