When building an engine, you spend a lot of money to buy new parts, especially if they are upgrades. Head studs ensure that your engine parts are firmly held together and don’t come apart when a lot of power is produced.
ARP, known in full as Automotive Racing Products. They are a renowned manufacturer of various products, head studs included.
Their head studs are pretty durable and can withstand extreme pressure. These studs have tons of remarkable features. But are they reusable? Keep on reading to find out.
Table of Contents
- Are ARP Head Studs Reusable?
- How Do I Know ARP Head Studs are Reusable?
- How to Reuse ARP Head Studs?
- How Many Times Can You Reuse ARP Head Studs?
- Why Shouldn’t I Reuse Rusty or Galled Thread ARP Head Studs?
- Are Stretched ARP Head Studs Reusable?
- Is It Advisable to Buy Used ARP Head Studs?
- Can You Use ARP Head Studs from Another Engine?
- Are ARP Head Studs One Use Only?
- Does Mileage Determine the Reusability of ARP Head Studs?
- Will Excessive Torquing Damage ARP Head Studs?
- Does ARP Recommend the Reuse of their Head Studs?
Are ARP Head Studs Reusable?
According to ARP, head studs can be reused. However, certain factors determine reusability. Studs that are corroded or show signs of thread galling ought to be replaced.
Also, the only studs that can be reused are those that have been correctly installed and torqued.
The good news is that if you have a set of ARP head studs, you can reuse them. But before doing so, inspect for any form of damage.
The option to reuse ARP head studs is reasonably cost-effective, especially considering how expensive these studs are.
At the same time, it’s not worth risking your engine parts flying off due to reusing damaged ARP head studs. Therefore, you need to be highly cautious.
How Do I Know ARP Head Studs are Reusable?
Inspection is critical when reusing ARP head studs. We have already mentioned what’s at risk in the above section. If you already have a set of ARP head studs, how can you know that they are fit to be reused?
First, you should start by cleaning them. Over time, ARP head studs get dirty because of the environment they are exposed to.
It can be challenging to determine if they are in excellent condition when they are dirty. After cleaning, look for rust spots. As mentioned earlier, corroded head studs should be replaced.
If your ARP head studs pass the corrosion test, you can then have a look at the threads. Galling is pretty common amongst head studs.
If you notice that the threads are off, order a replacement asap. Once you confirm these two things and everything checks out, you can confidently reuse the ARP head studs knowing they will do their job perfectly.
How to Reuse ARP Head Studs?
Reusing ARP head studs is a straightforward process when the inspection results come out positive. Lube the bolts before torquing them. ARP recommends using their Ultra-Torque lube, which prevents thread galling and ensures accurate clamp load.
The studs aren’t the only ones that should be cleaned. The bolt holes also have to be cleaned. When you are done with that, you can install the ARP head studs and torque them according to the recommended specifications.
How Many Times Can You Reuse ARP Head Studs?
People may tell you that these studs can be reused as often as possible when you ask around. But that’s incorrect. Yes, these studs are durable and reusable.
But that doesn’t mean they are invulnerable to galling or corrosion. The correct answer to how many times you can reuse ARP head studs is – until they yield.
For these studs to be reused in the first place, they must be accurately torqued during the first installation. If torqued incorrectly, they become damaged the next minute they are uninstalled. Therefore, you need to be very keen on torquing ARP head studs.
The next thing is in regards to inspection before reuse. These aren’t the stock head studs that can only be used once. ARP head studs can be reused severally.
But the rule is that they ought to be inspected before every reuse. To emphasize what we have been preaching since the beginning of this article.
Check for corrosion and thread galling. If you spot one or both issues, don’t hesitate to discard them and get new ones.
Why Shouldn’t I Reuse Rusty or Galled Thread ARP Head Studs?
It can be tempting to reuse ARP head studs. After all, a new set will cost you a lot of money. However, you need to evaluate the total cost of your engine rebuild. Is it worth having all these parts blown to bits just because you want to save some dollars on head studs?
Rusty head studs or those showing signs of thread galling have a weak structure. Therefore, when exposed to a lot of pressure, there is a good chance that the head studs will break apart, and that would cause significant damage to your engine bay.
It’s not worth reusing rusty or ARP head studs with galled threads.
Are Stretched ARP Head Studs Reusable?
Stretching of the head studs occurs when you are torquing the stud to the hole. ARP head studs are designed to stretch when being torqued and return to their original state when loosened. This is why they are reusable.
Despite this mechanism, ARP head studs that have been overstretched shouldn’t be reused. A stretch of more than 0.001″ renders a stud not fit for reuse.
Measuring the stretch of a head stud is a bit complicated. You will need a stretch gauge or any other special tool to get the correct measurement. Rarely do ARP head studs over stretch unless they have been abused.
Is It Advisable to Buy Used ARP Head Studs?
It’s always a good idea to buy new parts. This is the only way you are assured of getting a part in the best condition.
Used parts, especially ARP studs, could be damaged or overstretched. Also, if you are not careful with inspection, you could install a faulty stud on your engine, risking the entire setup.
It’s understandable why you may want to buy used ARP head studs. They will be much cheaper. But when you compare the risk involved, it’s not worth it.
Unless the seller is close-by and you can physically inspect the condition of the studs. Don’t go for used studs, no matter how cheap they are.
With a used ARP head stud, you can’t be sure how many times they have been reused. It could be five or more times. Also, you can’t be sure whether the previous owner used to torque the studs correctly when installing them.
Hopefully, you can see that there are a lot of assumptions that have to be made in this scenario. ARP head studs may be reusable, but that doesn’t mean you should opt for second-hand studs.
Can You Use ARP Head Studs from Another Engine?
During the process of building your engine, you may come across friends who are willing to help you with parts. For instance, a buddy could volunteer to give you the ARP head studs they had on their car.
Before installing them, you may want to know whether this is recommendable.
The good news is that you can use ARP head studs from another engine. But you will have to perform the inspection checks we have mentioned earlier. It will also be crucial if they can tell you how many times they have reused the studs on their car.
The good thing about ARP head studs is that they can be used as many times as possible. That’s because they are durable and are designed to be stretched.
When reusing the ARP head studs from another car engine, make sure that you clean and lube them well. This will protect the studs from corrosion.
Are ARP Head Studs One Use Only?
Not really. Do not confuse factory head studs with ARP. Your factory head studs are one use only.
It’s a good idea when you have removed factory head studs to replace them with ARP since they can be reused. You just have to torque them correctly, and everything will be fine.
Does Mileage Determine the Reusability of ARP Head Studs?
Mileage has nothing to do with whether you can reuse ARP head studs. These studs can be reused after thousands of miles. Unless they yield to wear, you can keep on reusing your studs.
Some people have successfully reused ARP head studs more than five times. That proves how durable these studs are. Provided the studs are inspected and torqued according to specifications, they will not get damaged easily.
Will Excessive Torquing Damage ARP Head Studs?
Excessive torquing can damage ARP head studs. If you are new to building an engine, you may unintentionally apply excessive torque to the head studs. Doing so results in overstretching, and the studs can even break.
You must refer to the recommended torque specs. It would be best if you also learned how to use and read a torque wrench.
Learn the differences between ft-lbs and in-lbs. This will play a key role in determining whether ARP head studs can be reused.
Remember, if these studs are incorrectly torqued during the first installation, there won’t be an option to reuse them next time.
Does ARP Recommend the Reuse of their Head Studs?
When you reach out to ARP, they will confirm that their studs are indeed reusable. However, they will inform you about the above factors that determine whether the studs should be reused.