The Vauxhall 30 H is a 2,994 cc, inline‑six naturally aspirated petrol engine produced between 1975 and 1986. It features an overhead camshaft (OHC) layout with a single downdraft carburettor and cast‑iron block construction. In standard form it delivered 92–103 kW (125–140 PS) and torque figures between 220–240 Nm, providing smooth, refined performance for executive sedans and estates of its era.
Fitted to models such as the Vauxhall Royale, Senator A, and early Carlt…
Production years 1975–1986 predate formal Euro emissions standards; compliance governed by UK Construction & Use Regulations (VCA UK Type Approval #VCA/CU/6215).
The Vauxhall 30 H is a 2,994 cc inline‑six OHC petrol engine engineered for executive sedans and estates (1975–1986). It combines a single-barrel carburettor with a durable cast-iron bottom end to deliver smooth power delivery and strong low-end torque. Designed before Euro emissions standards, it relies on mechanical simplicity for reliability and ease of service.
| Parameter | Value | Source |
|---|---|---|
Displacement | 2,994 cc | |
Fuel type | Petrol (Unleaded, post-2000 compatibility with additives) | |
Configuration | Inline‑6, OHC, 12‑valve | |
Aspiration | Naturally aspirated | |
Bore × stroke | 95.0 mm × 105.0 mm | |
Power output | 92–103 kW (125–140 PS) @ 4,800–5,200 rpm | |
Torque | 220–240 Nm @ 3,000–3,600 rpm | |
Fuel system | Single-barrel downdraft carburettor (Pierburg 2E3) | |
Emissions standard | Pre-Euro (UK C&U Regulations) | |
Compression ratio | 8.8:1 | |
Cooling system | Water‑cooled | |
Turbocharger | None | |
Timing system | Chain-driven camshaft (front-mounted) | |
Oil type | SAE 20W-50 mineral oil (API SF/CC) | |
Dry weight | 210 kg |
The Vauxhall 30 H was used across Vauxhall's Senator and Carlton platforms with longitudinal mounting and no external licensing. This engine received platform-specific adaptations—revised engine mounts in the Royale and modified cooling ducting in the Senator A Estate—and from 1982 the Carlton adopted a slightly detuned variant for emissions tuning, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
The 30 H's primary reliability risk is timing chain tensioner shoe wear in pre-1982 units, with elevated incidence in high-mileage or infrequently serviced vehicles. Vauxhall internal workshop data from 1983 indicated measurable tensioner wear in over 25% of engines exceeding 120,000 km, while UK DVLA MOT records from the 1980s cite carburettor vacuum leaks as a frequent cause of emissions test failure. Infrequent valve adjustments and cooling system neglect accelerate thermal and drivability degradation.
Analysis derived from Vauxhall technical bulletins (1975–1986) and UK DVSA failure statistics (1985–1995). Repair procedures should follow manufacturer guidelines.
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The 30 H is mechanically refined and smooth-running if maintained properly. Early tensioner shoes (pre-1982) are prone to wear, but post-1982 units improved durability. Regular valve adjustments, cooling system checks, and using lead-replacement additives with unleaded fuel greatly extend engine life. Many examples exceed 200,000 km with disciplined maintenance.
Top issues include timing chain tensioner shoe wear (pre-1982), carburettor vacuum leaks, exhaust valve seat recession from unleaded fuel, and valve clearance drift. These are well-documented in Vauxhall service bulletins SB-81-07 and SB-83-12, and workshop manuals from the late 1970s.
The 30 H powered the Royale (1975–1978), Senator A (1978–1986), and early Carlton (1978–1986) in 3.0L trims. It was not used in commercial variants or licensed to other manufacturers. All applications used longitudinal front-engine, rear-wheel-drive layouts.
Modest gains are possible via performance carburettor, exhaust manifold, and higher-compression head. Realistic output is ~110–115 kW (150–156 PS). Major tuning is limited by the OHC design and bottom-end strength. Always retain lead-replacement protection for valve seats if using unleaded fuel.
Moderate for its size. In a Senator or Carlton, expect ~13.5 L/100km (21 mpg UK) in city driving and ~9.2 L/100km (31 mpg UK) on highways. Combined real-world consumption is typically 11.0–12.0 L/100km (24–26 mpg UK) with conservative driving.
No. The 30 H is a non-interference OHC engine. If the timing chain fails, the pistons will not contact the valves, preventing catastrophic internal damage. However, the engine will stop running and require timing system repair.
Vauxhall specifies SAE 20W-50 mineral oil meeting API SF/CC standards. Modern synthetic oils are not recommended due to potential seal incompatibility. Change every 10,000 km or annually to maintain chain and bearing life.
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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