Follow step-by-step instructions for installing HCR 14mm Head Studs:
1. Lubricate the studs block end threads with engine oil or assembly lube.
2. Screw the studs in the block to approx. 10Nm (hand tight with 3/16 allen wrench).
If any resistance is felt – stop! If you experience resistance, back out the stud and inspect the threads on both parts; clean the threads as needed. Try threading it again.
3. Verify stud height relative to each other stud. If everything is done right, all studs should be +/- 0,3mm relative height to each other.
4. Install the head gasket and supply a torque lube all around the top of the threads.
5. Install the cylinder head. Be sure that both surfaces of the washer and cylinder head are degreased.
6. Apply torque lube to flange part of the head stud nut and install it.
7. Follow this torque procedure:
| Step NR | Center two | Outer four |
| Step 1 | 55Nm | 40Nm |
| Step 2 | 115Nm | 95Nm |
| Step 3 | 155Nm | 150Nm |
| Step 4 | 175Nm | 175Nm |
| Step 5 | Check if all studs are tight! | |
HCR 14mm Head Studs are suitable for all Subaru EJ20/22/25 series engines. We have improved the design of the threads and tested it, to make sure that we can provide the best solution for clamping the cylinder heads onto the block assembly to reduce the risk of having a head lift under a higher boost. Learn more about the improvements here.
Follow step-by-step instructions for installing HCR 11mm Head Studs:
1. Lubricate the stud’s block end threads with engine oil or assembly lube.
2. Screw the studs in the block to approx. 10Nm (hand tight with 5mm allen wrench).
If any resistance is felt – stop! If you experience resistance, back out the stud and inspect the threads on both parts; clean the threads as needed. Try cleaning threads.
3. Verify stud height relative to each other stud. If everything is done right, all studs should be +/- 0,3mm relative height to each other if everything is done right.
4. Install the head gasket and apply torque lube to all around the top of the threads.
5. Install the cylinder head. Be sure that both surfaces of the washer and cylinder head are degreased.
6. Apply torque lube to flange part of the head stud nut and install it.
7. Torque the heads to 120Nm in 3 equal steps (40Nm, 80Nm, 120Nm), from middle to outside.
HCR 11mm Head Studs are suitable for all Subaru EJ20/22/25 series engines. We have improved the design of the threads and tested it, to make sure that we can provide the best solution for clamping the cylinder heads onto the block assembly to reduce the risk of having a head lift under a higher boost. Learn more about the improvements here.
YOU’RE done! Thank You for respecting your engine!
