Reinforced ARP bolts for OEM rods VW AUDI SEAT FORD VR6 AAA ABV AMY AQP AUE BDE AYL BFH BJS BML BUB CBRA BHE BPF BMJ BDB

The Volkswagen VR6 engines concerned

The VR6 is Volkswagen's compact six-cylinder, a very narrow V under a single cylinder head: the 2.8-litre of 163 to 174 hp (AAA, AMY, 2,792 cm³, 81 mm bore, 90.3 mm stroke), the 2.9-litre Syncro of 184 to 190 hp (ABV), the 24-valve 2.8-litre of 204 hp (AQP, AUE, BDE, AYL) and the 3.2-litre R32 of 241 to 250 hp (BFH, BJS, BML, BUB, CBRA, BHE, BPF, BMJ, BDB, 3,189 cm³, 84 mm bore, 95.9 mm stroke). It sits under the Volkswagen Golf III, Golf IV and Golf V R32, Corrado, Passat, Vento, Bora, Sharan, Eos and Jetta, the Seat Alhambra and Leon, the Audi A3 and TT and the Ford Galaxy.

This ARP kit replaces, on every rod, the original rod bolt of these engines: a single-use bolt whose reference Volkswagen does not publish.

Reinforced ARP bolts for connecting rods

At every revolution, the rod bolt takes the pull of the rod and piston assembly, which tries to force the cap away through inertia. As original equipment, it is sized for stock power and is replaced at every strip-down.

The ARP2000 bolts in this kit are best tightened by stretch, read with a gauge, ARP giving 54.2 Nm for those who do not have one. 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%.

Technical specifications

The ARP instruction sheet specifies fitting without a washer, with a sufficient chamfer at the rod cap bolt hole to clear the radius under the head.

Tightening torque and stretch

For this part, ARP favours tightening to a measured stretch, the key to an exact preload; torque is given only when no gauge is available. The figures in the table assume ARP lubricant.

The values above come from the ARP 204-6006 instruction sheet applicable at the date of publication; it is authoritative in the event of any difference. Read the ARP 204-6006 instruction sheet

Assembly is done without thread locker, as the ARP instruction sheet calls for none: ARP Ultra-Torque grease is applied to the threads and under the head of each bolt.

Once the fasteners are fitted, the ARP instructions call for the big ends to be checked and resized by a machine shop.

Measuring bolt stretch

Tightening to stretch means setting the preload on how much the bolt actually stretches, rather than on a torque affected by friction. With the bolt fitted, the dial gauge is placed on both its ends and the bolt is tightened until the stretch given in the table is read. It is the safest method on a highly tuned engine.

Technical guide

Torque and stretch figures are 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

Why is it the most cost-effective solution?

On a VR6 pushed on revs or boost, the rod bolt takes tensile loads that climb with every extra turn of the crank, and a single bolt letting go costs the rod, the piston and the block. A set of ARP2000 bolts covers that risk for a fraction of the price of a bottom end to rebuild.

Matching connecting rod bearings

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