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Main Stud Kit - 2007-2016 1.6L BMW Mini Cooper N12-N14-N16-N18
PART # SKU MP879
Verified Reviews
Original price
£119.00
-
Original price
£119.00
Original price
£119.00
£119.00
-
£119.00
Current price
£119.00
Availability:
in stock, ready to be shipped
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Disclaimer: Designed to secure crankshaft main bearing caps. This is NOT a head stud kit.
Why Main Studs?
Main studs provide superior clamping force compared to main bolts, reducing wear on block threads and assisting with main cap alignment. Unlike bolts, which twist during tightening, studs remain stationary, reducing the chance of main cap walking under high loads. They are especially beneficial in high-performance applications where increased stability and durability are required.
INSTALL GUIDE
This guide covers installation of the XOTIC PERFORMANCE™ MP879 main stud kit for the 1.6L BMW / Mini Cooper N12, N14, N16 and N18. Prefer a printable copy? Download the PDF manual.
Positions 27 and 28 take the 55 mm bolts. This kit has eighteen M6 bedplate bolts, and the last two positions are not the same length as the rest. Identify the 55 mm pair before you start threading anything in — the bedplate torque values are small, and a wrong-length bolt in a shallow hole will feel perfectly normal on the wrench right up until it isn't.
Why an N14 or N18 needs main studs
The BMW / PSA "Prince" 1.6L is a small, hard-working turbo four that responds enormously well to boost and tuning — a Stage 2 N14 or N18 makes power a long way beyond what the factory bottom end was specified for. On an engine this size, the bedplate design is what holds the crank, and every bit of clamping comes from a lot of relatively small fasteners working together. That makes even preload across all of them more important, not less.
Studs do that better than bolts for a structural reason. A bolt is torqued into the block, so it twists and stretches at the same time; a stud is threaded in finger-tight and stays still while the nut is torqued against it, loading the stud in pure tension. The result is more consistent, more accurate preload — the tensile force in the fastener that becomes clamp force in the joint. XOTIC PERFORMANCE™ main studs are manufactured from our premium XOTIC 7200 steel alloy and backed by a lifetime warranty.
What's in the MP879 kit
- 10 × M9 main studs (XOTIC 7200 alloy)
- 18 × M6 bedplate bolts — including the 55 mm pair for positions 27 and 28
- 10 × hardened parallel washers
- 10 × nuts
- 1 × socket
- 1 × allen wrench
- 1 × fastener assembly lubricant
Before you start: verify first
Confirm that part number MP879 is compatible with your application before installing any components. Inspect all package contents for damage and clean as necessary to ensure accurate installation. Sort the bedplate bolts by length now. Report any obvious defects or shipping damage to us before proceeding.
How to install main studs on a Mini Cooper N14 or N18
- Chase the block threads. Clean the threads in the block with a thread chaser prior to installing the studs, to ensure accurate fitment and precise torque readings.
- Thread the studs in by hand. Screw the main studs in as tight as can be made by hand — no tool necessary, and do not apply torque. Loctite may be used for permanent stud installation, but the fasteners must be fully torqued before the Loctite sets.
- Check stud height with a straightedge. Use a straightedge ruler to measure the distance from the mating surface (deck or main cap) to the top of each installed stud. Ensure all studs of the same length group sit level with each other (within 1 mm / 0.040”). Uneven height may indicate debris or incorrect thread engagement. Properly installed studs will bottom out smoothly and show uniform height across all positions. If a stud appears higher or lower than the others, remove it, re-clean the hole, and reinstall by hand. Do not use tools to force studs deeper. Incorrect stud seating can cause off-angle stress, uneven preload, or stud fracture during engine operation.
- Install the main caps. Set the caps in place and ensure appropriate alignment before any load goes on them.
- Lubricate. Using the fastener assembly lubricant included in the package, lubricate the threads of the main studs and the nuts.
- Hand-tighten the nuts. Thread the nuts onto the studs as tight as can be made by hand.
- Torque the M9 nuts in three equal steps. Working in the sequence shown in the manual's torque sequence diagram, tighten positions 1–10 through the three stages below.
- Torque the bedplate bolts. Positions 11–28 get their own three-stage sequence at much lower values — use a small in-lb or low-range ft-lb wrench, not the same tool you used for the mains. Remember the 55 mm bolts at positions 27 and 28.
Mini Cooper 1.6L main stud torque specs
M9 nuts (positions 1–10)
| Stage | Torque |
|---|---|
| 1 | 17 ft-lbs |
| 2 | 34 ft-lbs |
| 3 (final) | 50 ft-lbs |
Bedplate bolts (positions 11–28)
| Stage | Torque |
|---|---|
| 1 | 4 ft-lbs |
| 2 | 8 ft-lbs |
| 3 (final) | 12 ft-lbs |
A common mistake to avoid: when torquing a fastener, do not stop short of the recommended value — continue in one motion until the specified torque is achieved. If you accidentally stop short, loosen the fastener and re-torque. Stopping short and "topping up" produces unequal preload distribution across the bedplate, which matters more here than on a big block because so much of the clamping is shared between small fasteners.
Frequently asked questions
What are the main stud torque specs for a 1.6L Mini Cooper?
The M9 nuts at positions 1–10 go to 17, then 34, then a final 50 ft-lbs. The bedplate bolts at positions 11–28 go to 4, then 8, then a final 12 ft-lbs.
Which bolts go in positions 27 and 28?
The 55 mm bedplate bolts. Set that pair aside before you start so they don't get used elsewhere in the sequence.
Which engines does MP879 fit?
The 1.6L BMW / Mini Cooper N12, N14, N16 and N18 — the naturally aspirated and turbocharged Prince family used across the R56-generation Cooper and Cooper S and their BMW equivalents.
Do I need a second torque wrench?
Practically, yes. The bedplate values top out at 12 ft-lbs, which is at or below the accurate range of a wrench sized for a 50 ft-lb main. Use a low-range wrench for positions 11–28.
Need help?
For technical support, email support@xotic-performance.com. All XOTIC PERFORMANCE™ fasteners are covered by our limited lifetime warranty. Finished your install? Tag #XOTICPERFORMANCE on Instagram for a chance to be featured.
© 2026 XOTIC PERFORMANCE™. This installation guide is an original copyrighted work of XOTIC PERFORMANCE™. Reproduction, distribution, or use of this content in whole or in part without written permission is prohibited. Doc ref: 2026.01.28 (web edition 2026.08).
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