The Motorcycle Industry From The Inside With Jeff G.
Article And Photos By Jeff G. Holt
Originally Published In Torque Performance Volume 1 Issue 2 – Winter 2021
Read The Whole Article On The Torque Performance Web Site
The 159ci Kit from Leading Edge V-Twin is unlike anything the custom motorcycle industry has seen before. This kit can deliver any Milwaukee Eight powered motorcycle 200+ horsepower and 210+ ft-lb of torque. This performance kit increases a Harley-Davidson M8 engine’s torque and horsepower by over 60 percent. It runs on pump gas at 11:1 compression; making it a big-inch motor upgrade that can provide both consistent and dependable naturally-aspirated horsepower as well as massive amounts of torque.
The Leading Edge 159ci kit comes complete with a balanced crank allowing the factory balancer assembly to be eliminated. The kit also comes complete with a Timken bearing conversion, proprietary H-beam rods, pistons, cylinders, a performance oil pump and cam plate, performance valve springs and tappets. Options also include your choice of a “horsepower” or “torque” style cam to fit your personal taste and riding style.
Included items in the 159ci kit are Flywheel assembly, cylinders, pistons, Timken bearing conversion, roller bearing on pinion side, cam bearing, choice of cam, lifters, pushrods, piston jet block off plate kit, and all the necessary gaskets and seals.
Details of what’s in the LE 159ci kit.
Leading Edge’s balanced rods are also made of the brand’s proprietary design in the USA. Due to their inherent design these rods are far stronger than stock and are significantly lighter.
The custom-designed 11:1 compression ratio pistons are specially-dished to offer the most performance. The Leading Edge pistons also feature valve reliefs and are forged and machined right here in the USA. They are balanced and come with Total Seal rings.
The look of the Leading Edge’s cylinders are what has set the 125, 129, 131, and 159ci kits apart from the rest of the competition. But the beauty isn’t only skin deep. LE’s cylinders are made in the USA from aerospace-grade billet aluminum. The radically different fin design results in far more efficient air cooling. A traditional fin design dissipates heat that is then pushed away as the air passes. This “grooved and faceted” design turns the cylinder body into an active cooling system, which reduces temperatures by over 20-percent. Inside the cylinders reside aircraft-grade Ductile Iron sleeve that is centrifugally forged right here in the United States.
The LE 159ci Flywheels are 5 inch stroke. They are static balanced, assembled and then dynamically balanced allowing Leading Edge to eliminate the stock counterbalancing system.
There are many cam choices from Leading Edge. There is a mild torque cam as well as a mild horsepower cam. For optimal performance LE has an aggressive torque cam along with an aggressive horsepower cam. Each of these cam choices are key to the various LE 159ci characteristics and horsepower/torque.
Leading Edge uses precision-machined tappets that have been specifically designed to work well with each of our high-performing cam grinds. Our hydraulic roller design also optimizes oil flow to the top end of the engine.
Adjustable Push Rods
LE’s adjustable tapered push rods are made from Chromoly. They are proprietarily designed to be extremely rigid while also being very lightweight.
With all of their high-horsepower engines Leading Edge upgrades all oil pumps and cam plates to the S&S pump and plate. The S&S pump employs a dual scavenging system, that has a dedicated set of return gearmotors for the crank case, and one for the cam chest. This design maintains proper oil levels in both of those chambers minimizing loss of power from excessive fluid being present. This in conjunction with our proprietary cylinder design makes the oil temperatures drop 15-20% in the oil tank.
This engine build is not an easy one. This is why Danny Wilson aka Motorwitch, who is the creator of the kit, personally hand builds every single 159ci engine himself in Phoenix, Arizona. The reason behind this is twofold; Danny is a perfectionist, and the engine cases have to be thoroughly and expertly machined for this version of the big-inch kit to be used correctly. “Many people have asked if I can just ship them the parts so they can build their own engine with Leading Edge parts, but at this point, with the brand, I am more comfortable with doing the work myself so I know it’s right and at a place where each engine can be expertly assembled, broken in, and properly Dyno tuned.” Stated Danny.
If this is just not feasible for you and your situation, Leading Edge also offers turn-key 159ci crate engines for Bagger or Softail chassis that can be custom built and delivered world-wide via freight. Leading Edge also sells 125ci, 129ci, and 131ci kits that can be shipped and installed worldwide.
For more info on Leading Edge’s technology and products, hit up www.leadingedge.com