The Vauxhall 28 HC is a 2,792 cc, inline‑six naturally aspirated petrol engine produced between 1987 and 1993. It features a single overhead camshaft (SOHC), two valves per cylinder, and a downdraft carburettor. Output ranges from 110–125 kW (150–170 PS) with torque between 220–240 Nm, delivering smooth linear power and refined cruising character typical of larger CIH (Cam In Head) inline‑six layouts.
Fitted to executive models such as the Senator B and Omega A, the 28 HC was engineered for drivers prioritising torque, refinement, and relaxed motorway performance over sportiness. Emissions compliance was achieved through a lean‑burn carburettor, secondary air injection, and a three‑way catalytic converter, allowing adherence to Euro 1 standards in all production years under UK VCA type approval.
One documented concern is premature wear of the camshaft lobes due to marginal oil pressure at high engine speeds. This issue, referenced in Vauxhall Engineering Bulletin EB‑91‑02, stems from the narrow oil gallery feeding the cam journals in early castings. From 1990 onward, revised camshaft metallurgy and improved oil pump relief valve settings were introduced to enhance durability.
All production years (1987–1993) meet Euro 1 standards (VCA UK Type Approval #VCA/EMS/5685).
The Vauxhall 28 HC is a 2,792 cc inline‑six naturally aspirated petrol engine engineered for executive sedans (1987–1993). It combines a single overhead camshaft with a downdraft carburettor to deliver smooth low-to-mid range torque and refined daily drivability. Designed to meet Euro 1 emissions standards, it balances mechanical simplicity with regulatory compliance through precise carburetion and catalytic aftertreatment.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 2,792 cc | |
| Fuel type | Petrol | |
| Configuration | Inline‑6, SOHC, 12‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 95.0 mm × 87.0 mm | |
| Power output | 110–125 kW (150–170 PS) | |
| Torque | 220–240 Nm @ 3,200–3,800 rpm | |
| Fuel system | Single-barrel downdraft carburettor (Weber or Zenith) | |
| Emissions standard | Euro 1 | |
| Compression ratio | 9.0:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven camshaft | |
| Oil type | SAE 10W‑40 (mineral or semi‑synthetic) | |
| Dry weight | 148 kg |
The SOHC inline‑six layout provides smooth, vibration‑free power ideal for relaxed cruising but requires valve clearance checks every 20,000 km due to mechanical tappets. Ethanol‑free fuel is recommended to prevent carburettor corrosion. Early camshafts (pre‑1990) are prone to lobe wear under sustained high-RPM use—avoid prolonged engine speeds above 5,000 rpm; replacement with post‑1990 hardened units per Engineering Bulletin EB‑91‑02 is advised during rebuilds. Use of correct oil maintains cam, chain, and distributor longevity.
Oil Specs: Requires SAE 10W‑40 mineral or semi-synthetic oil (Vauxhall Owner’s Handbook 1988). ACEA A2 compliance sufficient.
Emissions: Euro 1 certification applies to all 1987–1993 models (VCA Type Approval #VCA/EMS/5685).
Power Ratings: Measured under DIN 70020 standards. Output varies by carburettor calibration and market (Vauxhall TIS Doc. V8828).
Vauxhall Technical Information System (TIS): Docs V8828, V8837, EB‑91‑02
VCA Type Approval Database (VCA/EMS/5685)
DIN 70020 Engine Power Measurement Standard
The Vauxhall 28 HC was used across Vauxhall's Senator B and Omega A platforms with longitudinal mounting and no external licensing. This engine received platform-specific adaptations—reinforced engine mounts in the Senator and modified intake manifolds in the Omega—and from 1990 the updated camshaft design improved durability, creating minor interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front face of the cylinder block near the timing cover (Vauxhall TIS V8828). The code '28HC' is cast into the block and may be accompanied by a production date stamp. Pre-1990 units have smooth cam lobes; post-1990 versions feature visibly hardened lobe surfaces. Carburettor type (Weber 36/38 TLDM or Zenith 36/38 INAT) varies by model year but does not affect engine code. All 28 HC blocks share the same bellhousing pattern as other CIH inline‑six engines.
The 28 HC's primary reliability risk is camshaft lobe wear in pre‑1990 builds, with elevated incidence in vehicles used for frequent motorway cruising or hill climbing. Vauxhall internal service data from 1992 noted valve train noise in ~15% of early 28 HC engines before 100,000 km, while UK DVSA MOT records link misfires and compression loss to this wear pattern. Extended oil change intervals and poor-quality oil accelerate degradation, making cam integrity and oil maintenance critical.
Analysis derived from Vauxhall technical bulletins (1987–1993) and UK DVSA failure statistics (1995–2005). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL 28-HC.
Comprehensive technical documentation and regulatory references
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VAUXHALL Official Site
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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
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VCA Certification Portal
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