However, here's a breakdown of common characteristics and some example specifications for a few popular versions:
General Characteristics:
* Displacement: 455 cubic inches (7.4 liters) - This is the consistent feature across all 455s.
* V8 Configuration: A large-block, 90-degree V8 with a large bore and stroke.
* Known for: High torque output, making it popular for muscle cars and performance applications. Its torque curve was particularly impressive for its time.
Varying Specifications (Examples):
To illustrate the variability, let's look at a few examples. These are *examples* and not exhaustive:
* 1970-1972 High-Performance Versions: These often featured higher compression ratios, more aggressive camshafts, and larger carburetors resulting in higher horsepower ratings (often exceeding 350 hp) and significantly higher torque.
* 1973-1976 Versions: Due to emissions regulations and the oil crisis, horsepower and compression ratios were generally lowered across all engines. The focus shifted towards torque. Horsepower ratings would typically be in the 250-300 hp range.
Key Specifications that Varied:
* Horsepower: Ranged from approximately 250 hp to over 370 hp, depending on the year and model.
* Torque: Generally high, usually in the 400 lb-ft to 500 lb-ft range, depending on the year and model.
* Compression Ratio: Varied significantly depending on the year and model, from relatively high (e.g., 10.5:1 in some early high-performance versions) to lower ratios (e.g., 8:1 or lower in later emissions-controlled models).
* Carburetion: Single or dual four-barrel carburetors were common.
* Camshaft: Different cam profiles were used, affecting power delivery and overall performance.
* Intake Manifold: Various designs were used, affecting performance.
* Exhaust System: Different exhaust manifolds and mufflers were offered, affecting exhaust flow.
To get precise specs, you need to specify:
* Year of the engine: This dramatically impacts the specifications.
* Specific vehicle model: The engine's specifications may vary even within the same year depending on the car in which it was installed (Grand Prix, Bonneville, Catalina, etc.).
In short, "Pontiac 455 specs" is too broad a question. You need to be more specific to get a meaningful answer. A good starting point would be to find a parts catalog or engine specification guide for the specific year and model of Pontiac vehicle you're interested in.
