Now that you've got the best looking and most technically advanced Sportster in history in your garage, NRHS wants to help make your new XL run as good as it looks with the introduction of our 1250cc bolt-on big bore kit. Filled with premium components, this kit is the perfect foundation on which to build your American hot-rod,  and best of all, no case boring is required for installation! Each of these kits includes a pair of premium quality cylinders in your choice of iron lined aluminum or all cast iron. Our testing has shown these cylinders are superior in both ring seal and longevity to any other cylinder of the same type on the market. Also included is a set of premium quality NRHS Hurricane forged pistons with tool steel wrist pins, Total Seal rings, and Cometic EST gaskets. Take your Sporty to the next level with a bolt-on big-bore kit from NRHS! 

Note:  all of our kits use the 2003 and older style cylinders. They bolt up just like the newer cylinders but the fins are slighly smaller. In our experience this does not cause any extra heat and most folks cannot tell the difference when installed.

Ordering Information

1250 Kits With NRHS Iron Lined Aluminum Cylinders (shown above)

Iron Lined Aluminum construction offers greater structural integrity with good heat dissipation and excellent ring seal.

1250 Kits With Axtell Cast Iron Cylinders (shown above)

Cast iron construction offers the ultimate in structural integrity and ring seal.  Cylinders come only in black baked finish. Fin highlighting is not available. Powder coating is available for an additional $100.00

88" BIG BORE KITS FOR THE 2004 & UP SPORTSTER

Turn your new XL into the absolute nastiest hot-rod around! These kits take your Sporty out to the maximum bore size you can get in your stock cases. Of course, this engine kit comes with the finest quality components money can buy: Kit includes Axtell iron lined aluminum,  matching forged Hurricane pistons with tool steel wrist pins, Total Seal rings, and Cometic EST gaskets! Note: case boring is required for installation.

88ci Kits With Iron Lined Aluminum Cylinders

For those who want light weight, good heat dissipation, and and more structural integrity we now offer 88" Axtell cylinders in aluminum with a cast iron sleeve.  These cylinders are built to last with heavy duty ribs in the cooling fin areas. Other powder coat colors available, please call for details.

ARE YOU READY FOR THE POWER THAT ONLY PORTED HEADS CAN PROVIDE? AN NRHS STAGE 1/2/3 BOLT-ON KIT IS THE ANSWER!

The NRHS 2004 XL Stage 1/2/3 kits are matched packages that are proven on the dyno and on the street to work exceptionally well together. Buying a matched package takes the guesswork and error out of your project!

Not seeing what you want? Give us a call! We have tremendous experience at hot-rodding and racing XL's and we'll be happy to put together a package that works for you.