Big block heads

Types of Big Block Heads

Big block heads come in various types that buyers should know to meet their customer needs. They include:

• Cylinder head

  This is a part of an engine that is generally bolted onto the engine block. It is responsible for housing the cylinders and combustion chambers, while providing a surface for mounting the intake and exhaust manifolds. Cylinder heads are further divided into two categories: flathead and overhead valve heads. Flathead big block heads have the combustion chambers located directly above the pistons, while overhead valve heads have the combustion chambers and valves situated above the cylinders and offset from the pistons.

• Intake manifold

  The intake manifold is responsible for distributing the air-fuel mixture from the carburetor or fuel injectors to the engine's cylinders. It directly connects to the big block heads, facilitating its connection to the engine. The intake manifold plays a critical role in engine performance and efficiency. For instance, it has a design consisting of several passages that ensure an even distribution of the air-fuel mixture to all cylinders, which is important for optimal combustion and power generation. Additionally, it maintains a stable pressure and temperature for the air-fuel mixture, contributing to improved engine performance and fuel efficiency.

• Exhaust manifold

  The exhaust manifold collects exhaust gases from the engine's cylinders and channels them into the exhaust system for emission. By directing these gases away from the engine, the exhaust manifold helps to reduce back pressure, thereby improving engine performance and efficiency.

• Valve cover

  Valve covers seal the top of the big block heads, enclosing the valves and rocker arms. They prevent oil leakage from the engine's lubrication system and help maintain proper oil pressure within the head. In addition to their functional role, valve covers are crucial for the engine's aesthetics, with various designs and finishes available to enhance the overall appearance of the engine bay.

• Spark plugs

  Spark plugs are inserted into the big block heads and play a vital role in the engine's ignition system. They generate the spark required to ignite the air-fuel mixture within the combustion chamber, initiating the combustion process that powers the engine. Proper functioning and maintenance of spark plugs are essential for reliable engine performance, fuel efficiency, and emissions control.

Specifications and Maintenance of Big Block Heads

When sourcing bigger block heads, buyers need to understand that they come with different specifications from various manufacturers to meet distinct client needs. Here are some of the critical specifications to expect:

• Material

  The cylinder heads for big block engines are mainly made from two materials, iron, and aluminum. Each of the materials has its pros and cons. For instance, heads made from iron are more durable and resistant to damage. They also don't warp easily. On the flip side, iron heads are heavier and rust easily. Aluminum heads, on the other hand, are lighter. They also offer better heat dissipation. However, aluminum heads are prone to damage from high pressure and temperature. They can also warp easily. Aluminum heads don't rust like the iron big block cylinder heads.

• Compression Ratio

  Big block heads have different compression ratios that affect how the engine runs. The compression ratio is the relationship between the cylinder's total volume and the head's chamber volume. A head with a high compression ratio enables the engine to produce higher power. The only downside of high compression ratio heads is that they are more expensive and need premium fuel to run. On the other hand, big block heads with low compression ratios are affordable and use regular fuel. However, they lack power.

• Flow Rate

  Big block heads have different flow rates that impact the engine's power and efficiency. The flow rate is the amount of air and fuel that can pass through the head in a minute. Heads with high flow rates allow more air and fuel to flow through, resulting in more power and better efficiency. On the flip side, heads with a lower flow rate will have low power output and poor efficiency.

• Cooling Method

  Cooling is an essential aspect of big block heads. When the engine runs, it generates heat. If the heat isn't cooled, the head can warp or crack. Head manufacturers use different methods to cool the head. The cooling method used on a particular head is specified in the product description. Some of the cooling methods include water channels, oil passages, and external cooling fins.

Big block cylinder head maintenance is crucial for maintaining optimal engine performance and durability. Here are some maintenance tips:

• Regular Inspection: Carry out regular inspections and visual checks to identify any signs of wear, damage, or leaks.
• Coolant Changes: Change the coolant regularly as recommended by the manufacturer. Also, ensure the coolant levels are adequate. The block head has water passages that need to be filled to cool the engine effectively.
• Oil Changes: Use high-quality engine oil and change it regularly as per the manufacturer's instructions. The big block head has oil passages that allow oil flow to lubricate the moving parts.
• Cleanliness: Keep the big block head clean. Avoid the buildup of dirt, debris, and carbon deposits. A clean head ensures optimal airflow and prevents damage.
• Torque Specifications: When installing a big block head, use the recommended torque specifications from the manufacturer. Over-tightening or under-tightening can result in damage.
• Prevent Overheating: Take precautions to avoid head overheating. Overheating is one of the major causes of head damage. Ensure the cooling system is functional to prevent overheating.
• Regular Maintenance: Carry out regular maintenance of the engine and its parts, including the big block heads. Follow the manufacturer's maintenance schedule for optimal performance.

