5-Ball Racing 2012: Chapter 6

In the last segment, we encountered the privilege of working with Branch O’Keefe, the former Branch Flowmetrics masterminds to make my 96-inch Twin Cam head flow as if they were built for the gods.

While we rebuilt the heads at Branch O’Keefe, the crew at Hardtailz shipped the worn out twin cam cases to Randy at Hyperformance for upgrades, Timken bearings are a must for big inch power plants.

With well over 3,500 hours running time at 50 mph average my 2004 Twin cam Dyna rolled over 170,000 miles, the factory cases were well seasoned and damn near wasted. The hard working crew at Hardtailz in San Jose disassembled the twin cam engine, packed and shipped the pieces to Randy Torgeson at Hyperformance in Pleasant hills, Iowa for scrutinizing.

Hyperformance CNC Machine shop is a division of Hyperformance Incorporated, experts for over 20 years in producing big bore cylinder kits for V-Twin motorcycles. Their custom CNC Machine division was established to offer companies and individuals fast, reliable and accurate machining services. Their Machine Shop is equipped with two computerized high-speed CNC vertical machine centers and two manual metal turning lathes. Hyperformance CNC Machining also offers complete ancillary services and can sleeve, bush and precision hone virtually any reconstruct project.

Whether your requirements call for fast turn-around on standard parts or the production of unique prototype parts, or rebuilt parts, HYPERFORMANCE can make it happen. Highly skilled CNC specialist not only offer precision machining services but can also fit and assemble parts to a finished state as well.

HYPERFORMANCE offers free pick up and delivery to all customers within a 100-mile radius of Des Moines. For a quick quote or to discuss your future machining needs, call me, Randy Torgeson, at 515-266-6381.

“Your cases can and will be saved and rebuilt to better than stock specifications,” Randy said.

The head bolts were tested and measured for stretch, thread damage, and case fitment, all were within specs as well as being solidly anchored.

My next issue was the Timken bearing area. The race for the Timken bearing was loose and digging into the case. Randy set up the left half of the case on his mill, re-machining the damaged area. A precision-machined steel bushing was pressed into place then securely anchored with 4 machine screws. Our rebuilt cases are expected to last another 3 or 4,000 hours with timely oil and filter changes.

With the cases rebuilt and looking better than new, they were boxed and shipped to Bennett’s Performance in Signal Hill for the final build.

Next, we needed to gather all the perfect products to build a finely balanced, long-distance, streetwise Twin Cam for my hard road future.

With a pile of clean, new and a few used parts (pushrod tubes) on the table and a slight break in the action. Eric cleaned and organized the engine room bench Friday afternoon after a hard days work and dove in headfirst.

After cleaning the cases and staging the parts in an organized manner Eric started the assembly process starting with a brand new 4-inch Darkhorse lower end.

Hoban Brothers offers complete machine shop services and lower end rebuilding under the DarkHorse Crankworks name, along with standard service, parts, accessories, and consignment sales of Harley-Davidson and Buell motorcycles. They have very knowledgeable and experienced factory trained technicians who service all Harley-Davidson models from early to late. They have a trusted reputation for excellence when it comes to performance modifications, motor building and fuel injection tuning.

Hoban Brothers started in 1980 and remains a family owned business. Located in Osman, which is a little town in East Central Wisconsin along Lake Michigan in between Manitowoc and Sheboygan.

Their DarkHorse proprietary process to balance, build or rebuild crank assemblies is the key to a successful lower end, the heart and soul of any motor. They have an outstanding reputation for precision flywheel work, engine case machining and Timken bearing upgrades. They have over 30 years of experience building engines and winning National Championships in professional motorcycle racing. Before we bought a junk new lower end, we discovered unmatched quality workmanship and balancing through DarkHorse.

Fresh out of the box we decided to double check run-out. Yeah, never know how many times the UPS drivers tossed the box across the loading dock on the 5-day, multiple truck journey. Run-out was near perfect, the H-beam rods appeared close-to-bullet-proof? Eric installed the lower end applied case sealer and buttoned up the cases. Every time a bolt was torqued to specs, we spun the lower end checking for tight spots that never appeared. The Darkhorse lower end was smooth as butter on a hot day in July. We called it a night and hauled ass in the dark.

Next on the list, we’ll installed the Fueling Reaper Series .574 lift chain drive cams, supported by a H-D Billet support plate/oil pump.

This kit updates the cam chain tensioner of any Twin Cam 88 engine to the latest design, as featured on the Twin Cam 96 engine. The billet cam support plate has been designed to allow the installation of the Twin Cam 96 hydraulic cam chain tensioner to Twin Cam 88-equipped models. These Hydraulic Cam Chain Tensioners will significantly outlast the spring loaded tensioners, and are an ideal addition to an engine modified for improved performance.

In addition, ’02-’06 models utilize a Twin Cam 96 single row front roller chain and sprocket (included in kit). ’99-’01 models use Original Equipment front silent chain and sprocket to retain the cam position sensor function. The kit includes an improved Screamin’ Eagle High-Flow Oil Pump that provides increased oil pressure at high-operating temperatures. This kit increases the oil supply by 23% and scavenging by 50% when compared to the ’99-’05 Original Equipment oil pump, and reduces operating temperature of bearings to improve bearing life.

Eric followed with the installation of the 97-inch CCI (RevTech) cylinder and piston kit. The RevTech 97-inch and 106 Big Bore Kits with Forge Pistons were new to the CCI line-up when we ordered them. It comes with 4-inch bore cylinders with forged and coated KB pistons, which will increase the displacement of our 88-inc engine to an easy 97-inches.

Then we touched off the formula with a set of flowed Branch/O’Keefe flowed heads, and Crane Roller Rockers. Stock Ratio Bushing Roller Tip Rocker Arms
Stock ratio roller tip rocker arms fit 1984 – up Harley-Davidson Evolution, Twin Cam 88, and Twin Cam 96 big twin engines and 1986 – up Sportster and Buell models.

Crane roller tip rocker arms have a bushing fulcrum for longterm performance and reliability. These rocker arms use the original equipment rocker arm shafts. Made from 8620 alloy steel, precision forged for greater strength, truer rocker arm ratio, and improved rocker geometry. Also their exclusive oil metering system fully lubricates the fulcrum and roller tip for cooler, smoother operation. These rocker arms fit with no machining, making them easy to install.

Eric wrapped up the build with Fueling Race Series lifters, and pushrods. We will bring you more info on the Rev Tech top end build, with the help of Brad Beach at CCI, and additional info on Fueling performance parts, in the very near future.

Haul Ass!
Ride for your Life!
–Ray c wheeler
Performance Editor
wheeler@bikernet.com

5-Ball Bonneville 97-Inch Twin Cam Sources

Bennett’s Performance