Harley-Davidson TRIKE FREEWHEELER Big Bore Kits

Genuine Harley-Davidson

3-7/8" Standard Bore. When combined with stock cylinder heads, these forged 3-7/8" pistons boost the compression ratio of your 3-7/8" big bore cylinder set-up. The combination results in a compression ratio of 10.5:1. Piston skirts feature a unique black coating for improved wear-resistance, better fit and reduced noise. These pistons include Titanium SST rings to withstand the stresses seen in racing. Complete kit includes pistons, rings, wrist pins and clips.

Genuine Harley-Davidson

When it comes to increasing engine power, there is no substitute for more cubic inches. With efficient filling of the air/fuel mixture, the bigger the displacement, the more power your engine can produce. In the past, the only way to increase the bore of your 96 or 103 cubic inch Twin Cam V-Twin motor was to tear down the motor and re-bore the engine cases to fit larger bore cylinder spigots. It was a labor-intensive and expensive process. Now, you can take your 96 or 103 cubic inch motor to a full 110 cubic inches without removing the engine from the chassis. The Screamin' Eagle team has engineered a 4" Big Bore Cylinder and Piston package that increase the internal bore from 3-7/8" to 4", without increasing the outside diameter of the cylinder spigot. The cylinder slips into the existing case bore without modification. This kit will add a whopping 7 cubic inches of displacement for more torque throughout the RPM range. The kit includes front and rear cylinders, system-matched pistons with rings and breathers.

Genuine Harley-Davidson

This multi-layered head gasket provides improved sealing for 3-7/8" Big Bore high performance engines. Sold in pairs.

Genuine Harley-Davidson

The most advanced Twin Cam performance cylinder head design available. Screamin' Eagle CNC Ported Maximum Velocity Area (MVA) cylinder heads create power across the entire RPM range by maximizing velocity through the intake ports. Increased air speed velocity through the ports is achieved by "right sizing" port volume at 98cc, lowering the port roof, and by precision-machining the shape of the port to complement the giant 2.120" intake valves. Screamin' Eagle CNC-Ported MVA Cylinder Heads conquer a unique engineering challenge, and provide the highest possible torque and acceleration at any RPM. MVA Heads will boost the punch of a 103" engine. When paired with high lift cams, MVA Heads can give a 110" or 113" motor everything it needs to achieve new levels of performance. Countless hours of dyno testing resulted in a 95cc combustion chamber that performs in perfect balance with the port size and shape, and reduced detonation. MVA Heads feature Screamin' Eagle Race Springs that permit the use of high lift cams (up to.660"), and are machined to accept automatic compression releases (sold separately) for easier starting. MVA Heads are manufactured and assembled at Harley-Davidson's world class engine factory in Milwaukee, ensuring every set is made to exact tolerances.

Genuine Harley-Davidson

This kit was developed for the budget minded rider that wants to experience crisp throttle response and acceleration they can feel at slower speeds. The 5% increase in torque can be felt immediately off the line and continues to build by up to a 14% increase @ 4500 RPM - the ideal power band for passing slow moving vehicles. Delivers enhanced torque and horsepower in the low to mid RPM range. Produces passing power without a downshift or high revs. Minimally invasive, only requiring opening of the cam chest. Retains Original Equipment Factory Warranty. 50-State U.S. EPA compliant.