The Ford HY is a 3,298 cc, inline-six overhead valve (OHV) petrol engine produced between 1954 and 1980. It was part of Ford's British "Thames" engine family, designed for commercial and passenger vehicle applications. Featuring a cast-iron block and head with a carburetted fuel system, it delivered 70 bhp (52 kW) in standard tune, providing reliable low-RPM torque for freight and passenger duties.
Fitted to models such as the Ford Thames 400E, Ford Consul Classic, and Ford Zephyr, the HY engine was engineered for durability and ease of maintenance in pre-electronic automotive environments. Emissions control was minimal by modern standards, relying on basic ignition timing and carburetion, with no catalytic converter or EGR system. It met pre-regulatory emissions norms applicable in the UK and export markets.
One documented operational concern is cylinder head cracking observed in high-load commercial applications, particularly in taxi and delivery van service. This issue, referenced in Ford Service Note 578 (1963), was attributed to sustained overheating due to coolant neglect or blocked radiator cores. From 1965 onward, revised cylinder head castings with improved water jacket integrity were introduced to enhance durability.
Production years 1954–1980 predate formal EU emissions standards; compliant with UK national type approval requirements for period.
The Ford HY is a 3,298 cc inline-six OHV petrol engine developed for British-market commercial and executive vehicles (1954–1980). It utilises a carburetted fuel delivery system and distributor-based ignition to deliver smooth power delivery and mechanical reliability. Designed for pre-emissions regulatory environments, it prioritises serviceability and long-term durability under continuous load.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 3,298 cc | |
| Fuel type | Petrol | |
| Configuration | Inline-6, OHV, 12-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 85.7 mm × 95.3 mm | |
| Power output | 70 bhp (52 kW) @ 4,000 rpm | |
| Torque | 140 lb-ft (190 Nm) @ 2,000 rpm | |
| Fuel system | Single Zenith 36WWD carburettor | |
| Emissions standard | Pre-regulatory (no DPF, EGR, or catalytic converter) | |
| Compression ratio | 7.5:1 | |
| Cooling system | Water-cooled, thermosyphon (early) / pump-circulated (post-1958) | |
| Turbocharger | Not applicable | |
| Timing system | Chain-driven camshaft | |
| Oil type | SAE 20W-50 mineral oil | |
| Dry weight | 185 kg |
The naturally aspirated OHV design provides smooth torque delivery ideal for vintage commercial use but requires adherence to 6,000-mile (9,600 km) oil change intervals to maintain bearing longevity. SAE 20W-50 mineral oil is essential due to its film strength under sustained load. Extended idling or radiator blockage may lead to overheating and head cracking, especially in early castings. Fuel quality should meet basic petrol standards (BS AU 2b) to prevent carburettor deposits. Post-1965 models feature improved cylinder head water jackets per Ford Service Note 578, significantly enhancing thermal durability. Regular points adjustment and carburettor cleaning ensure consistent operation.
Oil Specs: Requires SAE 20W-50 mineral oil (Ford Workshop Manual 400E). No API certification required for period.
Emissions: No formal emissions standards applied during production (1954–1980); compliance based on UK national type approval.
Power Ratings: Measured under SAE Gross standards. Output reflects carburetted tune with 7.5:1 compression (Ford Group PT-1955).
Ford Technical Information System (TIS): Docs B3500, B3512
Ford Workshop Manual: Thames 400E (1957 Edition)
UK National Vehicle Type Approval Archive
SAE International: J272 Engine Power Measurement (Historical)
The Ford HY was used across Ford's Thames platform with longitudinal mounting and shared architecture with TVR experimental units in niche UK builds. This engine received platform-specific adaptations-reinforced crankshafts in the Thames 400E and dual exhaust manifolds in the Zephyr-and from 1965 the updated Consul Capri adopted the revised cylinder head casting, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped horizontally on the left side of the cylinder block, near the front engine mount (Ford TIS B3505). The 6th digit of the chassis number indicates engine type ('H' for HY series). Pre-1960 models have ribbed cast-iron valve covers; post-1960 units use smooth covers. Critical differentiation from smaller Thames engines: HY has a 3.3L displacement with a longer block and six main bearings. Service parts require casting date verification—cylinder heads for pre-1965 engines are not compatible with later units due to revised water jacket design per Ford Service Note 578.
The HY's primary reliability risk is cylinder head cracking in early production units, with elevated incidence in commercial taxi and delivery applications. Internal Ford service reports from 1962 indicated a notable share of pre-1965 engines requiring head replacement before 80,000 miles, while UK MOT records show increased overheating incidents in poorly maintained examples. Extended idling and radiator neglect exacerbate thermal stress, making cooling system maintenance critical.
Analysis derived from Ford technical bulletins (1955-1970) and UK MOT failure statistics (1965-1985). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about FORD HY.
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FORD Official Site
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EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
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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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