The 151ci Kit from Leading Edge V-Twin is unlike anything the custom motorcycle industry has seen before. This motor has a 4.310 bore on a 5.180 stroke for a total displacement of a whopping 151.14 cubic inches.

This performance kit increases your 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 provides both consistent and dependable naturally-aspirated horsepower as well as massive amounts of torque. The engine cases have to be thoroughly and expertly machined for this version of the big-inch kit to be used.

The Leading Edge 151 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, and 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 151ci 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 151ci kit.

Pistons Our pistons are made of our proprietary design by CP Carillo. They are balanced and come with Total Seal rings.

Rods Our balanced rods are also made of our proprietary design by CP Carillo. Due to our design these rods are far stronger than stock while being significantly lighter

Cylinders Our cylinders are made in the USA from aerospace-grade billet aluminum. Our radically different fin design results in far more efficient air cooling. Inside the cylinders reside aircraft-grade steel sleeves coated with our proprietary mix of Nikasil nickel/carbide/silicon plating.

Crank Our Flywheels are static balanced, assembled and then dynamically balanced allowing us to eliminate the stock counterbalancing system. We also use a proprietary crank pin that does not allow the flywheels to scissor. This design is so inherently strong that it eliminates any need to weld the flywheels.

The 151ci Kit can only be ordered as a kit where your complete bike is sent to us in Phoenix, Arizona and we do the installation and dyno tuning free of charge.

Air Cleaner

Cam Plate & Oil Pump

Clutch

Cylinder Head Porting

Exhaust

Leading Edge 125 Kit

Leading Edge 129 Kit

Leading Edge 151 Kit