ARP Head Stud Kit, BMW M50/M52/S50/S52, Custom Age 625+

In collaboration with ARP, we offer a unique material called Custom Age 625+. This material has a tensile strength of 260 ksi, which is substantially higher than the 190 ksi of the ARP 2000 head stud. It's an ideal choice for individuals who want to push the limits of their M50/M52/S50/S52 Turbocharged and Supercharged engine builds and require a stronger head stud. Using Custom Age 625+ head studs allows you to increase boost levels without the cylinder head lifting, making it unnecessary to use an 11mm stud or drill and tap your block.

Using Custom Age 625+ head studs enables you to increase boost levels without worrying about the cylinder head lifting. This means that you won't need to use an 11mm stud or drill & tap your block.

1. To ensure proper thread engagement and accurate torque readings, clean ALL threads in the block. Chase if necessary with ARP Thread Chaser.

2. Clean and inspect all hardware prior to installation. Look for obvious defects or shipping damages, plus proper fit, length and dimension.

3. If the cylinder head studs protrude into a water jacket, lubricate the block threads of the studs with ARP THREAD SEALER.

4. Screw studs into the block “HAND TIGHT ONLY”.

5. Install the cylinder head(s) and check for binding or misalignment.

6. Lubricate the stud threads, nuts and washers with ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT.

Then install the washers and the nuts onto the studs and tighten them hand tight.

ARP recommends using the ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT that is provided with each kit as opposed to motor oil. This is due to higher friction on the studs as well as inconsistencies in the clamping force of the fasteners when motor oil or other low quality lubricants are used.

PRELOAD (TORQUE) RECOMMENDATIONS

7. Following the manufacturers recommended torque sequence tighten the nuts steps 1-3

with ARP Ultra-Torque fastener assembly lubricant

12	10	4	2	6	8	14
13	7	5	1	3	9	11

 

Please note: After initial assembly, it is necessary to allow the engine to complete a full heat cycle, then re-torque your head studs to spec. This means allowing the engine to warm up to its normal operating temperature, remain at operating temperature for several minutes to ensure each component is uniformly heated, then turned off and cooled completely to ambient temperature.