When building a high-performance engine, every component must withstand extreme forces, and the flywheel bolts are no exception. These small but critical fasteners are responsible for securing the heavy flywheel to the crankshaft, a connection that endures immense rotational stress and vibration. Using subpar bolts can lead to catastrophic failure, making the choice of fastener one of the most important decisions in your build.
Automotive Racing Products (ARP) is the industry leader in high-strength fasteners, trusted by professional engine builders and racers worldwide. Their flywheel bolts are engineered from premium materials like chromoly steel and undergo rigorous heat-treating and finishing processes to ensure unparalleled strength and reliability. This roundup focuses on the best ARP flywheel bolts available, helping you select the right kit to keep your high-performance application securely fastened under pressure.
Our Top Picks for ARP Flywheel Bolts
- ARP 330-2802 Flywheel Bolt Kit
- ARP Flexplate Bolt Kit, Pro Series, for GM/Ford V6 / V8
- ARP 3302802 Pro Series Flywheel Bolt Kit, Black
- ARP Flywheel Bolt Kit, Pro Series, for Small Block Ford
- ARP 2082802 Pro Series Flywheel Bolt Kit for Honda
- ARP 134-2501 Balancer Bolt Kit
- ARP 200-2501 High-Performance Flywheel Bolt Kit
- ARP 200-2502 Pro Series Flywheel Bolts
ARP 330-2802 Flywheel Bolt Kit
This ARP flywheel bolt kit is a solid choice for builders who require reliable fasteners for demanding applications. As part of ARP’s extensive lineup, it is manufactured in the United States to the high standards the brand is known for. The kit comes ready to install, providing everything needed for a secure flywheel attachment.
The precise engineering behind these bolts ensures a perfect fit and consistent clamping force, which is fundamental for maintaining balance and integrity in a high-revving engine. The package dimensions indicate a compact kit that is easy to store and handle, containing all the necessary components for your project.
ARP Flexplate Bolt Kit, Pro Series, for GM/Ford V6 / V8
Designed specifically for GM and Ford V6 and V8 engines, this Pro Series flexplate bolt kit is engineered for maximum strength. The bolts feature a 12-point head design, which allows for a more secure tool grip and higher torque application compared to standard hex heads, reducing the risk of rounding. Constructed from chromoly steel and finished with a protective black oxide coating, these bolts resist corrosion and handle high stress with ease.
With a thread size of 7/16-20 and a length of 0.680 inches, this set of six bolts is tailored for a precise fitment on a wide range of popular American engines. Whether you’re assembling a new performance motor or replacing worn factory fasteners, this kit provides the durability needed for a reliable connection between the crankshaft and flexplate.
ARP 3302802 Pro Series Flywheel Bolt Kit, Black
The ARP 3302802 is another standout option from the renowned Pro Series. These bolts are built to deliver exceptional performance in high-horsepower and high-torque environments. Like other ARP products, they are proudly made in the United States, ensuring top-tier quality control and material sourcing.
The black finish not only gives the bolts a professional, clean look but also adds a layer of protection against the elements. The consistent quality and reliable performance of this kit make it a go-to for engine builders who will not compromise on the integrity of any component in their drivetrain assembly.
ARP Flywheel Bolt Kit, Pro Series, for Small Block Ford
This kit is specifically engineered for Small Block Ford applications, ensuring a perfect match for your engine build. The bolts are 7/16-20 in thread and 0.925 inches long, a specification designed to fit a range of popular Ford configurations. The 12-point head allows for high torque values without slipping, which is essential for achieving the correct preload.
Made from high-strength chromoly steel and treated with a black oxide finish, these fasteners offer excellent resistance to shear and tensile forces. Using application-specific kits like this one eliminates guesswork and ensures a hassle-free installation process, giving you confidence in the final assembly.
ARP 2082802 Pro Series Flywheel Bolt Kit for Honda
For Honda performance enthusiasts, this ARP Pro Series kit provides a direct upgrade from factory fasteners. It is designed to meet the specific demands of Honda engines, which are often subjected to high-RPM operation in both street and racing contexts. The kit includes all the necessary bolts for a secure installation.
The precision manufacturing guarantees a correct fit, preventing any potential issues with thread engagement or clearance. Upgrading to these bolts is a smart step for anyone building a turbocharged, supercharged, or high-compression Honda engine where factory bolt strength may be insufficient.
ARP 134-2501 Balancer Bolt Kit
While technically a balancer bolt kit, this ARP product is included for its relevance in securing another critical rotating assembly component. ARP is synonymous with strength, and this kit lives up to that reputation, providing a robust fastener for the crankshaft harmonic balancer. A failure here can be just as damaging as a flywheel failure.
This kit is designed for street, off-road, and powersport applications, demonstrating its versatility across different types of builds. Choosing ARP for this component ensures that you are using a precision product that will maintain torque and stay secure under the constant vibration and harmonic forces present in any engine.
ARP 200-2501 High-Performance Flywheel Bolt Kit
The ARP 200-2501 is a high-performance flywheel bolt kit built for serious engine builds. As part of ARP’s extensive catalog, it is constructed from premium materials to withstand the extreme forces generated by high-horsepower and high-torque applications. The engineering focus is on providing a fastener that will not stretch or yield under load.
Using a kit like this provides significant peace of mind, knowing that the connection between your crankshaft and flywheel is one of the strongest links in your drivetrain. It is an essential upgrade for any build where reliability is paramount, from drag racing to road course competition.
