| Author | Message | ||
     Wile_ecoyote |
Anyone ever had the oppurtunity to put them on? Will they even work? Are there any advantages? Am I nuts? (yes you are) Who said that? | ||
| Rick_a |
Yes. Simple swap. You'll need XB pistons and an NRHS motor mount. Save some time and money and buy '04 up H-D XL1200 heads...they are the same as the XB heads only they are drilled for the intake mounts. I had Lightning heads and gained 21hp and 7ft-lbs torque with those heads, a cam, and higher compression pistons. They are the highest flowing bolt-on heads from Buell/H-D. They have better ports but slightly smaller valves than the Thunderstorms (.010"). | ||
| Jimidan |
If you use the XB9 pistons with the XB12 heads, it will give you 12.3 to 1 compression ratio, and surprisingly, it is very streetable with 93 octane pump gas. These engines are and very reliable too. Pinging with the bathtube heads simply isn't a problem like it was with the Thunderstorm heads if proper timing is achieved. The squish band should be set at .030" which can be adjusted using Cometic gaskets for the base and head. The flat squish band for this configuration is measured from the portion of the head's deck that overhangs the cylinder to the flat surface of the piston dome at top dead center. This squish is easy to measure by mocking up the heads, gaskets and cylinders under the proper torque and measuring the gap at TDC with small pieces of solder temporarily set in grease on on the dome of the piston, and then rotating the piston through stroke. Dismantle the engine and measure the thickness of the solder with a caliper. This will give you the exact combination of thicknesses of the gaskets needed. Cometic has gaskets of nearly all thicknesses to choose from. Thanks to Aaron Wilson and Battle Twin magazine for sharing this measuring technique. Have fun. jimidan | ||
| Alex |
Again, there is no XB 12 head. There is the XB head which is exactly the same for the XB9 and XB12. You will get a high compression engine if You put an XB9 piston to a stock 3 13/16" stroke crank together with an XB head. Regards Alex |
