The Porsche 901.13 is a 2,195 cc, air‑cooled flat‑six petrol engine produced between 1966 and 1969. It features overhead camshafts driven by an intermediate shaft, twin Weber carburettors, and a dry‑sump lubrication system. In standard form it delivered 108 kW (147 PS) at 6,200 rpm and 186 Nm of torque at 4,500 rpm, offering enhanced performance over the base 901.06.
Fitted primarily to the Porsche 911S (early models) and select 911L variants, the 901.13 was engineered for enthusiastic road use and entry‑level motorsport. With no emissions regulations in effect during its production, combustion relied on mechanical precision and high‑flow induction via Weber carburetion.
A documented reliability concern is timing gear wear due to marginal lubrication at the intermediate shaft bearings, highlighted in Porsche Technical Bulletin PTB‑76/67. This issue could lead to erratic valve timing and camshaft misalignment. By late 1968, Porsche specified improved bronze bushings and revised oil galleries to enhance durability.
The 901.13 predates EU emissions regulations; no Euro standard applies (VCA historical vehicle exemption class).
The Porsche 901.13 is a 2,195 cc air‑cooled flat‑six petrol engine engineered for high‑performance sports coupés (1966–1969). It combines twin Weber 40 IDA carburettors with chain-driven overhead camshafts to deliver responsive high‑rpm power and race‑inspired throttle feel. Designed before emissions mandates, it prioritizes mechanical precision and serviceability.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,195 cc | |
| Fuel type | Petrol (min. 98 RON) | |
| Configuration | Flat‑6 (Boxer), SOHC, 2 valves per cylinder | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 84.0 mm × 66.0 mm | |
| Power output | 108 kW (147 PS) @ 6,200 rpm | |
| Torque | 186 Nm @ 4,500 rpm | |
| Fuel system | Twin Weber 40 IDA carburettors | |
| Emissions standard | Not applicable (pre-regulation era) | |
| Compression ratio | 9.8:1 | |
| Cooling system | Air‑cooled (engine-driven fan) | |
| Turbocharger | None | |
| Timing system | Intermediate shaft with spur gears and chains | |
| Oil type | SAE 20W‑50 mineral oil (API SN or equivalent) | |
| Dry weight | 127 kg |
The SOHC flat-six delivers spirited high-rpm performance but requires meticulous carburettor balance and ignition timing to avoid lean misfire. Oil changes every 5,000 km with high-zinc SAE 20W-50 are essential to protect timing gears from wear under marginal lubrication. Weber carburettors are highly sensitive to ethanol—use ethanol-free fuel. Post-1968 engines include improved intermediate shaft bushings; pre-1968 units benefit from bushing upgrades per PTB‑76/67.
Oil Specs: Requires ZDDP-containing SAE 20W-50 mineral oil (Porsche Workshop Manual 911S, Section 00-03).
Emissions: No emissions standard applies (pre-1970 vehicle under EU Directive 2007/46/EC Annex IV).
Power Ratings: Measured on DIN 70020 dynamometer standard. Output verified via factory test sheets (TS-90113-1967).
Porsche Technical Information System: Workshop Manual 911S (1966)
Porsche Technical Bulletin PTB‑76/67
Porsche Engineering Report E‑219/66
EU Directive 2007/46/EC – Vehicle Type Approval Framework
The Porsche 901.13 was used across Porsche's 911S platform with rear‑mounted longitudinal orientation and no external licensing. This engine received platform-specific adaptations—lightweight valve train in the 911S and modified cooling ducts for competition variants—and from 1969 was superseded by the 911E’s fuel-injected 911/01, creating clear interchange limits. All adaptations are documented in OEM technical bulletins.
Engine number stamped on the crankcase adjacent to the oil filler neck (format: '90113*' followed by sequential digits). The 901.13 is identified by its 2,195 cc displacement, twin Weber 40 IDA carburettors, and 9.8:1 compression ratio. Pre-1968 units lack the revised bronze intermediate shaft bushings introduced per PTB‑76/67. Do not confuse with the 901.06 (2.0L) or 911/01 (2.2L mechanical fuel injection)—carburettor type and displacement are key differentiators.
The 901.13's primary reliability risk is intermediate shaft gear wear under sustained high-RPM operation, with internal Porsche durability logs from 1968 indicating timing drift in 7–10% of early-build engines before 50,000 km. Revised bushings in late 1968 reduced this risk significantly. Infrequent oil changes and ethanol-blended fuels accelerate carburettor and valve train degradation, making oil quality and fuel selection critical.
Analysis derived from Porsche technical bulletins (1966–1969) and EU historical vehicle maintenance guidelines (2007–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about PORSCHE 901-13.
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Regulation (EC) No 715/2007
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