Reinforced ARP main studs for Nissan VQ35DE

The Nissan engine concerned

This kit is made for the naturally aspirated Nissan V6 of 3.5 litres, 24 valves and twin overhead camshafts (VQ35DE), fitted to the 350Z, Altima, Maxima, Murano, Pathfinder, Skyline, Stagea, Teana, Quest and Elgrand.

On the stock VQ35DE the main caps are secured with bolts; this kit replaces them with studs.

Reinforced ARP studs for main bearings

The bottom end rests on its main bearings: combustion after combustion, the loads coming from the connecting rods end up on them. Under this stress the main cap tries to move on its parting line, which eventually brinells the mating faces and distorts the bearing bore.

This kit replaces the original main cap fasteners of the VQ35DE with ARP 8740 steel studs, M10 x 1.5, and their nuts. The block threads are cleaned, then the studs are run in by hand, without a wrench. With the caps in place, threads, washers and nuts are coated with the ARP Ultra-Torque lubricant and the nuts are tightened in three equal passes, following the order recommended by the manufacturer. Because only the nut turns, the torque reading reflects the real preload better and the block thread stays intact. Material: 8740, a chrome-moly steel that ARP specifies at 190,000 psi tensile strength, with threads rolled after heat treatment. Factory-fitted fasteners usually belong to classes 10.9 and 12.9, with 150,800 to 176,900 psi minimum tensile strength. The 8740 studs in M10 x 1.5 hold up to 2,900 hp on this V6 engine (calculated estimate).

Technical specifications

Tightening torque

Fitting the studs: screwed into the block by hand, without a tightening tool. Where a permanent installation is wanted, ARP accepts a thread locker of the blue Loctite type on the block-side thread, provided the nuts are tightened before it sets; none goes on the nuts or with ARP grease.

ARP instruction sheet 202-5801 is written for the Nissan 3.5-litre VQ35 V6 with double overhead camshafts and sets the final tightening at 81 Nm.

Follow the cap tightening sequence recommended by the manufacturer when bringing the nuts up to torque; the kit's instruction sheet details each step.

With stronger fasteners, the clamping force is no longer what it was originally: the size and roundness of the main bearing bores must be checked once installation is complete, and align honed if necessary with the final fasteners and lubricant.

Values taken from the ARP 202-5801 instruction sheet in force at the date of publication; the official instruction sheet prevails should any difference appear. Read the ARP 202-5801 instruction sheet

Technical guide

All the torque values on this page assume ARP assembly grease; with engine oil they are no longer correct.

The ARP brand

ARP, short for Automotive Racing Products, was born in the early 1970s on the initiative of Gary Holzapfel, an engineer from the aerospace sector, in response to the engine failures caused in racing by inadequate fasteners. Today the brand produces thousands of part numbers in California, offered in several materials depending on the application.

Advantages over the original bolts

Criterion	Original main bolts	Reinforced ARP studs
Tightening method	Bolt screwed into the block	Nuts tightened in three equal passes
Block thread	Stressed by the rotation of the bolt	Stud run in by hand, no torque
Fitting the caps	Cap held by hand while screwing	Cap guided by the studs

When studs become necessary

• VQ35DE fitted with a turbo or supercharger
• Engine speed pushed beyond the original limit
• Bottom end opened for a full rebuild
• Main caps that move or worn block threads
• Regular sporting use, track or competition

Vehicle compatibility

Why is it the most cost-effective solution?

A VQ35DE boosted by a turbo or supercharger, or revved hard, puts the bottom end under heavy load, and the main caps are where the work happens. ARP 8740 studs clamp them with a preload well above that of the original bolts, for a modest cost compared with repairing the crankshaft and block.

Consider the crankshaft main bearings

To complete the bottom end overhaul, consider the tri-metal crankshaft main bearings suited to these engines: