Reinforced ARP bolts for OEM rods MINI BMW PSA N12 N13 N14 N16 N18 EP6

The engines concerned

This kit is intended for the 1.6-litre 16-valve engines of MINI (N12, N14, N16, N18), BMW (N13B16) and PSA (EP6). On the MINI models alone, output runs from the One at 75 hp to the John Cooper Works GP at 218 hp.

The original rod bolt of the N12, N14, N18 and EP6 carries the reference 11 24 7 593 922 (M7 x 37 mm): the manufacturer prescribes tightening it new, washed and oiled, to 5 Nm, then 15 Nm, then 130 degrees, which makes it a single-use part.

Reinforced ARP bolts for connecting rods

Few parts of the bottom end work as hard as the rod bolt: at every revolution, it is what stops the cap from pulling away under the inertia loads of the rod and piston assembly. The original bolt is designed for stock power and is single-use.

The ARP2000 bolts in this kit take the place of the original bolts: on the original rods, whose bolts sit in blind holes, the ARP instruction sheet calls for torque tightening, as stretch measurement is not possible there. Material: ARP2000, an alloy steel developed by ARP, heat treated to 220,000 psi tensile strength, with threads rolled after heat treatment. Against classes 10.9 and 12.9 of original fasteners, between 150,800 and 176,900 psi minimum, the margin is 24 to 46%. The engine speed allowed by the ARP2000 bolts goes up to 9,500 rpm (calculated estimate).

Technical specifications

Tightening torque

Source of the torque and stretch figures: ARP 201-6305 instruction sheet, in the revision applicable at publication. The manufacturer's instruction sheet prevails in the event of any difference. Read the ARP 201-6305 instruction sheet

The ARP instruction sheet does not require a thread locker for this kit; only ARP Ultra-Torque grease is applied, on the threads as well as under the bolt head.

The ARP instructions for this kit require the big ends to be checked and resized once the fasteners are fitted: this job belongs to an equipped machine shop.

Technical guide

The torque figure given is only valid with ARP assembly grease, applied to the threads and under the head.

The ARP brand

ARP (Automotive Racing Products) came into being in the early 1970s, when Gary Holzapfel, who came from the aerospace industry, decided to tackle the engine failures caused in motorsport by inadequate fasteners. Today the brand produces thousands of part numbers in California for the cylinder head, the main bearings and the connecting rods, in materials suited to each application, with manufacturing known for its consistency.

Vehicle compatibility

OEM reference (rod bolt): 11 24 7 593 922 (M7 x 37 mm)

Why is it the most cost-effective solution?

When an engine is tuned, its connecting rods take inertia loads far above those of the standard engine, and a single bolt letting go is enough to destroy it. Reinforced, the ARP2000 bolts in this kit withstand higher engine speeds and loads and lower that risk, at a cost far below that of rebuilding the engine.

Matching connecting rod bearings

New bolts, new bearings: find below the connecting rod bearings suited to this engine.

Why not step up to forged connecting rods?

Hot forged under considerable pressure, generally from 4340 steel, a forged rod has a denser and more uniform structure than a stock rod. Against the original rod, frequently made of sintered metal and optimised for production cost, it brings about +19% yield strength, +8% tensile strength and +19 to +37% fatigue strength: enough to build a reliable high-power engine on. For your engine: