Free Shipping with $50 Purchase + Free Returns
  • New Arrival

Screamin' Eagle 4" Big Bore Bolt-On Cylinder and Piston Kit

Part Number 92500039




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. Have you already installed a Stage III or Stage IV performance kit on your 103 Twin Cam motor? 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. All EFI models require ECM calibration (priced separately). For race application only.


Fits '07-later Twin Cam models with 4-3/8" stroke flywheel. Does not fit CVO™ 110 or models with engine cases that have been machined to accept large-bore cylinders.

Bike not listed?
Select your year and model to see all the parts that fit your bike.

  • Model
  • Warranty

    1 year limited warranty - See Customer Service section for details

Recently Viewed

    Please Hold Your Iron Horses
    Bobber Accessories

    Your Session has timed out

    You've been sitting idle, so we've ended your session to protect your personal details.

    Continue as guest Sign in


    You’ve been sitting idle, so your session will expire in

    Would you like to remain signed in and continue shopping?

    Yes, keep me signed in No, sign me out

    Prices listed are generally the Manufacturer's Suggested Retail Price (MSRP), excluding taxes and shipping. Prices at local dealerships may vary. All online orders will be fulfilled and shipped by
    Harley-Davidson Motor Company as the agent for the Selling Dealer.