Small block Chevy engines are a popular choice for performance enthusiasts due to their versatility, reliability, and aftermarket support. One of the most important components of any engine is the cylinder heads, which play a critical role in controlling airflow, combustion, and power output. In the world of small block Chevy engines, there has been an ongoing debate between two types of cylinder heads: 18 degree and 23 degree. While both offer their own advantages and disadvantages, choosing the right one can make a significant difference in overall engine performance. In this article, we will compare 18 degree vs. 23 degree SBC heads and help you decide which is best for your engine build.
Contents
18 Degree SBC Heads
18 degree SBC heads are a newer design that offers several benefits over the older 23 degree design. The name “18 degree” refers to the angle between the intake and exhaust valves in the cylinder head, which is more upright than the 23 degree angle of traditional heads. This design allows for larger, straighter ports and better airflow, which can result in higher power output.
One of the biggest advantages of 18 degree SBC heads is their compatibility with different engine configurations. They can be used on both small and big block Chevy engines, as well as aftermarket blocks. This makes them a versatile option for many different engine builds.
Another benefit of using 18 degree SBC heads is increased combustion efficiency. The straighter ports and more upright valve angle allow for a more direct path for the air/fuel mixture to enter the combustion chamber, which can result in better fuel economy and lower emissions.
In addition, 18 degree SBC heads allow for the use of more aggressive camshafts, which can further increase power output. They also tend to run cooler than traditional heads, which can be beneficial in high-performance applications.
However, there are also some potential downsides to using 18 degree SBC heads. They are typically more expensive than traditional heads, and may require specialized components such as intake manifolds and valve covers. Availability can also be an issue, as not all aftermarket manufacturers offer 18 degree heads. It’s important to weigh these factors against the potential benefits before making a decision on which type of cylinder head to use.
23 Degree SBC Heads
23 degree SBC heads are the traditional design that has been used for decades in small block Chevy engines. The name “23 degree” refers to the angle between the intake and exhaust valves in the cylinder head, which is more angled than the 18 degree angle of newer heads.
One of the biggest advantages of using 23 degree SBC heads is their availability and lower cost. Since they have been used in small block Chevy engines for many years, they are widely available from both OEM and aftermarket manufacturers, and can often be found at a lower cost than 18 degree heads.
Another benefit of using 23 degree SBC heads is their compatibility with a wide range of components. Since they are a traditional design, they are compatible with many different intake manifolds, valve covers, and other components, making them a versatile choice for engine builders.
However, 23 degree SBC heads also have some potential drawbacks. Their angled valve design can result in less direct airflow into the combustion chamber, which can limit power output compared to newer 18 degree heads. They may also be limited in terms of camshaft choice, as more aggressive camshafts can cause clearance issues with the angled valves.
Overall, choosing 23 degree SBC heads can be a good option for engine builders who are looking for a lower-cost, versatile option that is compatible with a wide range of components. However, those looking for maximum power output and efficiency may want to consider newer 18 degree heads.
Which SBC heads offer better performance, 062 vs 906 or 18 degree vs 23 degree?
When comparing 062 and 906 heads for SBC engines, the choice between 18 degree and 23 degree heads comes down to performance goals. 18 degree heads can provide better airflow and power at higher RPMs, while 23 degree heads offer better low-end torque and drivability. Both have their advantages depending on your specific needs.
Comparison between 18 Degree and 23 Degree SBC Heads with table
To help summarize the differences between 18 degree and 23 degree SBC heads, the following table compares some key factors:
| Factor | 18 Degree SBC Heads | 23 Degree SBC Heads |
| Valve Angle | 18 degrees | 23 degrees |
| Port Shape | Straighter | More angled |
| Compatibility | Can be used on small and big block Chevy engines, as well as aftermarket blocks | Mostly used on small block Chevy engines |
| Power Output | Can result in higher power output due to better airflow | May be limited compared to 18 degree heads |
| Camshaft Compatibility | Can handle more aggressive camshafts | May be limited with more aggressive camshafts |
| Cost | Generally more expensive | Generally less expensive |
| Availability | Not as widely available as 23 degree heads | Widely available |
As you can see, both 18 degree and 23 degree SBC heads offer their own advantages and disadvantages. Ultimately, the choice between the two will depend on the specific needs of the engine build, including power goals, budget, and compatibility with other components. It’s important to carefully consider these factors before making a decision on which type of cylinder head to use.
FAQ:
Q: Can 18 degree SBC heads be used on any small block Chevy engine?
A: No, 18 degree SBC heads are designed specifically for newer small block Chevy engines that have a raised intake runner location. They may not be compatible with older engines that have a lower intake runner location.
Q: Are 23 degree SBC heads more affordable than 18 degree heads?
A: Generally, yes. 23 degree SBC heads are a traditional design that has been around for many years and is widely available. As a result, they are often less expensive than newer 18 degree heads.
Q: Can 23 degree SBC heads be used on big block Chevy engines?
A: It’s possible, but it may not be the best choice. 23 degree SBC heads are designed specifically for small block Chevy engines, and may not offer the same level of compatibility or power output on big block engines.
Q: Do 18 degree SBC heads require special components?
A: Yes, because of their larger size and newer design, 18 degree SBC heads may require specialized components such as intake manifolds and rocker arms that are designed specifically for use with this type of cylinder head.
Q: Which type of SBC head is better for maximum power output?
A: In general, 18 degree SBC heads are considered better for maximum power output due to their larger, straighter ports and better airflow. However, the specific needs of the engine build and compatibility with other components should also be considered when making a decision on which type of head to use.
Conclusion:
Choosing the right cylinder heads is a crucial part of any engine build, and in the world of small block Chevy engines, the choice often comes down to 18 degree vs. 23 degree SBC heads. Both types offer their own benefits and drawbacks, and the decision on which one to use will ultimately depend on the specific needs of the engine build.
18 degree SBC heads offer a newer design with larger, straighter ports and better airflow, which can result in higher power output and increased combustion efficiency. They are also compatible with different engine configurations and can handle more aggressive camshafts. However, they are generally more expensive and may require specialized components.
23 degree SBC heads offer a traditional design that is widely available and compatible with a wide range of components. They are generally less expensive and may be a better choice for engine builders on a budget. However, their angled valve design can limit power output compared to 18 degree heads, and they may be limited in terms of camshaft compatibility.
Ultimately, the choice between 18 degree and 23 degree SBC heads will depend on the specific needs of the engine build. It’s important to carefully consider factors such as power goals, budget, and compatibility with other components before making a decision. With the right cylinder head choice, you can help ensure maximum performance and efficiency from your small block Chevy engine.
