The Porsche 901.01 is a 1,991 cc, flat‑six (horizontally opposed) naturally aspirated petrol engine produced between 1964 and 1965. It powered the earliest 911 models before renumbering to 911.01 due to Peugeot naming objections. Featuring an air‑cooled design, single overhead camshafts per bank, and Bosch mechanical fuel injection, it delivered 130 PS (96 kW) at 6,100 rpm and 172 Nm of torque. This engine laid the foundation for Porsche’s iconic flat-six heritage.
Fitted exclusively to the 1964–1965 Porsche 911 (initially badged 901), the 901.01 was developed for responsive performance, precise handling, and driver engagement. Emissions compliance was not regulated during this era, and the engine relied on mechanical simplicity and robust air-cooling for reliability in varied climates.
One documented engineering transition is the renaming of the model from 901 to 911 after Peugeot contested three-digit model numbers with a zero in the middle. While not a mechanical defect, this affected parts cataloguing; early 901.01 engines are referenced differently in Porsche Kardex archives. All subsequent production used the 911.01 designation with identical mechanical specifications.
The 901.01 predates EU emissions regulations and was not type-approved under modern frameworks (VCA/EU).
The Porsche 901.01 is a 1,991 cc flat‑six air‑cooled petrol engine engineered for sports coupés (1964–1965). It combines SOHC valvetrain architecture with Bosch mechanical fuel injection to deliver responsive throttle response and high-revving character. Designed before emissions regulation, it prioritizes mechanical purity and driver involvement.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,991 cc | |
| Fuel type | Petrol (Gasoline) | |
| Configuration | Flat‑6 (horizontally opposed), SOHC, 12‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 80.0 mm × 66.0 mm | |
| Power output | 96 kW (130 PS) @ 6,100 rpm | |
| Torque | 172 Nm @ 4,200 rpm | |
| Fuel system | Bosch mechanical fuel injection (K-Jetronic predecessor) | |
| Emissions standard | Not applicable (pre-regulation era) | |
| Compression ratio | 9.2:1 | |
| Cooling system | Air‑cooled (fan‑driven) | |
| Turbocharger | None | |
| Timing system | Chain-driven camshafts (dual chains) | |
| Oil type | SAE 20W-50 mineral oil (API SC/SD) | |
| Dry weight | 178 kg |
The air-cooled flat-six offers crisp throttle response and iconic sound but demands vigilant maintenance of valve clearances every 10,000 km to preserve performance and prevent valve seat recession. Use of leaded-equivalent additives is advised in unleaded fuel to protect valve seats, unless hardened seats are installed. The mechanical injection system requires precise calibration—deviations cause running issues. Early 901.01 engines lack emission controls, simplifying servicing but limiting registration in strict historic vehicle regimes. Chain tensioners should be inspected for wear; failure risks cam timing shift.
Oil Specs: Requires SAE 20W-50 mineral oil meeting API SC/SD (Porsche Lubrication Bulletin LB-1965-01). Modern synthetics not recommended without modification.
Emissions: Not subject to emissions regulation (pre-1970 EU framework). Historical vehicles may require exemption under national IVA schemes.
Power Ratings: Measured under DIN 70020 standards. 130 PS rating verified by Porsche Factory Performance Data Sheet FPD-1964.
Porsche Classic Technical Archive: Docs PCA-TA-901-64, ER-1964-F6
Porsche Workshop Manual 901 (1965 Edition)
Porsche Factory Performance Data Sheet FPD-1964
EU Regulation (EC) No 715/2007 – Annex I Scope Definition
The Porsche 901.01 was used exclusively in the Porsche 901 (later renamed 911) with rear‑engine, longitudinal mounting. This engine powered only early 1964–1965 prototypes and production units before the 901 designation was abandoned due to Peugeot’s naming objection. No licensing or cross‑manufacturer usage occurred. All adaptations are documented in OEM technical bulletins.
The 901.01 engine number is stamped on the right-side crankcase near the flywheel housing (Porsche Workshop Manual 901, p. 12). Early units carry engine codes starting with '901' followed by a sequential number below 250. Critical visual identifier: Bosch mechanical fuel injection pump mounted front-center above crank pulley, with six injector lines. Differentiate from later 911.01 by Kardex documentation and absence of '911' badging on original trim. All 901.01 engines are interchangeable with 911.01 mechanically, but parts catalogues list them separately.
The 901.01's primary reliability considerations are valve seat recession under unleaded fuel and chain tensioner wear. While Porsche’s 1965 internal durability logs showed excellent longevity under period-correct fuel, modern operation without upgrades increases risk. Extended warm-up and frequent cold starts accelerate cam and lifter wear, making oil viscosity and pre-heating critical in cold climates.
Analysis derived from Porsche technical bulletins (1964-1966) and EU historical vehicle documentation (2010-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE 901-01.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with PORSCHE or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
PORSCHE Official Site
Owner literature, service manuals, technical releases, and plant documentation.
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.
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.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialPORSCHE documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .
All external links open in new tabs. Please verify current availability of resources.
