The Complete Guide For Buying Exhaust Manifold
In an internal combustion engine, the exhaust manifold collects the exhaust gases from cylinders and guides them to a single exhaust pipe, which transfers it further to the exhaust system for treatment. Although the exhaust manifold is a simple component and can last the entire vehicle’s life, it can get corroded, damaged, and blocked with time. This can lead to the poor performance of the vehicle. Thus it is very necessary to dive deeper into what exhaust manifolds are. Our comprehensive guide on exhaust manifolds will help you gather knowledge about the exhaust manifolds and aid you in making a wise choice while purchasing one for your vehicle.
In this article:
1. What Is An Exhaust Manifold?
- What are Exhaust Manifolds Made of?
- What Does an Exhaust Manifold Look Like?
- How many Exhaust Manifolds Does a Car Have?
- Where is the Exhaust Manifold Located on a Car?
2. What Type Of Exhaust Manifold Should I Choose?
3. What Are The Factors I Should Consider Before Buying Exhaust Manifold?
4. Which Popular Brand Exhaust Manifold Should I Choose?
- Dorman (OE Solutions) Exhaust Manifolds
- BD Diesel Exhaust Manifolds
- Crown Automotive Jeep Replacement Exhaust Manifolds
5. How Much Should I Pay For A New Exhaust Manifold ?
6. What Are The Signs That My Exhaust Manifold Is Bad?
7. FAQ’s
1. What Is An Exhaust Manifold?
An exhaust manifold is an integral part of the engine and it performs the important task of evacuating the exhaust gases from the engine. The exhaust manifold is a set of tubes attached to the engine that collects the exhaust gases from the cylinders and guides them to the exhaust system. Not only does the exhaust manifold receive all of the burnt engine gases, but also it completely burns any unused or incomplete burnt gases using its very high temperature. The exhaust manifold plays an important role in the performance of the engine by reducing the back-pressure and maintaining the proper flow of the exhaust gases.
What are Exhaust Manifolds Made of?
Exhaust manifolds are typically made of cast iron or stainless steel. Cast iron is a popular choice for exhaust manifolds because it is durable, heat-resistant, and cost-effective. Stainless steel is another popular option as it is resistant to corrosion and lasts a long time. Aftermarket tubular exhaust manifolds, also known as headers, are made of mild steel or stainless steel tubing for the primary tubes along with flat flanges and possibly a larger diameter collector made of a similar material as the primaries. They may be coated with a ceramic-type finish, painted with a heat-resistant finish, or bare.
What Does an Exhaust Manifold Look Like?
An exhaust manifold is a component of an engine’s exhaust system that collects exhaust gasses from the exhaust ports of the various cylinders and conducts them to a central exhaust passage.
How many Exhaust Manifolds Does a Car Have?
The number of exhaust manifolds in a car depends on the engine’s configuration. Engines with two, three, or four cylinders have one exhaust manifold because there is only one bank of cylinders to extract exhaust gasses from. However, engines with a V-shaped arrangement (V6, V8, and V12) have two exhaust manifolds, one for each bank of cylinders.
Where is the Exhaust Manifold Located on a Car?
The exhaust manifold is located between the engine cylinder head and catalytic converter. It collects exhaust gas as it leaves the cylinder head.
Top Picks For Exhaust Manifold
2. What Type Of Exhaust Manifold Should I Choose?
The design and construction of exhaust manifolds can significantly affect the performance and engine characteristics in various ways. To understand more about exhaust manifolds, let’s look at the different types and designs.
According To Construction
1. Cast Exhaust Manifolds
Cast exhaust manifolds are a one-piece design that is cast into a final shape. Most cars are equipped with cast exhaust manifolds as they are cheap and easy to manufacture. However, the short-tube design of cast exhaust manifolds creates interference between the cylinders that causes a restriction to the engine. Cast exhaust manifolds are heavy and negatively affect the fuel economy of the vehicle.
2. Tubular Exhaust Manifolds
Tubular exhaust manifolds feature individual pipes for each cylinder that solves the interference problem of the cast exhaust manifolds. The individual pipes allow free passage of exhaust gases without intermixing and interference. Tubular exhaust manifolds are made from different materials like stainless steel, cast iron, and titanium. Tubular manifolds come in different patterns where four pipes merge into two and one pipes, depending on the engine cylinders and header design. The 4-2-1 and four into one tubular manifold are very common and are used in performance cars and also as an upgrade.
According To Materials
Exhaust manifolds are made from different materials like cast iron, stainless steel, and titanium. Each of these materials has its own advantages and disadvantages.
1. Cast Iron Exhaust Manifolds
Exhaust manifolds made from cast iron are used on several vehicles and are relatively cheap. This material is durable and can have a long life span. Cast iron manifolds have better heat-absorbing capabilities that prevent the exhaust heat from damaging the other components. Cast iron exhaust manifolds are comparatively heavy, brittle, and can crack with heat cycles. Cast iron exhaust manifolds come as standard in several modern vehicles as they are durable and cheap to manufacture.
