ARC stock length billet rod with bearing inserts for the Harbor Freight Predator 420cc engine. Fits both the Hemi and non-Hemi versions. 3.308" center-to-center for a 1.188" rod journal and .709" wrist pin. Stock OEM length for use with the stock crankshaft and stock style (dished or flat top) piston in modified engines. Built from 7075-T651 aircraft grade aluminum. Uses ARC's custom manufactured bearing inserts and ARP rod bolts manufactured specifically for ARC. ARC has the only forced oiling scoop dipper rods available for these engines providing superior lubrication at the bearing journal.
Rod includes bolts & bearings.
Rod bolt torque: 170 in/lbs lubricated
Installation Instructions:
To install your ARC rod you will need a 12 point 1/4" socket and a QUALITY inch pound torque wrench. You will need an outside micrometer, dial bore gauge or plasti gauge, and oil.
Measure the crank pin diameter with the outside mic, it should measure 1.188" +/-.0005". Measure in several spots to insure roundness. If out of round more than .0005" it probably should be replaced. The crank pin finish should be smooth to the touch.
When disassembling the rod notice on the side of the rod with the part number there are two dots next to the separation point of the beam and cap. These dots help to re-orientate the cap and beam when assembled. The side of the rod with the part number engraved will always face the side cover side.
Make sure the bearing and rod serrations are clean and install the bearings. Lubricate the rod bolt threads and hand tighten the bolts. Using the torque wrench tighten the bolts to 60" lbs. Alternate each side to increase the torque by 20" lbs at a time until you reach 150"lbs. Then loosen the bolts and repeat the torque process. this helps seat the rod bearing especially on a new rod. Measure the bore with your dial bore gauge opposite the parting lines. If using plasti gauge you will have to install the rod on the crank and use in accordance the plasti gauge instructions.
The rod bore should measure 1.191 +/.0005". With plasti gauge you are looking for about .003" clearance. From .0025-.0035" clearance is acceptable. Anything outside that dimension please call 800-521-3560 for recommendation.
Once clearance is set apply oil to rod, crank, and wrist pin and install this time torque to 170"lbs.
Improperly torquing rod bolts is one of the most common causes of rod failure.
Refer to instructions shipped with all rods and the video below for more detailed instructions.
