BIG BORE KITS

Quick Links:

• Bolt-on 1250 Kits for 1986-present Sportster and 2004-2010 Buell XB12

• 883 to 1212 Conversion Kits for 1986-2008 Sportsters

• Bolt-on 1050 Kits for 2003-2010 Buell XB9

• 88 & 90 Cubic Inch Kits for 1986-present Sportster and 2004-2010 Buell XB12

• 1200 Kits for 2003-present Buell XB9

• Custom Kits

BOLT-ON 1250 Kits from HAMMER PERFORMANCE

For 1986-present Sportsters and 2004-2010 Buell XB12

SPECIAL INTRODUCTORY PRICE OF ONLY $699.95

Our 1250 Kits let you take your Sportster or Buell XB12 out to 1250cc with no case boring required. It's a bolt-on kit that can be installed in an afternoon without removing your engine from the frame!

Each kit comes standard with the best components on the market:

• Sledge Hammer 3-9/16 Bore Iron Lined Aluminum Cylinders
• Sledge Hammer 3-9/16 Bore Forged Pistons
• Lightweight Tool Steel Wrist Pins
• Circlips
• Premium Quality Moly Faced Rings,
• Premium Quality .030 Head and .020 Base Gaskets (upgrade to a full top end set available)

Sledge Hammer cylinders feature an extra heavy duty iron liner and aluminum fin construction. This design gives the best of both worlds: a strong, stable bore for maximum ring seal and the heat dissipation you need for extreme conditions. The iron liner material is also rock hard for a long, trouble free life.

Complementing these great cylinders is a set of our exclusive forged Sledge Hammer pistons. These pistons are lighter than the competition's for more power and less vibration, without sacrificing any strength. They feature extra large valve pockets for those radical cams, anti-detonation grooves, dual wrist pin oilers, expansion grooves for superior ring seal, and ribbing to give maximum strength with minimum weight. You cannot find a finer piston for your HD or Buell

Unlike some of the other kits out there, we custom hone every set of cylinders to the exact set of pistons that are included in the kit. This gives a much more precise fit than you can get when slapping together off-the-shelf cylinders and pistons, resulting in better ring seal and longer life. Close is not good enough, we want it perfect!

For the ultimate in convenience, add our pre-assembly option. We'll thoroughly clean your cylinders, precisely gap your rings, and then pre-lube and assemble the pistons and rings into the cylinders. The ready-to-install assembly will then be shipped to you in a sealed plastic bag to keep it clean and safe. This service makes the installation a breeze, as you simply lower the piston down enough in the bore to expose the wrist pin hole, position it over the connecting rod, insert the wrist pin and circlip, and push the cylinder down into position. No special tools required!

Note: Our 1250 Kit cylinders have the 86-03 small style fins. They still fit and work fine on 2004-up bikes although the head fins will be a little bit larger than the cylinder fins. Most people can't tell the difference.

GET THE BEST! GET A 1250 KIT FROM HAMMER PERFORMANCE TODAY!

Note 1: the 30 degree x .400 dome race pistons are designed to be cut down to achieve your desired compression ratio, call for details
Note 2: 1250 kits are also available with AXTELL full cast iron cylinders on a special order basis. Axtell cast iron cylinders offer the ultimate in bore stability and ring seal but have a weight penalty of approximately 6lbs per cylinder. They are highly recommended for maximum effort engines.

1250 Kit Options
Description	Price	Add to Cart
Gap Rings and Pre-Assemble Engine Kit	$40
Upgrade Head & Base Gasket to Full Top End Gasket Set	$40	Select Top End Gasket Set 1986-1990 .030 Head/.020 Base - C9907 $40.00 1986-1990 .040 Head/.020 Base - C9762 $40.00 1991-2003 .030 Head/.020 Base - C9854F $40.00 1991-2003 .040 Head/.020 Base - C9763 $40.00 2004-2006 .030 Head/.020 Base - C9971 $40.00 2004-2006 .040 Head/.020 Base - C9970 $40.00 2007-Up .040 Head/.020 Base - C9177 $40.00 04-10 Buell XB12 .040 Head/.020 Base - C9856 $40.00

Tip: Choose your top end gasket set based on the type of rocker boxes you're using. The head and base gaskets all interchange from 1986-present.