2. Stainless Steel Exhaust Manifolds
Stainless steel exhaust manifolds are a very good investment when it comes to corrosion-resistance, aesthetics, and long-term usage. Exhaust manifolds are exposed to very high temperatures, pressure, dust, water, and other external elements that can lead to rust. Stainless steel exhaust manifolds can withstand prolonged exposure to these elements, but they often turn blue near the head flange when exposed to high temperatures for a long time. Stainless steel exhaust manifolds can also come with ceramic coating for engines that are designed to run at high engine speeds.
3. Titanium Exhaust Manifolds
Titanium is used in aeronautical parts and jet engines as it is light and very durable. However, titanium is also used in vehicles and to manufacture exhaust manifolds as it can withstand very high temperatures and is corrosion resistant. Titanium exhaust manifolds are usually used in racing applications and performance cars and are very expensive.
According To Layout
There are two main ways in which the individual pipes join. They can either all meet at the same point or they can become pairs that then join together to form a single pipe to the back of the car. Exhaust manifold layouts can be identified just by looking at them. Exhaust manifolds are usually designed in a 4-2-1 and 4-1 layout.
The 4-2-1 manifold layout comprises 4 pipes that merge into 1 pipe. This type of layout offers good mid-range power and is perfect for street usage. They are used on 4 cylinder and 8 cylinder engines as well because they have 4 cylinders on each side.
The 4-1 layouts are designed in such a way that all the 4 pipes merge into one. This type of manifold layout offers excellent top-end power at high engine speeds. The 4-1 exhaust manifolds have less back-pressure than the 4-2-1 ones and are ideal for racing and performance applications.
According To Length
The length of the exhaust manifold matters a lot when it comes to achieving the maximum out of your engine. Exhaust manifolds can be categorized as short tube and long tube exhaust manifolds.
1. Short Tube Exhaust Manifolds
Short tube exhaust manifolds are used in engines with limited space and lowered cars that have limited engine bay area. Short tube manifolds are also known as “shorty headers”, and they work well with the factory exhaust systems. Short tube exhaust manifolds scavenge the gas from the cylinders equally and offer consistent power.
2. Long Tube Exhaust Manifolds
Long tube exhaust manifolds usually come in a 4-1 layout and consist of long primary tubes. They take up a lot of space and are expensive compared to short tube manifolds, but they provide improved scavenging. The long tube exhaust manifolds are ideal for high speeds and are used in racing applications. The long tubes reduce the back-pressure generated and provide a broader power range.
3. What Are The Factors I Should Consider Before Buying Exhaust Manifold?
Exhaust manifolds are made from different metals that can contract, expand, and develop cracks over time. This can disrupt the air-fuel mixture and decrease the performance of your vehicle. Here are a few points to consider while purchasing an exhaust manifold for your vehicle.
1. OEM vs Aftermarket Exhaust Manifold
Due to manufacturing cost constraints, the OEM exhaust manifolds are made from cast iron and are prone to rust and corrosion. Aftermarket exhaust manifolds, on the other hand, are made from different materials like stainless steel, mild steel, and aluminized steel for better performance. Aftermarket exhaust manifolds are expensive compared to OEM manifolds and offer numerous benefits like more power, improved fuel economy, and better sound.
2. Thermal Insulation
Exhaust manifolds are offered with different types of thermal insulation to keep the engine bay from overheating. Exhaust wrap, ceramic paint, and ceramic mixture are the most common types of insulations. Exhaust wraps are wrapped around the exhaust manifolds to contain the heat and are very cheap. Ceramic paint is sprayed or brushed on the exhaust manifolds to reduce the heat radiation. Ceramic mixture offers excellent thermal insulation and is used on performance vehicles and race cars.
3. Material
Exhaust manifolds are also offered in different materials that significantly affect the performance of the vehicle. Stainless steel exhaust manifolds are corrosion resistant and they offer a chrome-like finish adding to the aesthetics of the vehicle. However, stainless steel exhaust manifolds are expensive compared to other types. Aluminized steel exhaust manifolds are made by forming a layer of oxide that prevents rust and corrosion. Aluminized steel exhaust manifolds are lighter and cheaper than stainless steel manifolds but can rust easily once the oxide layer gets damaged. Cast iron exhaust manifolds are widely used and they come as a standard in most vehicles. They are affordable, comparatively heavy, and they do not increase the performance of the vehicle.
4. Which Popular Brand Exhaust Manifold Should I Choose?
Dorman (OE Solutions) Exhaust Manifolds
Dorman (OE Solutions) offers reliable and perfect fitment exhaust manifolds for your vehicle. Exhaust manifolds by Dorman (OE Solutions) are manufactured from high-quality materials to provide the best performance and the perfect replacement for your worn-out factory piece.
Part Number: 674-940, 674-870, 674-982, and more.
Features:
- Perfect fitment exhaust manifold and easy to replace.
- High-quality construction to protect against warping and cracking.
