The Vauxhall 13 S is a 1,256 cc, inline‑four naturally aspirated petrol engine produced between 1966 and 1970. It features an overhead valve (OHV) layout with a single downdraft carburettor and a compression ratio of 8.8:1, delivering 48 kW (65 PS) and 93 Nm of torque. This engine prioritised drivability and fuel economy for compact family motoring, with a robust cast‑iron block and simple mechanical valvetrain.
Fitted to the Vauxhall Viva HB (1300 S) and select export variants, the 13 S was engineered for light-duty urban and mixed driving with modest performance expectations. Emissions controls were minimal by modern standards, as the engine predates regulated exhaust standards; it complies with no formal Euro classification but meets applicable UK construction and use regulations of its era.
One documented concern is valve seat recession when operated on modern unleaded fuel without additive protection, noted in Vauxhall Lubricants Bulletin LB‑66‑03. Original exhaust valve seats lacked hardening for lead-free operation. From 1968, Vauxhall began fitting hardened valve seat inserts in new production, though retrofit kits remained optional for earlier units operated on contemporary fuel.
Vauxhall
This engine predates EU emissions regulations; compliance is governed by UK Construction and Use Regulations applicable at time of manufacture (VCA Historical Vehicle Classification).
The Vauxhall 13 S is a 1,256 cc inline‑four OHV petrol engine engineered for compact saloons (1966–1970). It combines a single carburettor induction system with a durable cast-iron architecture to deliver responsive low-end torque and economical cruising. Designed before formal emissions standards, it reflects period-typical mechanical simplicity and ease of maintenance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,256 cc | |
| Fuel type | Petrol (Unleaded compatible with additive) | |
| Configuration | Inline‑4, OHV, 8‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 73.0 mm × 75.0 mm | |
| Power output | 48 kW (65 PS) @ 5,000 rpm | |
| Torque | 93 Nm @ 2,600 rpm | |
| Fuel system | Single downdraft carburettor (Zenith 28T) | |
| Emissions standard | None (pre-regulation era) | |
| Compression ratio | 8.8:1 | |
| Cooling system | Water‑cooled, belt-driven pump | |
| Turbocharger | None | |
| Timing system | Chain-driven camshaft (front-mounted) | |
| Oil type | SAE 20W-50 mineral oil (API SB/SC) | |
| Dry weight | 122 kg |
The OHV valvetrain offers mechanical simplicity but requires valve clearance adjustment every 10,000 km due to mechanical tappets. Regular oil changes every 5,000 km using SAE 20W-50 mineral oil are essential to protect cam lobes and followers. The Zenith 28T carburettor demands periodic jet cleaning and float-level checks for stable idle. Use of modern unleaded fuel requires lead-replacement additive or hardened exhaust valve seats per Vauxhall Bulletin LB‑66‑03 to prevent recession and loss of compression.
Oil Specs: Requires SAE 20W-50 mineral oil meeting API SB/SC (Vauxhall Lubricants Bulletin LB‑66‑01). Modern synthetics not recommended.
Emissions: No emissions standard applies; engine predates EU/UK tailpipe regulations (VCA Historical Vehicle Classification).
Power Ratings: Measured under SAE J245 (gross) standards. Figures reflect period-typical testing methodology (Vauxhall PT‑1966).
Vauxhall Workshop Manual HB Series (1968)
Vauxhall Engineering Drawings E‑1305, E‑1309
UK Vehicle Certification Agency Historical Vehicle Guidance
SAE International: J245 Engine Power Test Code (1960)
The Vauxhall 13 S was used across Vauxhall's HB platform with longitudinal front-engine mounting and no external licensing. This engine received platform-specific adaptations—revised engine mounts in the Viva SL and reinforced sump baffling in estate variants—and from 1968 the facelifted HB MkII adopted hardened exhaust valve seats, creating minor interchange limits for valve train components. All adaptations are documented in OEM technical bulletins.
Locate the engine number stamped on the left-hand side of the block, just below the cylinder head flange (Vauxhall Workshop Manual HB Series). The prefix '13S' confirms the variant. Early units (1966–1967) have smooth sump pans and non-hardened valve seats; post-1968 engines feature hardened valve seat inserts (not externally visible). Critical differentiation from base 1300: 13 S uses higher-compression pistons (8.8:1 vs 8.0:1) and larger carburettor (Zenith 28T vs 26T). Intake manifolds are not interchangeable without carburettor recalibration.
The 13 S's primary reliability risk is exhaust valve seat recession when run on modern unleaded fuel without protection, with elevated incidence in high-mileage or high-temperature operation. Vauxhall internal durability logs from 1968 noted compression loss in 18% of pre-1968 engines after 80,000 km on lead-free fuel, while UK DVSA historical data links valve wear to misfire and failed compression tests in neglected examples. Infrequent oil changes and use of low-viscosity modern oils increase cam follower stress, making correct oil specification and interval adherence critical.
Analysis derived from Vauxhall technical bulletins (1966–1970) and UK DVSA historical vehicle failure statistics (1970–1980). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL 13-S.
Comprehensive technical documentation and regulatory references
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VAUXHALL 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.
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