Hammer Performance Bolt-On 1250 Kit in Black
15 Degree Domed Pistons for Thunderstorm Heads

883 to 1212 Conversion Kits for Sportsters - Only $485!

For 1986-2008 Models

Want big power without spending big money? The HAMMER PERFORMANCE 883-1212 conversion kit is for you!

Send us your 883 cylinders and we'll bore them to a full 3.515" bore using our exclusive CNC boring process. We'll then hone them to a perfect fit with a set of premium quality light weight Sledge Hammer forged pistons. Rings, wrist pins, and premium quality rubber coated steel .030 head and .020 base gaskets are all included. Optionally, you can upgrade to a complete Cometic EST top end gasket set.

For the ultimate in convenience, add our pre-assembly option. We'll thoroughly clean your cylinders, precisely gap your rings, and then pre-lube and assemble the pistons and rings into the cylinders. The ready-to-install assembly will then be shipped to you in a sealed plastic bag to keep it clean and safe. This service makes the installation a breeze, as you simply lower the piston down enough in the bore to expose the wrist pin hole, position it over the connecting rod, insert the wrist pin and circlip, and push the cylinder down into position. No special ring compressor tool required!

Note: Starting in 2009, HD changed the cylinder construction and 883 cylinders can no longer be bored to 1200. If you need cylinder cores for your 2009 or later model, call us, we may have some.

Hammer Performance 883-1212 Conversion Kits for Sportsters These kits require that you send us a serviceable pair of cylinders for boring and honing. Cores may be available, call for availability and price
Heads	Dome Type	Compression Ratio	Price	Add to Cart
86-Present XL883	Reverse	10:1 @49cc	$485
88-03 XL1200 95-96 Buell S2	Radius	10.5:1 @67cc	$485
98-03 XL1200S 96-03 SE/Lightning 96-98 Buell S1 97 Buell S3 97-98 Buell M2 (Lightning Heads)	10 Degree	10.5:1 @62cc	$485
98 Buell S1W & S3 99-02 Buell all	15 Degree	10.5:1 @67cc	$485
86-87 XL1100 04-present XL1200 04-present SE 04-10 Buell XB12	Rectangular	10.5:1 @62cc	$485
Custom Application	Flat Top	9:1 @67cc	$485
Race Application	30 degree x .400	Machine for Desired CR Note 1	$485

Note 1: the 30 degree x .400 dome race pistons are designed to be cut down to achieve your desired compression ratio, call for details

883-1212 Kit Options
Description	Price	Add to Cart
Gap Rings and Pre-Assemble Engine Kit	$40
Upgrade Head & Base Gasket to Full Top End Gasket Set	$40	Select Top End Gasket Set 1986-1990 .030 Head/.020 Base - C9907 $40.00 1986-1990 .040 Head/.020 Base - C9762 $40.00 1991-2003 .030 Head/.020 Base - C9854F $40.00 1991-2003 .040 Head/.020 Base - C9763 $40.00 2004-2006 .030 Head/.020 Base - C9971 $40.00 2004-2006 .040 Head/.020 Base - C9970 $40.00 2007-Up .040 Head/.020 Base - C9177 $40.00 04-10 Buell XB12 .040 Head/.020 Base - C9856 $40.00

Tip: Choose your top end gasket set based on the type of rocker boxes you're using. The head and base gaskets all interchange from 1986-present.

1200 Kits From HAMMER PERFORMANCE!

For Buell XB9 - From $1200

HAMMER PERFORMANCE now has a 1200cc kit for your Buell XB9! Call us today or check back here for details.

Custom Big Bore Kits From HAMMER PERFORMANCE!

Need a special bore size not listed here? Need a custom spigot size, cylinder height, or piston compression height? HAMMER PERFORMANCE can fix you right up! We've done lots of different engine kits over the years for specific displacement classes, different fuels, and different conditions. We have the experience and knowledge to make your project a success, and we can work with the various vendors of cylinders, pistons, and rods to put together the combination that works for you. Call us today!