What is the difference between a Ford 240 and a 300 head?
At a glance, the cylinder head from the Ford 300 inline-six is larger and configured differently from the Ford 240 head, so they are not typically a drop-in swap. The 300 head is designed to support a larger displacement with bigger valves and ports, while the 240 head is built for a smaller engine and different flow characteristics.
In more detail, these heads come from two generations of Ford’s inline-six family. Although they share the same basic OHV architecture, they differ in combustion chamber volume, port geometry, valve sizes, and gasket interfaces. Understanding these differences helps when planning a rebuild, upgrade, or swap so you know what to expect for fitment, performance, and reliability.
Key design differences
The following points outline the main design differences you should know when comparing the two cylinder heads.
- Combustion chamber and compression considerations: The 300 head generally accommodates the larger displacement with a different chamber volume, which affects compression ratio and tuning requirements. The 240 head typically has a smaller chamber, potentially yielding higher static compression under certain conditions.
- Valve sizes and port flow: The 300 head usually employs larger intake and exhaust valves and greater port volumes to support higher airflow at the larger displacement, while the 240 head features smaller ports suited to earlier-era performance and torque characteristics.
- Port and gasket geometry: Port shapes and gasket interfaces differ, affecting manifold attachment and sealing. They are not generally interchangeable without addressing these differences.
- Cooling passages and deck height: The two heads reflect different coolant passages and deck geometry, which can influence gasket thickness, coolant flow, and compatibility with the block.
These differences underscore why a straightforward head swap between a 240 and a 300 isn’t typically feasible without accounting for chamber volume, port alignment, and supporting components.
Practical implications and swap considerations
Before attempting any swap or build, evaluate the following practical factors to avoid fitment issues or reliability problems.
- Interchangeability: A 240 head is not automatically compatible with a 300 block, and vice versa. Differences in chamber size, deck height, and port layout can require milling, gasket changes, or custom manifolds.
- Valve train and pushrods: Differences in valve sizes or rocker geometry may necessitate different pushrod lengths or adjustments to valve train components to ensure proper alignment and operation.
- Gasket and manifold compatibility: Use the correct head gasket and verify intake/exhaust manifolds align with the port patterns. In some cases, aftermarket or custom gaskets may be required.
- Compression and fuel strategy: Changing heads affects compression ratio and may require recalibrating carburetion or ignition timing to prevent detonation or poor performance.
- Cooling system fitment: Ensure coolant passages and water jackets align with your engine block and radiator setup to avoid overheating or leaks.
Consult factory manuals or a qualified engine builder to confirm exact compatibility for your year and model. In many cases, maintaining consistency within the same displacement family simplifies fitment and tuning.
Bottom line
The Ford 240 and Ford 300 inline-six heads come from different design generations, with the 300 head offering larger flow capabilities and different combustion chamber geometry, and the 240 head optimized for smaller displacement and earlier-era tuning. They are not typically cross-compatible without careful attention to gasket, port, and mechanical differences.
Summary
In short, the 300 head is generally larger and better suited for the bigger 4.9-liter inline-six, while the 240 head fits the smaller displacement and older performance characteristics. If you plan a swap or build, verify chamber size, port geometry, gasket requirements, and supporting components to ensure a reliable, well-tuned engine. When in doubt, consult a knowledgeable builder or official manuals to confirm exact compatibility for your specific year and model.
What year did Ford go from 289 to 302?
The new 302 replaced the 289 early in the 1968 model year. The most common form of this engine used a two-barrel carburetor, initially with 9.5:1 compression.
Is the Ford 240 a good engine?
Produced at the Cleveland Engine plant in Brook Park, Ohio, from 1965 through 1996, the 240 and 300 inline-six engines are well known for their durability. These engines employed seven main bearings and used long-wearing timing gears instead of a chain or belt.
What is the difference between Ford 240 and 300 head?
The Ford 300 has D shaped combustion chambers. While the Ford 240 and Ford 300 head share the same port and valve sizes, the Ford 240 head has a smaller 68cc combustion chamber vs 78cc for the Ford 300. If a Ford 240 head is installed on a Ford 300, the compression ratio will increase by . 5.
What Ford engine to stay away from?
The 5.4-liter Triton engine is a member of Ford's Modular V8 engine family, introduced in 1997. The three-valve version produced from 2002 to 2008 is the most problematic and one of the most unreliable Ford engines.
