HomeResourcesConnecting Rod InstructionsConnecting Rod InstructionsImportant note-ARP highly recommend using a stretch gauge when installing rod bolts and other fasteners, where it is possible to measure the length of the fastener. It is the most accurate way of measuring preload of any bolt. When using a stretch gauge it\'s best to measure the fastener prior to starting and monitor overall length during installation. When the bolt has stretched a specified amount, the correct preload or clamping force has been applied. ARP recommend that you maintain a chart of all rod bolts and make a note of the fastener length prior to installation and after any disassembly. If there is a permanent increase of .001" or more in length, there is a deformation and the bolt should be replaced. For more information, please refer to ARP website: www.arp-bolts.comARP ROD BOLT INSTALLATION PROCEDURES1Clean the mating surfaces, thread in bolt hole and bolt head loading surface on cap2Match the numbers of cap and beam3Using strength gauge check the original bolt length4Lubricate bolt thread and under-head chamfer5Install bolts to end of thread by hand6Tighten bolts with torque wrench in 2 steps, refer to the recommended torque7Using the strength gauge check the length of bolt again, make sure the stretch is correct. If not, tight or loose the bolt to correct the stretchARP ROD BOLT STRETCH & RECOMMENDED TORQUE BOLT DIA Material U.H.L BOLT STRETCH TORQUE SPECS 5/16" ARP 2000 - 220,000 psi 1.500" .0050" to .0055" 25-28 ft/lbs 3/8" ARP 2000 - 220,000 psi 1.600" .0055" to .0060" 45-50 ft/lbs 3/8" ARP625+ - 280,000 psi 1.600" .0063" to .0067" 50-55 ft/lbs 7/16" ARP 2000 - 220,000 psi 1.600" .0055" to .0060" 65-70 ft/lbs 7/16" ARP 2000 - 220,000 psi 1.800" .0060" to .0065" 70-75 ft/lbs Clearances listed below are a general guideline and may vary according to the application and engine builder preference: ROD BEARINGS .002" to .003" SIDE CLEARANCE .015” to .025” PISTON PIN .0001" to .0015"
