ARP 8740 Chromoly Main Stud Kit | 4A-GE (AE86/AW11)

ARP 8740 Chromoly 4A-GE Main Stud Kit

For Toyota 4A-GE DOHC 16V Engines – AE86 Corolla & AW11 MR2

Overview

The ARP Main Stud Kit is a high-strength bottom-end fastener upgrade for Toyota 1.6L 4A-GE DOHC 16-valve engines. It replaces the factory main-cap bolts with precision-manufactured studs designed to provide more consistent main-bearing-cap clamping during engine assembly.

Main studs are particularly useful in performance, high-RPM, and rebuilt 4A-GE engines where maintaining accurate crankshaft main-cap alignment is important. Unlike a conventional bolt that rotates into the block while being tightened, a stud remains stationary while the nut is torqued, helping provide more consistent fastener loading.

The studs are manufactured from heat-treated 8740 chromoly steel with a black oxide finish and a tensile-strength rating of approximately 190,000 psi. Hardened washers and high-strength hex nuts are included to complete the main-cap fastening system.

Key Features

• Designed for Toyota 1.6L 4A-GE DOHC 16V engines
• Performance replacement for factory main-cap bolts
• 8740 chromoly steel construction
• Approximately 190,000 psi tensile-strength rating
• Heat-treated fastener construction
• Precision thread-rolled stud design
• Black oxide finish
• Helps reduce main-cap walk and fretting
• Provides consistent main-bearing-cap clamping
• Includes hardened parallel-ground washers and high-strength nuts

Main Stud Design

The stud-style fastening system separates block-thread engagement from final clamping torque. Each stud threads into the engine block first, while the main cap is secured by tightening the nut over the washer.

This arrangement reduces the twisting load placed on the fastener during final tightening and helps maintain more consistent clamping across the main-bearing caps. It is well suited to 4A-GE engine rebuilds, naturally aspirated performance builds, and other applications where increased bottom-end fastener strength is desired.

Vehicle Fitment

Toyota Corolla Levin AE86

• 1983–1987 Toyota Corolla Levin – AE86 – 1.6L 4A-GE / 4A-GEU DOHC 16V

Toyota Sprinter Trueno AE86

• 1983–1987 Toyota Sprinter Trueno – AE86 – 1.6L 4A-GE / 4A-GEU DOHC 16V

Toyota Corolla Sport GT-S AE86

• 1985–1987 Toyota Corolla Sport GT-S –  AE86 – 1.6L 4A-GE DOHC 16V

Toyota MR2 AW11

• 1984–1989 Toyota MR2 – AW11 – 1.6L 4A-GE DOHC 16V

Fitment Notes

• For Toyota 4A-GE DOHC 16-valve engines
• Does not fit the factory AE86 SR5 4A-C SOHC engine
• AE86 SR5 fitment requires a properly completed 4A-GE engine conversion
• Designed for a 2-bolt main-cap configuration
• Not designed for windage-tray mounting
• Engine disassembly is required for main-stud installation
• Main-bearing clearances and crankshaft alignment should be checked during engine assembly
• Follow the supplied fastener installation and torque procedure
• Professional engine assembly or machine-shop inspection is recommended for performance engine builds

Product Specifications

Brand: ARP
Product Type: Engine Main Stud Kit
Engine Family: Toyota 4A-GE
Engine Displacement: 1.6L
Cylinder Head Configuration: DOHC 16V
Main Configuration: 2-Bolt Main
Fastener Style: Stud
Nut Style: Standard Hex
Material: 8740 Chromoly Steel
Finish: Black Oxide
Tensile Strength: Approximately 190,000 psi
Washers Included: Yes
Nuts Included: Yes
Windage Tray Provision: No
Application: Crankshaft Main Bearing Cap Fastening
Manufacturer Type: Aftermarket Performance

What's Included

• ARP 4A-GE main studs
• High-strength hex fastening nuts
• Hardened parallel-ground washers