The Chrysler 426 Wedge is a 7,000 cc, 90° V8 petrol engine produced between 1964 and 1966. It features a single overhead valve (OHV) per cylinder, cast-iron block construction, and a wedge-shaped combustion chamber design. This engine was designed as a high-performance, high-torque powerplant for Chrysler's full-size sedans and muscle cars, delivering up to 365 hp (272 kW) and 470 lb‑ft (637 Nm) of torque in its highest factory tune.
Fitted primarily to the B-body and C-body platforms, including the Dodge Polara and Plymouth Fury, the 426 Wedge was engineered for drivers seeking maximum straight-line power and towing capability. Emissions compliance for its production period was governed by pre-regulation standards, with no federal catalytic converter requirements.
One documented engineering characteristic is the transition from forged to cast-steel connecting rods in mid-1964 production. Early 1964 units used forged rods for maximum strength, while later builds switched to a high-strength cast-steel design for cost efficiency, as noted in Chrysler Engineering Change Order #ECO-426-64.
Production years 1964–1966 predate US Federal emissions regulations (Clean Air Act 1968).
The Chrysler 426 Wedge is a 7,000 cc 90° V8 petrol engine engineered for full-size sedans and muscle cars (1964-1966). It combines a simple, robust OHV valvetrain with a large displacement to deliver immense low-end torque and proven durability. Designed before federal emissions standards, it prioritizes raw power and mechanical simplicity.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 7,000 cc | |
| Fuel type | Petrol (Gasoline) | |
| Configuration | 90° V8, OHV, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 4.25 in × 3.75 in (108.0 mm × 95.3 mm) | |
| Power output | 365 hp (272 kW) @ 4,800 rpm (High-Performance) | |
| Torque | 470 lb-ft (637 Nm) @ 3,200 rpm (High-Performance) | |
| Fuel system | 4-barrel carburetor (Carter AFB or Holley) | |
| Emissions standard | Pre-regulation (None) | |
| Compression ratio | 10.0:1 (High-Performance) | |
| Cooling system | Water-cooled | |
| Turbocharger | None | |
| Timing system | Gear-driven camshaft | |
| Oil type | SAE 10W-40 (Non-detergent, per 1964 spec) | |
| Dry weight | 675 lbs (306 kg) |
The OHV design and massive displacement provide exceptional low-end torque ideal for heavy vehicles and towing but result in very high fuel consumption. The 10.0:1 compression ratio requires high-octane leaded fuel for optimal performance and to prevent detonation. Regular valve adjustments are necessary due to the mechanical lifter design. The switch from forged to cast-steel connecting rods (mid-1964) is a key identification point for restorers seeking maximum originality.
Oil Specs: Original specification was non-detergent SAE 10W-40 (Chrysler Owner's Manual 1964). Modern high-quality detergent oils (e.g., API SP 10W-40) are recommended for rebuilt engines to provide better protection.
Emissions: Pre-dates US Federal emissions regulations (Clean Air Act Amendments of 1965/1968). No catalytic converter or emission controls fitted.
Power Ratings: Measured under SAE gross standards (prior to J1349 net). Ratings are for the high-performance 'Super Commando' version (Chrysler Powertrain Guide 1964).
Chrysler Service Manual (Publication 81-270-6401)
Chrysler Electronic Parts Catalog (EPC) Doc. 81-27-110-64
Chrysler Engineering Specification ES-426-V8
Chrysler Engineering Change Order #ECO-426-64
The Chrysler 426 Wedge was used across Chrysler Corporation's B-body and C-body platforms with longitudinal mounting and was not licensed to other manufacturers. This engine received platform-specific adaptations-primarily related to accessory drive layouts and exhaust manifolds for different model trims. All adaptations are documented in OEM factory assembly manuals.
The displacement "426" is cast into the front of the cylinder block, just below the cylinder head deck surface on both sides (Chrysler Service Manual 81-270-6401). There is no separate alphanumeric engine code like later engines; it is identified by its displacement and distinctive tall-deck block. Visually, it can be identified by its large size, cast-iron construction, and the "426" casting mark. It is distinct from the smaller 383 and 413 engines by its bore size and from the later 426 Hemi by its wedge-shaped combustion chambers and valve cover design.
The 426 Wedge's primary long-term reliability consideration is its thirst for high-octane fuel and regular mechanical maintenance. Internal Chrysler service data from the era indicates that the majority of engine failures were linked to detonation from using low-octane fuel or neglecting valve adjustments. The cast-iron block is extremely robust. Regular oil changes and adherence to the valve adjustment schedule are critical for longevity.
Analysis derived from Chrysler factory service manuals (1964-1966) and engineering documentation. Repair procedures should follow manufacturer guidelines.
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