Choosing the right head studs for better engine performance 

HCR Subaru Engine Head Stud Set (11mm and 14mm)

We have launched our own HCR Head Stud Sets (11mm and 14mm) and for better performance results we improved the design of this product.

Mixing our experience and knowledge with an endless desire to improve and invent better solutions for higher engine performance and reliability, we have launched our own HCR Head Stud Sets of 11mm and 14mm threads. We have improved the design of this product to be able to provide our clients with the best head studs for clamping the cylinder heads onto the block assembly to reduce the risk of having a head lift under a higher boost. It all took a considerable amount of our time and other resources, but it paid off.

Our studs differ from others available in the market. There are a couple of features implemented in the design of studs that provide better performance results. 

Our studs come with dog-points. It allows studs to bottom out in a controlled way and provides good distribution along the thread allowing the lower thread to take some of the load before we put tension on the upper part of the block thread. In other words, when tightening studs to a higher tension you are less likely to be able to pull the threads out of your block and damage it. 


In collaboration with Latvia University of Life Sciences and Technologies, we ran a series of tests where with a tensile strength testing machine we compared studs from different manufacturers that are available in the market, including our design. As you already might know, studs are designed to stretch, which plays a valid role in clamping the joint together. We found that before yielding each stud stretches differently from another and that our studs provide more clamping force and higher yield point than compared to other studs on the market. In other words, our studs can achieve a larger clamp force in comparison before yielding, tensile strength is up to 230,000 psi, shown below.

We also studied studs used by World Rally Championship (WRC) cars and found that the shank of the stud is turned down and it is thinner than into the thread range, which allows us to control the stretching into their elastic range. This aspect significantly affects the strength of the stud. During the test where we searched for a yielding point, we found that our stud stretched 3 times more than other known manufacturer studs.


In summarising, we recommend choosing the right head studs for your engine wisely. It is not always about “the bigger the better”, it is more about clamp load, how your studs can deal with it and what is your aim, regardless of thread size. Our HCR 11mm Head Stud Set will be a great solution for the street car enthusiast who plans to see up to around 550hp. We can offer them at a better price than others, ensuring that it will work as well as others and even better. If you plan to go for more power starting from 500+hp we recommend replacing the conventional 11mm threads with a series of 14mm precisely manufactured. These studs have proven themselves on the tests we ran. We also have received good reviews from our clients who already use our head studs. All this convinces us that we can provide the best solution that is available on the market.

Find HCR head studs in our shop here.