American Motorcycle Dealer AMD 226 May 2018 | Page 33

R&R CYCLES Manchester, New Hampshire, USA Tel: [phone] [email protected] www.rrcycles.com R&R crate motors use a set of Harley- Davidson cases meant for use with 110 inch engines. Because the crate motors are either 124 or 131 cubic inches, the cases have to be opened up on the CNC to accept the larger cylinder spigot. Big cubes from R&R - when too much is almost enough When R&R decided to build one of the biggest V-twins available for the street, they started with a clean sheet of paper and four really big chunks of aluminum. The two billets that form the cases weigh 122 and 70 pounds, while the cylinders weight in at 20 pounds each, as delivered to the shop. The CNCs are called upon to do a variety of tasks, like boring a new R&R aluminum cylinder with iron liner. Like the rest of the crankshaft assembly, the pinion shafts are machined in house on one of the CNCs. After time on the CNC machines, the cases become home to a one-off R&R flywheel assembly with 4.625 inches of stroke. The cylinders, on the other hand, make a detour to a specialist shop after the initial machining. After the iron liner is pressed into place, the cylinders make a trip back to R&R where they’re bored and honed to accommodate a pair of 4.60-inch pistons. The heads too are essentially one-off pieces cut from billet aluminum, designed to run a 2.15 inch intake valve and a 1.75 inch exhaust valve. Operating the valves is an off-the-shelf cam - or cams - as the engines can be built as an Evo or Twin Cam. Customers can choose more than just the cam drive - compression ratio, cam specs, and the overall goals for the motor, the customer can help design the whole package. Typical output runs from 160 to 180 ft. lbs. of torque and 150 to 175 horses, depending on all the items mentioned above, and the exhaust the customer chooses. So, if you’re a big believer in the idea that too much is almost enough, just give R&R a call. A finished crankshaft set-up in the dynamic balancer. Note how the area where the pin comes through the flywheel has been ground - to smooth out the area where the pin was welded to the flywheel. Available in various strokes for both Evo and Twin Cam style motors, R&R flywheel assemblies combine smooth operation with bullet-proof durability. www.AMDchampionship.com AMERICAN MOTORCYCLE DEALER - MAY 2018 33