Upgrade the performance of your BMW N20 / N26 engine with our custom-designed Head Stud Kit, brought to you by ARP - the world leader in fastener technology.
This kit is engineered to replace BMW part #'s 11127620958, 11127583138, and 11122212157 and is compatible with BMW N20 and N26 turbocharged inline-four engines found in a range of 3-Series, 4-Series, 5-Series, and X-Series models.
This kit offers increased clamping force and enhanced head gasket sealing, which can prevent head gasket failure. This is particularly crucial for high-performance and high boost engines, as the increased cylinder pressure puts additional stress on the head gasket and bolts.
Please note, it is a MUST to drill and tap the four outer 10mm holes in the engine block to increase their size to 11mm holes. This will ensure that all the engine block holes are uniform in size and can accommodate all 11mm Studs. Additionally, it will help distribute even force across the cylinder head-gasket surface.
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
Step 1: Tighten to 30 ft-lbs.
Step 2: Tighten to 60 ft-lbs.
Step 3: Tighten to 90 ft-lbs.
with ARP Ultra-Torque fastener assembly lubricant
Bolt Torque Sequence
1 Series
F20
F21
2 Series
F22
F23
3 Series
F30
F31
F34
F35
4 Series
F32
F33
F36
5 Series
F07
F10
F11
F18
X1 Series
E84
X3 Series
F25
X4 Series
F26
X5 Series
F15
X6 Series
F16
Z Series
E89 Z4
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.
