Main points
- The cylinder head number is typically located on the top or side of the head, near the valve cover or intake manifold.
- The engine family code in the cylinder head number often corresponds to the engine’s displacement.
- For example, a cylinder head number with “350” in the family code would indicate a 350 cubic inch engine.
Cylinder head numbers are crucial identifiers for engine components, providing valuable information about the engine’s specifications and history. Understanding how to read these numbers is essential for mechanics, enthusiasts, and anyone working with engines.
Locating the Cylinder Head Number
The cylinder head number is typically engraved or stamped on the head’s surface. It can be found on the top or side of the head, near the valve cover or intake manifold.
Deciphering the Number
Cylinder head numbers usually consist of a series of numbers and letters. The format and content vary depending on the manufacturer, but they generally follow a specific pattern.
1. Manufacturer Code
The first character(s) of the number often indicate the manufacturer of the cylinder head. For example:
- C – Chevrolet
- F – Ford
- M – Mopar
2. Engine Family
The next few characters represent the engine family or series. This indicates the general type of engine the head is designed for.
3. Head Design Code
This code identifies the specific head design. It may include information about the combustion chamber shape, port configuration, and other features.
4. Material Code
Some numbers may indicate the material used in the construction of the head, such as aluminum or cast iron.
5. Date Code
Occasionally, the cylinder head number may include a date code that indicates when the head was manufactured.
Example: Reading a Cylinder Head Number
Let’s consider the following cylinder head number: C460E2
- C – Chevrolet manufacturer
- 460 – Engine family (460 cubic inch)
- E – Head design code (specific design)
- 2 – Material code (aluminum)
Importance of Reading Cylinder Head Numbers
Knowing how to read cylinder head numbers is essential for:
- Identifying Engine Specifications: The head number can help determine the engine’s displacement, compression ratio, and other performance characteristics.
- Matching Head to Block: When replacing a cylinder head, it’s crucial to ensure that the head is compatible with the engine block. The head number will indicate whether the head is designed for that particular engine.
- Troubleshooting Engine Issues: Certain head numbers may be associated with known problems or design flaws. By reading the head number, mechanics can diagnose potential issues more quickly.
- Historical Research: Cylinder head numbers can provide insights into the history and lineage of an engine, which is valuable for collectors and enthusiasts.
Other Considerations
- Variations in Formats: Different manufacturers use varying formats for cylinder head numbers. It’s important to consult manufacturer-specific documentation for accurate interpretation.
- Casting Marks: Some cylinder heads may have additional casting marks or numbers that provide further information, such as the casting date or foundry origin.
- Stamping Errors: Occasionally, cylinder head numbers may contain errors or misprints. If the number is unclear or doesn’t make sense, it’s best to contact the manufacturer for verification.
What You Need to Know
Q: Where can I find the cylinder head number on my engine?
A: The cylinder head number is typically located on the top or side of the head, near the valve cover or intake manifold.
Q: What does the first character of the cylinder head number indicate?
A: The first character usually represents the manufacturer of the cylinder head.
Q: How can I use the cylinder head number to determine the engine’s displacement?
A: The engine family code in the cylinder head number often corresponds to the engine’s displacement. For example, a cylinder head number with “350” in the family code would indicate a 350 cubic inch engine.
Q: Is it important to match the cylinder head number when replacing a head?
A: Yes, it’s crucial to ensure that the replacement head has the same cylinder head number as the original. This ensures compatibility with the engine block and proper performance.
Q: Can I cross-reference cylinder head numbers between different manufacturers?
A: No, cylinder head numbers are specific to each manufacturer and cannot be directly cross-referenced. However, it’s possible to find aftermarket heads that are designed to fit specific engine models from different manufacturers.
