New Here, building drag bike with Buell M2

[EarlyRider]

I am new here and haven't worked on a Sportster motor since the 1960s. I am building a Drag Bike using a 1997 Buell M2 (Sportster). Can someone identify the main differences in the Buell motor. I have the heads and barrels off and see Buell cast on the head and some obvious smoothing around the valve guides but not sure if it was done after the fact. it also has Andrews N6 cams. any tips are much appreciated.

[Maxeffort]

Originally Posted by EarlyRider

I am new here and haven't worked on a Sportster motor since the 1960s. I am building a Drag Bike using a 1997 Buell M2 (Sportster). Can someone identify the main differences in the Buell motor. I have the heads and barrels off and see Buell cast on the head and some obvious smoothing around the valve guides but not sure if it was done after the fact. it also has Andrews N6 cams. any tips are much appreciated.

I believe those bikes were stock with N6 spec cams. The heads should be lightning heads which have a 62cc chamber and aren't considered good performance heads. I haven't heard about any factory porting on them.

For more head information and photos go to Hammer Performance.
https://www.hammerperf.com/ttxlheads.shtml

You don't say what kind of drag racing?

[aswracing]

The 1997 M2 had Lightning heads, which are really just a smaller chamber version of the standard XL1200 hemi head. The smaller chambers bump up the CR to about 10:1.

The flywheel assembly is also a Buell-specific piece and is slightly lighter than the Sportster version.

Other than those two things, it's identical to the 1997 Sportster motor. Same cams. Same pistons. Same everything.

The 1997 M2 motor was factory rated for 83hp, which is 70ish as measured at the rear wheel on a Dynojet. In addition to the increased compression and lighter flywheels, the Buell air cleaner and exhaust are part of the reason for that number being a big stronger than a stock Sportster of the day.