Reinforced ARP bolts and nuts for OEM rods NISSAN SR20DE SR20DET

The Nissan SR20DE and SR20DET engines concerned

This kit is intended for the Nissan SR20DE and SR20DET engines, four-cylinder units of 2.0 litres with twin overhead camshafts and 16 valves, naturally aspirated or turbocharged: Silvia and 200SX S13 to S15, Pulsar GTI-R, Bluebird, Primera, Sentra SE-R and Almera GTi.

It replaces the original rod bolt with an ARP 8740 bolt of 11/32 in diameter, pressed into the connecting rod and closed with a nut.

Reinforced ARP bolts and nuts for connecting rods

At every engine revolution, the rod and piston assembly pulls on the rod cap, and only its bolts hold it against these inertia loads. The original ones are intended for stock power.

Each ARP bolt is pressed into the stock SR20 rod and takes its nut; the ARP instructions call for tightening up to the specified stretch, measured with the gauge, and give a substitute torque for those who do not own one. Material: 8740, a chrome-moly steel heat treated by ARP to 180,000 psi tensile strength, with threads rolled after heat treatment. Factory-fitted fasteners usually fall into classes 10.9 and 12.9, between 150,800 and 176,900 psi minimum. In 8740, these bolts are rated for 9,000 rpm at most (calculated estimate).

Technical specifications

One point of the ARP instructions to observe before pressing the bolts in: the rod bore must have a sufficient chamfer at its top so as not to interfere with the radius under the head.

Tightening torque and stretch

ARP recommends tightening to a measured stretch, which gives a more accurate preload than torque alone, given as a fallback. Torque and stretch figures assume ARP lubricant.

Source of the torque and stretch figures: ARP 202-6005 instruction sheet, in the revision applicable at publication. The manufacturer's instruction sheet prevails in the event of any difference. Read the ARP 202-6005 instruction sheet

No thread locker is called for by the ARP instruction sheet for this kit: the bolts are fitted with ARP Ultra-Torque grease, on their threads and on the bearing face of the nuts.

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.

Measuring bolt stretch

Stretch measurement supplements torque tightening and gives the most accurate preload. It is done with the bolt in place: the gauge, fitted with a dial indicator, bears on both ends of the bolt and shows the stretch achieved, to be brought to the value in the table above. This avoids the variations caused by friction, which matters on a highly stressed engine.

Technical guide

All the torque and stretch values on this page assume ARP assembly grease on the bolt threads and on the bearing face of the nuts; engine oil does not replace it.

The ARP brand

An engineer with an aerospace background, Gary Holzapfel launched ARP (Automotive Racing Products) in the early 1970s with one goal: to eliminate engine failures caused by weak fasteners in racing. ARP designs and manufactures thousands of part numbers in California, cylinder head, main and rod bolts, in several materials depending on the use, and has become known for the consistency of its manufacturing.

Vehicle compatibility

Why is it the most cost-effective solution?

An SR20DET from a Silvia or 200SX running more boost, or an SR20DE pushed to higher revs, loads its rod bolts well beyond the use planned in standard form, and a bolt that lets go takes the rod, the piston and the block with it. The ARP 8740 kit remains a modest outlay compared with a full engine rebuild.

Matching connecting rod bearings

To complete the bottom-end rebuild, we offer the connecting rod bearings intended for this engine.