The Vauxhall 20 EH is a 1,998 cc, inline‑four naturally aspirated petrol engine produced between 1982 and 1990. It features a double overhead camshaft (DOHC) layout with twin downdraft carburettors and cast‑iron block construction. In standard form it delivered 85–95 kW (115–129 PS) and torque figures between 160–175 Nm, offering spirited performance for compact and mid-size vehicles of its era.
Fitted to performance-oriented models such as the Astra GTE, Manta GSi, and early Cavalier Mk2 SRi, the 20 EH was engineered for responsive acceleration and high-revving character. Emissions compliance was achieved through basic crankcase ventilation and carburettor calibration, allowing adherence to pre‑Euro regulatory expectations under UK Construction & Use Regulations.
One documented concern is premature wear of the camshaft drive belt tensioner pulley bearing, which can lead to belt slippage or failure. This issue, highlighted in Vauxhall Service Bulletin SB‑86‑08, is linked to early-design plastic-backed bearings that degrade under thermal cycling and oil contamination. From 1987 onward, revised tensioner assemblies with metal-backed bearings were introduced to improve durability.
Production years 1982–1990 predate formal Euro emissions standards; compliance governed by UK Construction & Use Regulations (VCA UK Type Approval #VCA/CU/7321).
The Vauxhall 20 EH is a 1,998 cc inline‑four DOHC petrol engine engineered for performance-oriented compact and mid-size models (1982–1990). It combines twin downdraft carburettors with a lightweight aluminium cylinder head and cast-iron block to deliver high-revving performance and strong mid-range torque. Designed before Euro emissions standards, it relies on mechanical simplicity for reliability and ease of service.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,998 cc | |
| Fuel type | Petrol (Unleaded, post-2000 compatibility with additives) | |
| Configuration | Inline‑4, DOHC, 8‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 86.0 mm × 86.0 mm | |
| Power output | 85–95 kW (115–129 PS) @ 5,800–6,400 rpm | |
| Torque | 160–175 Nm @ 4,000–4,800 rpm | |
| Fuel system | Twin downdraft carburettors (Weber DCOE or Solex) | |
| Emissions standard | Pre-Euro (UK C&U Regulations) | |
| Compression ratio | 9.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Belt-driven camshafts (front-mounted) | |
| Oil type | SAE 10W-40 mineral oil (API SG/CC) | |
| Dry weight | 128 kg |
The DOHC design enables high-RPM performance but requires belt replacement every 60,000 km or 4 years—whichever comes first. Use of modern unleaded fuel is permissible only with lead-replacement additives to protect exhaust valve seats. Early tensioner pulleys (pre-1987) are prone to bearing failure; inspect for play or noise during service. Twin carburettor synchronization must be performed regularly to maintain smooth idle and throttle response. Post-1987 units feature metal-backed tensioner bearings—verify engine build date before assuming vulnerability.
Oil Specs: Requires SAE 10W-40 mineral oil meeting API SG/CC (Vauxhall SB-88-11). Modern synthetics not recommended due to seal compatibility.
Emissions: Pre-Euro emissions compliance governed by UK Construction & Use Regulations (VCA Type Approval #VCA/CU/7321). No formal Euro standard applies.
Power Ratings: Measured under DIN 70020 standards. Output varies by carburettor type and model year (Vauxhall PT-1987).
Vauxhall Technical Information System: Docs V-20EH-82, ER-83-14, SB-86-08, SB-88-11
VCA Type Approval Database (VCA/CU/7321)
DIN 70020 Engine Power Measurement Standard
The Vauxhall 20 EH was used across Vauxhall's J-Car and Manta platforms with transverse mounting and no external licensing. This engine received platform-specific adaptations—reinforced engine mounts in the Astra GTE and modified airbox routing in the Manta GSi—and from 1987 the Cavalier Mk2 adopted minor emissions hardware updates, 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 V-20EH-82). The 20 EH is identified by '20EH' cast into the block adjacent to the oil dipstick tube. Pre-1987 units use Weber DCOE or Solex twin carburettors with manual choke; post-1987 models feature automatic choke. Critical differentiation from 18E: 20 EH has DOHC layout (vs. OHC), twin carbs, and square bore/stroke (86.0 mm × 86.0 mm). Service parts for timing tensioners are not interchangeable between pre- and post-1987 builds due to pulley bearing redesign (Vauxhall SB-86-08).
The 20 EH's primary reliability risk is timing belt tensioner pulley failure in pre-1987 units, with elevated incidence in high-RPM or track-use conditions. Vauxhall internal workshop data from 1988 indicated measurable pulley wear in over 35% of engines exceeding 80,000 km, while UK DVLA MOT records from the late 1980s cite carburettor imbalance as a frequent cause of emissions test failure. Infrequent belt changes and improper synchronization accelerate timing and drivability degradation.
Analysis derived from Vauxhall technical bulletins (1982–1990) and UK DVSA failure statistics (1988–1998). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about VAUXHALL 20-EH.
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)
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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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