Reinforced ARP bolts for OEM rods TOYOTA LOTUS 2ZZ-GE

The engine concerned

This kit is intended for the Toyota 2ZZ-GE 1.8-litre 16-valve engine, fitted to the Celica, the Corolla (T-Sport and Compressor), the Matrix XRS, the Pontiac Vibe GT, and to the Lotus Elise and Exige.

This kit replaces the original rod bolt of the 2ZZ-GE with an ARP bolt with an M10 thread and a 12-point head, made from ARP2000.

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.

This kit brings together ARP2000 connecting rod bolts that the ARP instructions have you tighten by stretch with a gauge, torque tightening being the fallback provided when no gauge is available. 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%. In ARP2000, these bolts are rated for 11,750 rpm at most (calculated estimate).

Technical specifications

Tightening torque and stretch

For this part, ARP favours stretch measurement in addition to torque, the key to an exact preload. The figures in the table assume ARP lubricant.

Source of the torque and stretch figures: ARP 203-6301 instruction sheet, in the revision applicable at publication. The manufacturer's instruction sheet prevails in the event of any difference. Read the ARP 203-6301 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 the threads and under the head.

According to the ARP instructions, the big ends must be checked and resized with the fasteners in place; plan a visit to 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

Tightening is done with ARP assembly grease, on the threads and under the head: the torque and stretch figures in the table were established with 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?

On a tuned 2ZZ-GE, each connecting rod takes inertia loads at high revs that are far above those of a standard engine, and the failure of a single bolt is enough to destroy the engine. Reinforced ARP2000 bolts secure this precise point for an outlay out of all proportion to that of rebuilding an engine.

Matching connecting rod bearings

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