Reinforced ARP cylinder head studs Audi Volkswagen EA113 EA888

The engines concerned

The Volkswagen Group 2.0 TFSI and TSI engines, EA113 then EA888 (generations 1 to 4), are 2.0-litre turbocharged inline four-cylinders with an original bore of 82.5 mm: the EA113 was built from 2004 to 2010, the EA888 from 2008 onwards. They power the Audi A3, S3, A4, TT, TTS and S1, the Volkswagen Golf GTI and R, Scirocco and Polo R WRC, the Seat Leon Cupra, the Cupra Leon and the KTM X-Bow, among others. ARP offers the 204-4302 stud kit for them, in ARP2000, and also lists it for the 1.8 TSI EA888.

Reinforced ARP cylinder head studs

The job of the head fasteners is to keep the cylinder head locked to the block despite the pressure inside the combustion chambers. They keep the gasket compressed; as soon as their clamping force drops, leaks appear between head and block.

The ARP 204-4302 kit contains 10 studs supplied with their washers and 12-point nuts, with an M10 x 1.5 thread, in ARP2000.

According to the instruction sheet, the studs are screwed into the block by hand; the cylinder head is fitted next, then lubricated washers and nuts are tightened in three equal passes, in the manufacturer's tightening sequence.

Developed by ARP, ARP2000 alloy steel is heat treated to 220,000 psi tensile strength, and its threads are rolled once the treatment is done. Compared with the 10.9 and 12.9 classes of standard fasteners, between 150,800 and 176,900 psi minimum tensile strength, the gap reaches 24 to 46 %.

In M10 x 1.5, the ARP2000 studs hold up to 600 hp on this four-cylinder engine (calculated estimate).

Technical specifications

Tightening torque

The studs are fitted into the block by hand, without a torque wrench. For a permanent installation, the instruction sheet accepts thread locker, with tightening to be completed before it sets.

The instruction sheet asks you to clean the block threads and, if needed, to run the ARP 912-0003 tap (M10 x 1.5) through them.

ARP thread sealer is only used if the studs open into a water jacket.

Final tightening is done in three successive stages, following the manufacturer's tightening sequence; these torque figures only hold with ARP assembly lubricant on the threads and under the nuts.

The instruction sheet also calls for ARP lubricant on the washers.

Values taken from ARP instruction sheet 204-4302, in the revision current on the date of publication. In the event of any discrepancy, the official instruction sheet prevails; it also details the full procedure and the tightening sequence. Read the ARP 204-4302 instruction sheet

Technical guide

To obtain the intended preload, ARP assembly grease must be present on the threads and under the nuts: the torque figures in the table are established with it.

The ARP brand

Founded in the early 1970s by Gary Holzapfel, who came from the aerospace industry, ARP (Automotive Racing Products) set itself the mission of eliminating engine failures caused by inadequate fasteners in competition. Its thousands of parts are designed and produced in California, in several material grades depending on the application.

Advantages over the original bolts

Criterion	Original head bolts	ARP2000 studs
Block thread	Stressed at every tightening	Spared (studs screwed in by hand)

When studs become necessary

Standard fasteners remain suitable as long as the engine keeps its original combustion pressure. They reach their limits in the following cases:

• Power raised on a 2.0 TFSI or TSI (engine map, turbo, boost pressure)
• Compression ratio raised for more power
• Reinforced MLS head gasket, which requires a high and even preload
• Cylinder head that has already lifted or gasket that has already leaked
• Racing or track use, with repeated heat-ups and frequent teardowns

Vehicle compatibility

Why is it the most cost-effective solution?

The original head bolts are sized for stock power: the more boost pressure rises, the harder the gasket and the fasteners work. ARP2000 studs carry a clearly higher clamp load and keep the gasket pressed down; removing the cylinder head a second time, with a new gasket and labour, costs far more than the kit.

Consider a reinforced head gasket

Reinforced fasteners are only fully worthwhile with a head gasket able to resist the same pressure. We offer the following part for this engine: