Engine Question

[08herobolt]

I was wondering if someone had an answer about and S1 engine. I'm looking at buying one and building it up. What engine is in the S1? I know it's a early Thunderstorm engine, but I'm looking for cams, valves, etc. Places like Jim's and Andrew's don't have the "Thunderstorm" name. Is it an XL, Twin Cam, etc.

Thanks in advance for the answers. I really appreciate it.

JP

[pur pony]

XL... XL is the Sportster engine which is the same as the Buell.

[konarider94]

this is a good comparison on the different heads used throughout the years.
http://hammerperf.com/ttxlheads.shtml

Same as the XL with the exception of compression ratio and cams. I think the s1 has .497 cams stock.