ARP Head Stud Kit, BMW M50/M52/S50/S52 11mm Oversized

These head studs are a great choice for increasing boost levels without the cylinder head lifting. While both the 11mm L19 and 10mm Custom Age 625+ head studs are high-quality options made to ARP standards, we recommend the 10mm 625+ option. However, the choice ultimately comes down to personal preference.

It's essential to note that precision machining is required when drilling and tapping to prevent thread holes from cranking, which could cause surface damage to the engine block and potentially lead to engine failure.

Installation Instructions: 

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.