The Porsche M 64.22 is a 3,600 cc, water‑cooled flat‑six twin‑turbocharged petrol engine produced between 1995 and 1998. It featured Bosch Motronic 5.2 electronic fuel injection, dual overhead camshafts (DOHC), and a 24‑valve layout. In the 993 Turbo it delivered 300 kW (408 PS) and 540 Nm of torque, with a redline of 6,400 rpm.
Fitted exclusively to the 993-generation 911 Turbo, the M 64.22 was engineered as the pinnacle of Porsche’s air‑cooled era—though partially water‑cooled via cylinder head jackets—and the brand’s first twin‑turbo production flat‑six. Emissions compliance was achieved via twin catalytic converters, exhaust gas recirculation (EGR), and precise lambda control, meeting Euro 2 standards under EU Directive 94/12/EC.
One documented concern is heat‑related oil degradation in the twin‑turbo hot side, which can accelerate main bearing wear during aggressive or track use. This issue is referenced in Porsche Technical Bulletin 993/05/96, which recommends enhanced oil cooling and shortened service intervals in high‑load conditions.
Production years 1995–1998 meet Euro 2 emissions standards under EU Directive 94/12/EC (VCA UK Type Approval #VCA/EMS/9935).
The Porsche M 64.22 is a 3,600 cc flat‑six twin‑turbocharged petrol engine engineered for the 993 Turbo (1995–1998). It combines Bosch Motronic 5.2 engine management with twin K16 turbochargers and DOHC architecture to deliver high-performance thrust with period-correct turbo lag. Designed as the last turbocharged air-cooled engine, it balances extreme output with Euro 2 emissions compliance through water-cooled heads and twin-catalyst exhaust.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,600 cc | |
| Fuel type | Petrol (Unleaded) | |
| Configuration | Flat‑6, DOHC, 24‑valve | |
| Aspiration | Twin-turbocharged | |
| Bore × stroke | 100.0 mm × 76.4 mm | |
| Power output | 300 kW (408 PS) | |
| Torque | 540 Nm @ 4,200 rpm | |
| Fuel system | Bosch Motronic 5.2 sequential electronic injection | |
| Emissions standard | Euro 2 | |
| Compression ratio | 8.0:1 | |
| Cooling system | Air-cooled block with water-cooled cylinder heads | |
| Turbocharger | Twin K16 turbochargers (air-to-air intercooled) | |
| Timing system | Chain-driven DOHC with hydraulic tensioners | |
| Oil type | Porsche Classic 10W‑60 mineral oil (high-zinc) | |
| Dry weight | 204 kg |
The twin K16 turbos deliver dramatic mid-range thrust but with significant lag below 2,500 rpm, requiring anticipatory driving. Air-cooling demands vigilant oil monitoring—oil changes every 5,000 km or 6 months are critical to prevent main bearing wear and turbo coking under high load. Use only high-zinc mineral oil (e.g., Porsche Classic 10W-60); synthetic oils are not recommended for original flat-tappet ancillaries. The Motronic 5.2 system is sensitive to fuel pressure—ethanol-blended fuels can degrade injector seals. Twin intercooler ducts must remain sealed to prevent boost leaks and detonation. Porsche SIB 993/05/96 recommends auxiliary oil cooler for track use.
Oil Specs: Requires high-zinc mineral oil (e.g., Porsche Classic 10W-60) per Porsche SIB 993/05/96. Synthetic oils not recommended for original flat-tappet valvetrain.
Emissions: Euro 2 certification confirmed for all 1995–1998 M 64.22 engines (EU Directive 94/12/EC, VCA Type Approval #VCA/EMS/9935).
Power Ratings: Measured under DIN 70020. Output consistent across all 993 Turbo variants (Porsche PT‑1997).
Porsche Technical Information System (TIS): Docs P993‑M6422, SIB 993/05/96
EU Directive 94/12/EC on vehicle emissions
Porsche Parts Catalogue (ETK) 1998 Edition
The Porsche M 64.22 was used exclusively in Porsche's 993 Turbo platform with rear-engine, longitudinal mounting and no external licensing. This engine powered both coupé and cabriolet Turbo variants, with identical output and architecture. From 1997, minor updates included revised turbo wastegate actuators and improved oil cooler mounting, but core internals remained unchanged. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the right-side crankcase near the oil cooler—“M64/22” confirms this variant. The 993 Turbo features wide-body “whale tail” with integrated intercooler scoops and twin exhaust tips. M 64.22 is differentiated from naturally aspirated M 64.02 by twin turbochargers, dual intercooler ducts, and Motronic 5.2 ECU with boost mapping (part #0 261 200 655). Do not confuse with M 64.20 (early 1994 prototype, lower output) or 996 Turbo’s water-cooled M 96/70 engine.
The M 64.22's primary reliability risk is turbocharger and main bearing failure due to oil coking under high heat, with elevated incidence in track or hot‑climate use. Porsche internal service data from 1998 indicated over 25 % of high‑load engines required turbo or bearing service before 100,000 km, while owner surveys correlate neglected oil changes with catastrophic seizure. Extended idling and aggressive driving without cooldown cycles accelerate wear, making oil quality and thermal management critical.
Analysis derived from Porsche technical bulletins (1995–1998) and UK specialist workshop data (1998–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE M-64-22.
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