ARP 200-2502 Pro Series Flywheel Bolts
Completing our list is the ARP 200-2502 Pro Series flywheel bolt set. These bolts embody the core principles of the Pro Series line, offering superior strength and reliability through advanced metallurgy and manufacturing processes. They are designed to be a direct replacement for OE fasteners where a higher safety margin is required.
Engine builders select Pro Series components for their proven track record in the most demanding motorsports environments. Installing this kit is a straightforward way to increase the durability and safety of your engine’s rotating assembly without any modifications, making it a smart choice for both seasoned professionals and dedicated hobbyists.
Buying Guide: How to Choose the Right ARP Flywheel Bolts
When you’re building an engine to handle serious power, you can’t afford to cut corners on the parts that hold everything together. The flywheel bolts are a perfect example of a small component with a massive job. I’ve seen too many projects delayed or damaged by using the wrong fasteners. That’s why I always look to ARP for my high-performance needs. But even within the ARP catalog, you need to know what you’re looking for to get the right set of ARP flywheel bolts for high-performance use.
The first thing I check is the material. ARP offers bolts made from different grades, primarily their 8740 chrome-molybdenum steel and the even stronger 625+ alloy. For most street and mild race applications, the 8740 chromoly bolts are more than sufficient. They’re incredibly strong and a significant upgrade over stock. However, if you’re building an all-out drag or race engine with extreme cylinder pressure and RPM, the 625+ alloy is the way to go. It offers superior tensile and fatigue strength, which is the kind of insurance policy I want when pushing the limits.
Next, you need to get the specifications exactly right. This seems obvious, but it’s a common pitfall. You must know the thread size, thread pitch, and length required for your specific engine and flywheel combination. A bolt that’s too long can bottom out and not clamp properly, while one that’s too short won’t engage enough threads. I always cross-reference the ARP part number with my engine’s service manual and physically test-fit a bolt if possible. Don’t forget the underhead length, as this can vary between applications.
Another critical detail is the head style. Most factory flywheel bolts have a washer head, but many aftermarket flywheels, especially lightweight ones, require a standard hex head bolt that uses a separate washer. Using the wrong head style can lead to improper clamping force and a dangerous failure. Always confirm what your flywheel manufacturer specifies.
Finally, consider the installation process. ARP bolts are typically torqued using a lubricant like their proprietary ARP Ultra-Torque. This lubricant is crucial because it ensures consistent clamping force for a given torque value. Using engine oil or a different lubricant can result in a different preload, which is a risk I’m not willing to take. Following ARP’s specific torque sequence and value is non-negotiable for a secure and reliable installation. Taking the time to choose the correct bolts will give you the confidence to push your engine hard, knowing the connection between your crankshaft and flywheel is solid.
FAQ
Why can’t I just reuse my stock flywheel bolts?
This is one of the most common questions I get, and the answer is simple: you shouldn’t. Stock flywheel bolts are often torque-to-yield (TTY), meaning they are stretched to their yield point during installation and are designed for a single use. Reusing them means they’ve already been permanently deformed and will not provide the same clamping force, creating a major risk of failure under high load. Even if they aren’t TTY, the repeated stress and heat cycles weaken them over time. For a high-performance build, starting with new, high-strength ARP flywheel bolts for high-performance use is a fundamental safety measure.
How important is the torque sequence and lubricant?
Extremely important. This isn’t a place for guesswork. The torque sequence, which is usually a star or cross pattern, ensures the flywheel is pulled down evenly against the crankshaft flange without warping. The lubricant is equally critical. ARP designs their torque specs around their specific lubricants, like ARP Ultra-Torque. Using a different lubricant, or none at all, creates a different amount of friction, which means the same applied torque will result in a different clamping force on the bolt. Using the wrong lube can lead to a bolt that is either too loose or over-torqued to the point of failure.
What’s the difference between a standard hex head and a washer head bolt?
The difference is in the design and application. A washer head bolt has an integrated, wider flange under the head that acts as its own washer. This type is common on many OEM applications. A standard hex head bolt requires a separate hardened washer. The choice isn’t up to you; it’s determined by the flywheel. The mounting holes in an aftermarket flywheel are often counterbored to accept a standard hex head and washer. Using a washer head bolt in a counterbored hole means it won’t clamp correctly. Always match the bolt head style to what your flywheel is designed for.
Do I need to use thread locker on my flywheel bolts?
Generally, no, and it can even be counterproductive if not specified. A properly torqued flywheel bolt, especially an ARP unit, creates immense clamping force that prevents loosening. ARP typically recommends their lubricant alone. Using a thread locker can alter the friction and lead to an incorrect preload. Some engine builders might use a very small amount of a low-strength thread locker for peace of mind, but you should only do this if it is explicitly recommended in the instructions for your specific ARP bolt kit. When in doubt, follow ARP’s published procedure.
Can I use ARP flywheel bolts with any aftermarket flywheel?
In most cases, yes, but you must verify compatibility. The primary concerns are the thread size/pitch in the crankshaft, the underhead length, and the head style, as we discussed. Most quality aftermarket flywheel manufacturers will list which ARP kit number is compatible with their product. I always check the manufacturer’s website or instruction sheet to confirm the correct ARP part number before purchasing. This extra step ensures a perfect fit and avoids any installation headaches.