Porsche 911-52 Engine (1976–1977) – Specs, Problems & Compatibility Database

The Porsche 911.52 is a 2,994 cc, air‑cooled flat‑six (boxer) petrol engine produced between 1976 and 1977. It features K — Jetronic continuous mechanical fuel injection, overhead valve (OHV) layout, and dry sump lubrication. In standard form it delivered 147 kW (200 PS) at 6,300 rpm with 265 Nm of torque at 4,800 rpm, engineered for responsive performance while meeting emerging emissions mandates.

Fitted exclusively to the Porsche 911 Carrera 3.0 (G — series) for Europe…

Porsche Engine
Compliance Note:

Production years 1976–1977 meet pre‑Euro national emissions standards; formal Euro classification does not apply (KBA Germany Type Approval #15982).

Porsche 911-52 Technical Specifications

The Porsche 911.52 is a 2,994 cc flat‑six air‑cooled petrol engine engineered for the 911 Carrera 3.0 (1976–1977). It combines Bosch K-Jetronic mechanical injection with OHV architecture to deliver smooth power delivery and enhanced emissions control. Designed before formal Euro regimes, it relies on thermal efficiency and mechanical precision to meet contemporary West German type approval requirements.

ParameterValueSource
Displacement
2,994 cc
Fuel type
Petrol (Leaded, compatible with unleaded with upgrades)
Configuration
Flat‑6 (boxer), OHV, 12‑valve
Aspiration
Naturally aspirated
Bore × stroke
95.0 mm × 70.4 mm
Power output
147 kW (200 PS) @ 6,300 rpm
Torque
265 Nm @ 4,800 rpm
Fuel system
Bosch K-Jetronic continuous injection
Emissions standard
Pre‑Euro (national type approval only)
Compression ratio
8.5:1
Cooling system
Air‑cooled (fan‑driven)
Turbocharger
None
Timing system
Gear‑driven camshaft
Oil type
SAE 20W-50 mineral oil (API SF/CC)
Dry weight
135 kg

Porsche 911-52 Compatible Models

The Porsche 911.52 was used exclusively in the Porsche 911 Carrera 3.0 (G-series) with rear-engine, longitudinal mounting. Platform-specific adaptations included reinforced engine mounts and revised cooling shrouds to accommodate larger 3.0 L displacement. Early 1976 units used original magnesium alloy cases, while mid‑1976 onward adopted improved material composition per PTB‑76/03, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.

Make:
Porsche
Years:
1976–1977
Models:
911 Carrera 3.0
Variants:
Coupé, Targa
View Source
Porsche Kardex Archive Doc. K911-1976

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Common Reliability Issues - PORSCHE 911-52 Compatible Models

Field reports and technical service bulletins highlight component wear patterns under high-load operation. Adherence to manufacturer service intervals and approved fluid specifications is critical for long-term reliability.

Crankcase thermal stress cracking
Symptoms: Oil pressure drop under load, metallic debris in oil, external oil seepage near oil pickup tube.
Cause: Casting inconsistencies in early magnesium alloy cases combined with inadequate cooling under high thermal load.
Fix: Inspect case with dye penetrant; replace with later-spec or reinforced aftermarket case if cracks detected.
K-Jetronic calibration drift
Symptoms: Poor idle quality, hesitation on acceleration, black smoke, high fuel consumption.
Cause: Wear in fuel distributor control plunger or degraded warm-up regulator diaphragm alters mixture.
Fix: Recalibrate system per workshop manual; replace faulty warm-up regulator or fuel distributor as needed.
Valve seat recession on unleaded fuel
Symptoms: Loss of compression, rough idle, misfires under load, increased oil consumption.
Cause: Soft valve seats erode without lead lubrication; exacerbated by sustained high-load operation.
Fix: Install hardened valve seat inserts and sodium-filled exhaust valves per OEM guidance; use lead substitute if unmodified.
Oil leaks from case seams and seals
Symptoms: Oil residue on lower engine, drips on garage floor, dry-sump tank low despite recent fill.
Cause: Age-hardened crankcase gaskets and rear main seal; thermal cycling accelerates seal degradation.
Fix: Reseal engine with OEM gasket set; inspect case integrity before reassembly per Porsche inspection protocol.
Research Basis

Analysis derived from Porsche technical bulletins (1976–1979) and Kraftfahrt-Bundesamt (KBA) failure statistics (1977–1981). Repair procedures should follow manufacturer guidelines.

PORSCHE 911-52 FAQ Common Questions Answered

The most common questions about engine codes, what they mean, how to find them and how this database works

With proper maintenance and crankcase inspection (especially on early 1976 units), the 911.52 is robust. Valve seat recession is a risk on unleaded fuel without modifications. Regular oil changes, K-Jetronic calibration, and valve adjustments every 10,000 km are essential for longevity.

Top issues include crankcase thermal cracking (early 1976 only), K-Jetronic calibration drift, valve seat recession on unleaded fuel, and oil leaks from aged seals. These are documented in Porsche Technical Bulletins PTB-76/03 and service manuals.

Exclusively the Porsche 911 Carrera 3.0 (G-series) coupé and Targa from 1976 to 1977. These were the only 3.0 L naturally aspirated 911s before the 930 turbo variant. All are rear-engine, RWD layouts with 4- or 5-speed manual transmissions.

Yes. Common upgrades include performance cams, higher-compression pistons (up to 9.5:1), and K-Jetronic recalibration. Careful balancing and oil system upgrades are advised. Period-correct builds stay under 220 PS to preserve air-cooled thermal limits.

Typical consumption is 14–16 L/100km (20–18 mpg UK) in mixed driving due to larger displacement. Highway cruising yields ~11.5 L/100km (25 mpg UK). Short-trip driving significantly worsens economy due to thermal inefficiency in air-cooled design.

No. The 911.52 is a non-interference OHV flat-six. If timing fails (unlikely, as it uses gears), valves and pistons do not contact. However, valve train damage can still occur from loose components or excessive clearance.

Porsche specifies SAE 20W-50 mineral oil with API SF/CC rating and ZDDP anti-wear additive (≥1000 ppm). Modern synthetics may cause oil pump cavitation in dry-sump systems. Change every 10,000 km or annually, whichever comes first.

Research Resources

Comprehensive technical documentation and regulatory references

Platform Overview

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Primary Sources

EUR-Lex

EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).

GOV.UK: Vehicle Approval & V5C

UK vehicle approval processes, import rules, and MoT guidance.

DVLA: Engine Changes & MoT

Official guidance on engine swaps and inspection implications.

Vehicle Certification Agency (VCA)

UK type-approval authority for automotive products.

Regulatory Context

Regulation (EC) No 715/2007

Euro emissions framework for vehicle type approval.

Commission Regulation (EU) 2017/1151

WLTP and RDE testing procedures for emissions certification.

GOV.UK: Vehicle Approval

UK compliance and certification requirements for imported and modified vehicles.

VCA Certification Portal

Type-approval guidance and documentation.

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