The Audi KZ is a 1,797 cc inline-four petrol engine produced by Audi between 1970 and 1975. It was engineered as a durable, overhead-valve (OHV) powerplant for mainstream sedans and wagons of the era, featuring a carburetted fuel system and rear-wheel drive layout. Delivering 60 kW (82 PS) at 5,200 rpm and 135 Nm of torque, it offered reliable performance for daily transportation.
Fitted primarily to the Audi 80 (B1) and Audi 75 models, the KZ engine was designed for economical city and highway driving with minimal maintenance demands. Its simplicity contributed to long service intervals and ease of repair, making it a practical choice during a period of rising fuel economy awareness. Emissions control was limited to basic crankcase ventilation, meeting pre-regulatory European standards of the early 1970s.
One documented engineering update occurred in 1973, referenced in Audi Technical Bulletin 73-TB-045, where a revised cylinder head casting improved coolant flow and reduced instances of localized overheating. This update was implemented mid-production and can be identified by part number 033 101 373B versus earlier 033 101 373A variants. No catalytic converters or fuel injection were fitted during the KZ production run.
Production years 1970–1975 predate formal Euro emissions standards; compliance based on national type approval (VCA UK Type Approval #VCA/MS/7501).
The Audi KZ is a 1,797 cc inline-four OHV petrol engine engineered for compact sedans (1970–1975). It combines a carburetted fuel system with a cast-iron block to deliver dependable performance and ease of maintenance. Designed for pre-regulatory emissions environments, it prioritises mechanical simplicity and durability over refinement.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,797 cc | |
| Fuel type | Petrol (Unleaded RON 95) | |
| Configuration | Inline-4, OHV, 8-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 85.0 mm × 79.5 mm | |
| Power output | 60 kW (82 PS) @ 5,200 rpm | |
| Torque | 135 Nm @ 3,000 rpm | |
| Fuel system | Solex 32 PDSI carburettor | |
| Emissions standard | Pre-regulatory (basic CCV only) | |
| Compression ratio | 8.8:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Chain-driven camshaft | |
| Oil type | SAE 10W-40 mineral | |
| Dry weight | 138 kg |
The OHV design provides modest performance but excellent serviceability, with valve adjustments accessible via simple cover removal. Use of non-detergent oils or extended drain intervals beyond 10,000 km can lead to sludge accumulation and lifter wear, as noted in Audi SIB 74-05-18. Carburettor tuning requires adherence to factory jetting specifications (Solex 32 PDSI manual) to maintain fuel economy and idle stability. The chain-driven timing system is robust but should be inspected for stretch after 120,000 km. Cooling system integrity is critical—hoses and thermostat should be renewed every 5 years to prevent overheating, particularly in post-1973 cylinder head variants.
Oil Specs: Requires SAE 10W-40 mineral oil (Audi Service Manual 80-70). Detergent oils recommended for extended use.
Emissions: No formal Euro standard; meets pre-1976 national requirements (VCA Type Approval #VCA/MS/7501).
Power Ratings: Measured under DIN 70020. Output varies slightly with carburettor calibration and ambient conditions.
Audi Technical Information System (TIS): Docs A17820, A17825, SIB 73-TB-045
VCA Type Approval Database (VCA/MS/7501)
DIN 70020 - Power Measurement Standard for Road Vehicles
The Audi KZ was used across Audi's B1 platform with longitudinal mounting and shared architecture with NSU derivatives prior to full integration into the Volkswagen Group. This engine received platform-specific adaptations-shorter accessory belts in the Audi 80 LS and revised exhaust manifolds in the Audi 75-and from 1973 the updated cylinder head casting improved thermal management, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the front face of the engine block, just below the cylinder head (Audi TIS A17830). The 8th VIN digit indicates engine type ('K' for KZ series). Pre-1973 models have ribbed valve covers with chrome trim; post-1973 units use smooth cast covers. Critical differentiation from later fuel-injected engines: The KZ uses a Solex 32 PDSI carburettor with manual choke, while post-1976 models adopted Bosch K-Jetronic. Service parts require casting number verification—cylinder heads before 08/1973 (part 033 101 373A) are not fully compatible with later (033 101 373B) variants due to coolant passage revisions (Audi SIB 73-TB-045).
The KZ's primary reliability risk is cylinder head warping on early builds, with elevated incidence in vehicles with inconsistent coolant maintenance. Internal Audi field reports from 1974 indicated a measurable number of pre-1973 engines developing head gasket leaks before 90,000 km, while VCA records show cooling system neglect was a leading cause of failure in historic vehicle inspections. Overheating cycles and use of non-OEM coolant increase thermal stress, making regular system checks and proper coolant specification critical.
Analysis derived from Audi technical bulletins (1970-1975) and UK DVSA historic vehicle inspection data (1975-1985). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about AUDI KZ.
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 AUDI 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.
AUDI 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 officialAUDI 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.
