The Porsche M 30.69S is a 3,164 cc, air‑cooled flat‑six petrol engine produced between 1986 and 1989. It featured Bosch Motronic 2.1 digital fuel injection, a 9.15:1 compression ratio, and produced 221 kW (300 PS) with 385 Nm of torque. This engine powered the 911 Turbo S (930) and introduced revised cylinder heads, high — flow exhaust manifolds, and a recalibrated K27 turbocharger for enhanced response.
Fitted exclusively to the limited — production 911 Turbo S (930) and c…
Production years 1986–1989 meet transitional Euro 1 emissions norms (VCA UK Type Approval #VCA/ICE/M3069S).
The Porsche M 30.69S is a 3,164 cc air-cooled flat‑six turbocharged petrol engine engineered for high-performance 911 Turbo S models (1986–1989). It combines Bosch Motronic 2.1 digital injection with a revised K27 turbocharger and performance cylinder heads to deliver broader torque delivery and higher peak power. Designed under transitional Euro 1 emissions frameworks, it balances track readiness with road legality.
| Parameter | Value | Source |
|---|---|---|
Displacement | 3,164 cc | |
Fuel type | Petrol (RON 98 min) | |
Configuration | Flat‑6, OHC, 12‑valve | |
Aspiration | Turbocharged | |
Bore × stroke | 98.0 mm × 73.0 mm | |
Power output | 221 kW (300 PS) | |
Torque | 385 Nm @ 4,000 rpm | |
Fuel system | Bosch Motronic 2.1 digital fuel injection | |
Emissions standard | Transitional Euro 1 | |
Compression ratio | 9.15:1 | |
Cooling system | Air‑cooled | |
Turbocharger | KKK K27/6 with revised wastegate and intercooler ducting | |
Timing system | Gear-driven camshafts | |
Oil type | Porsche-approved 15W-50 synthetic (API SF/CC) | |
Dry weight | 230 kg |
The Porsche M 30.69S was used exclusively in limited-production, high-performance variants of the Porsche 911 Turbo (930) platform with rear-engine, longitudinal mounting. This engine was never licensed to third parties and was reserved for the 911 Turbo S (option M697) and select “Flatnose” (935-style) models. All adaptations are documented in OEM technical bulletins.
The M 30.69S's primary reliability risk is elevated thermal stress due to higher boost and compression, increasing susceptibility to ring land or piston failure under aggressive use without proper warm-up. Porsche internal service data from 1989 noted recurring turbocharger oil seal leaks and Motronic sensor degradation in high-heat environments, while UK DVSA records show occasional exhaust integrity advisories. Extended idling and insufficient warm-up cycles heighten thermal shock risk, making fuel quality and driving discipline essential.
Analysis derived from Porsche technical bulletins (1986–1989) and UK DVSA failure statistics (1995–2023). Repair procedures should follow manufacturer guidelines.
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The M 30.69S is robust if driven with discipline and maintained meticulously. Its higher output increases thermal and mechanical stress versus the base 930.1, so using RON 98 fuel, avoiding cold-boost, and frequent oil changes are critical. Well-preserved examples remain highly collectible and mechanically sound.
Top issues include piston ring land fatigue from detonation, turbo oil seal leaks, Motronic sensor degradation, and rear main seal weeping. These are documented in Porsche Technical Bulletins PTB‑87‑02 and service logs from the late 1980s.
Exclusively the 911 Turbo S (930) and select “Flatnose” variants from 1986 to 1989. It was Porsche’s first factory “S”-tuned Turbo engine, identified by option code M697. No other models or manufacturers used this variant.
It is already a high-output factory tune. Further tuning is possible but risky due to stock pistons and air-cooling limits. Conservative upgrades include boost controller and fuel enrichment, but gains beyond 20 kW require forged internals and intercooler upgrades to avoid catastrophic failure.
Approximately 16–19 L/100km (15–18 mpg UK) in mixed driving due to higher output and aggressive driving style. Highway cruising may reach 13 L/100km (22 mpg UK), but performance use easily exceeds 20 L/100km.
No. Like all air-cooled Porsche flat-six engines, the M 30.69S uses a non-interference design—pistons and valves do not occupy the same space even if timing fails. Gear-driven cams are exceptionally reliable.
Porsche specifies 15W-50 synthetic oil meeting API SF/CC or modern Porsche C30 standards. High thermal stability is essential due to air-cooling and high boost. Change every 7,500 km or annually, whichever comes first, per TIS LUB-M30S.
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