Leading A-Series engine specialist since 1981
ARP conrod bolt kits are sold in engine sets for Cooper S, A-plus or 998 conrods. These are a direct replacement for the standard fixings.
Upgrading the standard conrod bolts is essential for any performance engine build, as these are far more resistant to stretch than the standard items. We would recommend these for all engine rebuilds.
Beware of poor quality imitations available online - if the price seems to good to be true, they are unlikely to be genuine ARP bolts.
Please see the additional information tab for further specifications.
These bolts are machined from ARP2000, an alloy steel with a tensile strength of 220,000 PSI. ARP2000 is used widely in motorsport applications as an upgrade from 8740 chrome moly in both steel and aluminium rods. Stress corrosion and hydrogen embrittlement are typically not a problem, providing care is taken during installation.
As long as the fasteners have been installed and torqued correctly, and show no visible signs of damage, they can be re-used. If they show any signs of thread galling or corrosion, they should be replaced. If the bolts have stretched by 0.001” or longer, you should replace them immediately. We stock the ARP rod bolt stretch gauge for this purpose.
ARP recommends the 3/8" fixings should be torqued to 55lb.ft, but we would advise 42lb.ft. The 11/32" fixings should be torqued to 35lb.ft. Preferably these should all be checked using an ARP rod bolt stretch gauge and stretched to 0.0065"-0.0070".