Converting your 883 Sportster to a 1200 or better yet a 1250 is one of the best performance investments you can make. But to do it successfully, you need high quality parts and services. NRHS has what you need!

Precision Boring and Honing of Your Stock 883 Cylinders

Save money and get the best possible ring seal and engine life by having your stock 883 cylinders precision bored and honed by NRHS. We bore your cylinders using a state-of-the-art CNC machine that not only bores them straight, but it squares the bore up to the case deck surface and precisely centers the bore to specifications. A special double cutter boring head is used to eliminate deflection induced distortions common with typical boring machines, and coolant is directed into the bore during the operation to ensure thermal stability for the straightest bore possible. Torque plates are used of course. We have found this boring equipment and procedure to produce the highest quality bore job possible.

Once bored, your cylinders are then precision honed, again with torque plates attached. During this procedure your pistons are custom fitted to the cylinders, providing a precise cylinder wall clearance that minimizes noise and enhances both ring seal and longevity. This level of precision is simply not achievable by slapping pistons into off-the-shelf cylinders. For a graphic example of this, click here.

Street Performance 883 to 1212 Conversion Package - from $524.95

This kit bundles the premium quality NRHS 883 to 1200 conversion parts and services into one convenient package. You get:   

   - Precision boring and honing of your 883 cylinders with torque plates

   - One set of premium Hurricane reverse-dome conversion pistons

      these provide a 10:1 compression ratio with your stock 883 cylinder heads

      3.515 bore results in 1212cc displacement

   - Custom fitting of your pistons to the cylinders

   - Rings, pins, locks, and circlips

   - Cometic EST top end gasket set

Ordering Information 

To make this kit even better, see options below.

Street Dominator 883 to 1250 Conversion Package - From $700.00

The famous NRHS 1250 kit is now available in a conversion package! This kit takes your 883 to the largest displacement that will fit into the stock cases without the hassle and expense of case boring. These kits are available in your choice of cylinder construction: full cast iron, Nik-a-Sil Plated alumiunum or the traditional iron lined aluminum. The Axtell cast iron cylinders are extremely stiff and will not distort giving the best ring seal of any cylinder we carry. The Nik-a-Sil plated all-aluminum Axtell cylinders last longer and are structurally much more stable than the original equipment piece, providing better ring seal over the life of your engine. Plus they run cooler and reduce friction, making piston scuffing problems a thing of the past. The iron lined aluminum construction offers excellent heat dissipation together with the structural integrity and ring seal of a thick ductile iron liner that wears much less than the factory cylinder. Coupled with premium NRHS Hurricane Forged pistons, Total Seal rings, and Cometic gaskets, we feel this is the ultimate kit for your Sportster! Cast iron cylinders come only in black baked finish. Powder coatings is available for an additional $100.

This kit includes:

   - One set of premium Hurricane reverse-dome conversion pistons in 3-9/16 bore

      these provide a 10:1 compression ratio with your stock 883 cylinder heads

   - One set of new Axtell Nik-a-sil plated aluminum cylinders, Axtell cast-iron cylinders, or NRHS iron lined aluminum cylinders

   - Rings, pins, locks, and circlips

   - Cometic EST head/base gasket set

Actual results obtained in the NRHS shop from our 2004 Sportster XL 883:

This provides an idea of what to expect from the NRHS/Axtell Street Dominator conversion kit when used with your 883 heads and supporting components*. Only the head preparation level was changed between the top three pulls, all other components remained the same. The original stock 883 result is also shown for reference, in purple. That's right, with the bolt-on 1250 kit and these supporting parts, you can more than DOUBLE the power of your stock 883. You won't believe how much more fun your bike will be!

For even more power, swap your 883 heads out for a set of NRHS prepared Thunderstorm or XB Heads. Many NRHS customers have made over 100 rear wheel horsepower using these higher flowing heads with the 1250 kit. The bikes are smooth, strong, reliability is unaffected, and longevity is actually improved.

* - The bike that generated this dyno sheet is also equipped with a HurricaneFlow Air Cleaner, Mikuni HSR42 carburetor, SE .536 cams, Supertrapp exhaust system, and Daytona Twin-Tec ignition.

Ordering Information

NRHS Iron Lined Aluminum Cylinder Kits

Axtell Cast Iron Cylinder Kits

Axtell Aluminum Cylinder Kits

Options to Make These Kits Even Better!

Want even more performance out of your conversion? Consider more optimized piston/chamber configurations as well as improved valvetrain components. Again, NRHS offers premium parts and services to help make your conversion a success!

Ordering Information 

PERFORMANCE TIP: Angle cutting the squish band helps flow into and out of the cylinder by creating less of a shelf for the intake charge and exhaust gases to go around. It also helps combustion efficiency by aiming the fuel coming out of the squish band more directly at the flame front.