How to Choose Big Block Heads

Business buyers need to understand the criteria used to select big block heads for retail purposes. Here are the key factors to consider:

• Engine Compatibility

  Selecting big block heads that are compatible with the most popular engines is essential. Research which engines are most requested by clients. For instance, the Chevrolet 350 or 454 engines are widely used.

• Budget

  Consider the price range of different big block cylinder heads. Balance quality and affordability since some clients may have a limited budget.

• Material

  Choose heads made of durable materials like aluminum or cast iron. Aluminum heads are lightweight and excellent for performance upgrades. Cast iron heads are more affordable and long-lasting.

• Valves

  Big block heads come with different valve sizes and configurations. Research which valves are in high demand. Clients requiring heads for racing will need larger valves. Standard sizes work well for everyday driving.

• Compression Ratio

  The compression ratio affects engine performance. Heads with higher compression ratios are suitable for racing or towing heavy loads. For clients using their vehicles for regular commuting, heads with moderate compression ratios are ideal.

• Brand Reputation

  Consider the reputation of the big block heads supplier. Retailers should work with reputable suppliers that provide quality products. Read reviews and testimonials from other customers.

• Accessories and Additional Components

  Clients may need extra components when installing big block heads. Stock up on compatible intake manifolds, exhaust headers, and gaskets. Consider selling head gasket kits separately.

• Warranty

  Check if the supplier provides a warranty for the big block heads. A reasonable warranty protects the retailer in case of manufacturing defects. Some suppliers also offer after-sales support to help clients install the heads.

• Cooling

  Consider big block heads with inbuilt cooling systems or the option to add cooling channels. High-performance engines tend to overheat. Extra cooling prevents engine damage.

How to diy and replace big block heads

Reconditioning big block cylinder heads can become a DIY project if the right tools and knowledge are at hand. Here are the steps to follow:

• Removing the old heads

  First, the air cleaner, intake manifold, exhaust manifold, and other components are removed to access the big block heads. Next, the head bolts are loosened in a specific sequence to prevent warping the block. Once the bolts are removed, the heads are lifted off the engine block with a hoist or a specialized tool. The head gaskets are scraped off the block, taking care not to damage the surfaces.

• Preparing the new heads

  The new heads are inspected for cracks, warpage, and other damages. The valves are checked to ensure they operate smoothly, and valve springs are tested for the proper tension. Any necessary repairs or replacements are done to ensure the heads are in excellent condition. Then, the new heads are big block Chevy cylinder head bolts lubricated, and the valve train components are installed and adjusted to the manufacturer's specifications.

• Installing the new heads

  A new gasket is placed on the engine block, and the new heads are carefully aligned and positioned on the block. The head bolts are tightened in a specific sequence and to the recommended torque specifications. Once the heads are installed, the cooling system is refilled with the recommended coolant, and the oil is changed to remove any contaminants.

Q&A

Q1: What are the signs of a failing big block cylinder head?

A1: A failing big block cylinder head can show several signs and symptoms. These include persistent overheating of the engine, white smoke coming from the exhaust (indicative of coolant getting into the combustion chamber), oil contamination by coolant (which gives it a milky appearance), loss of engine power, and visible external leaks. If any of these symptoms are present, it's essential to check the cylinder head?

Q2: Can big block heads be upgraded to improve engine performance?

A2: Yes, big block heads can be upgraded to enhance engine performance. High-performance cylinder heads can increase airflow to the engine, improving combustion efficiency and potentially increasing horsepower and torque. When considering upgrades, it's crucial to ensure that all engine components are compatible and that the modifications align with the intended use of the vehicle (street, track, etc.).

Q3: Are big block heads interchangeable between different engine brands?

A3: No, big block heads are not universally interchangeable across different brands of big block engines. Each head is designed to fit a specific engine block, considering unique bolt patterns and cooling passage configurations. For instance, a Chevrolet big block head will not fit on a Ford or Chrysler big block engine.

Q4: What is the difference between cast iron and aluminum big block heads?

A4: Cast iron heads are durable and heat resistant, making them suitable for high-heat applications. They are often more affordable, but they are heavier than their counterparts. On the other hand, aluminum heads are lighter, which can lead to better engine performance and efficiency. Aluminum heads also offer the advantage of quicker heat dissipation. This means they cool down faster compared to cast iron heads. However, aluminum heads can be more expensive than cast iron heads.

Q5: Can damaged cylinder heads be repaired, or should they always be replaced?

A5: In many cases, damaged cylinder heads can be repaired through processes like welding or machining. However, the head's integrity must be thoroughly assessed to determine the extent of the damage. If the damage is too severe or if the head has been compromised in multiple areas, replacement is often the safer and more reliable option.