- Leak-resistant and durable for long-lasting performance.
- Manufactured to meet high-performance standards.
- Heat-shield protection for wiring, hoses, and other components.
For more information and a detailed product line, visit the Dorman (OE Solutions) Exhaust Manifolds section.
BD Diesel Exhaust Manifolds
BD Diesel Exhaust Manifolds are designed to extract maximum power from your vehicle and withstand high temperatures. Exhaust manifolds are an important part when it comes to the overall performance of the vehicle, and exhaust manifolds by BD Diesel are manufactured to maximize your vehicle’s true potential.
Part Number: 1045987, 1041480, 1041460, and more.
Features
- Designed from quality materials to enhance the performance of your vehicle.
- Reliable construction resists warping and cracking, ensuring a longer life.
- Trouble-free, leak-free, and consistent performance.
- Manufactured with state-of-art equipment to meet strict industry standards.
- Engineered according to OE specifications for a perfect fit.
For more information and a detailed product line, visit the BD Diesel Exhaust Manifolds section.
Crown Automotive Jeep Replacement Exhaust Manifolds
Crown Automotive Jeep Replacement offers exhaust manifolds for all your needs. If you need simple, bolt-in replacements or you wish to extract extra horsepower from your vehicle, Crown Automotive Jeep Replacement offers a wide range of exhaust manifolds made from different materials like steel, stainless steel, and cast iron.
Part Number: 4666024AD, 4666026AB, and more.
Features
- Manufactured for improved vehicle performance.
- Direct fit replacement makes it easy to install and replace without any modifications.
- Manufactured from high-quality materials for durability and long life.
- Tested for quality and reliability.
For more information and a detailed product line, visit the Crown Automotive Jeep Replacement Exhaust Manifolds section.
5. How Much Should I Pay For A New Exhaust Manifold ?
The cost of aftermarket exhaust manifolds can vary depending on the type, material, and vehicle. The exhaust manifold replacements on PartsAvatar can cost you from $60 to $1200. The price range includes single exhaust manifolds and kits. While replacing exhaust manifolds, you will have to purchase new exhaust manifold gaskets that can add extra to the overall cost of the repair.
6. What Are The Signs That My Exhaust Manifold Is Bad?
A cracked or a bad exhaust manifold can exhibit many symptoms and can be detrimental to the performance and efficiency of your vehicle. Exhaust manifolds are heavy-duty in nature, but they can get damaged due to prolonged exposure to heat, moisture, and other external elements. Some symptoms of a bad exhaust manifold are as follows.
1. Noisy Exhaust
One of the most common symptoms of a damaged exhaust manifold is an unusually loud exhaust. The exhaust manifold can crack and leak, leading to a noisy exhaust. This sound can also arise due to a faulty exhaust manifold gasket and increases while accelerating.
2. Decreased Power And Acceleration
A broken or leaking exhaust manifold will cause the exhaust gases to leak, resulting in poor gas flow and performance. This exhaust gas leak can also be sucked back into the engine, reducing the air-fuel mixture. This can negatively affect the acceleration and power of your vehicle.
3. Poor Fuel Economy
The exhaust manifold leak can reduce the power of the engine. This makes it hard for the engine to perform the task, thus requiring more fuel. Therefore, a failing exhaust manifold can reduce the fuel efficiency of the vehicle.
4. Smell From The Engine Bay
A cracked or damaged exhaust manifold can cause the hot exhaust gases to leak and burn the plastic or rubber components in the engine bay. This can lead to a burning odor in the engine bay.
5. Gasoline or Diesel Odor
A failing exhaust manifold can cause the exhaust gases to leak and enter the cabin of the vehicle. This can lead to strong gasoline or diesel odor in the cabin.
7. FAQ’s
Q. Will driving with a damaged exhaust manifold affect my engine?
A damaged exhaust manifold will not damage your engine but will reduce the performance and fuel efficiency. A leaking exhaust manifold can also damage the components and wiring in the engine bay.
Q. What is the difference between exhaust headers and exhaust manifolds?
Exhaust headers are aftermarket upgrades to exhaust manifolds and are designed for performance applications. Exhaust headers use individual tubes of each cylinder, and each of these tubes connects to a collector pipe. Exhaust headers reduce the back-pressure generated compared to exhaust manifolds and offer good performance.
Q. Can a cracked exhaust manifold be repaired?
A cracked exhaust manifold can be fixed with temporary solutions, like a heat-resistant epoxy. But these solutions only last for a short while, and they cannot withstand high temperatures of the exhaust gases. The only option is to replace the exhaust manifold with a new one.
| Dorman (OE Solutions) Exhaust Manifold – Part Number Catalog | |
| Category | Part Numbers |
| Cast Exhaust Manifold | 674697, 674685, 674-522, 674-695, 674-922, 674-987, 674-923, 674-709, 674-782 |
| Tubular Exhaust Manifold | 674-936, 674-521, 674-981, 674-547, 674-815, 674-803, 674-812, |
