Skippy,
My original post was objecting to your post cutting down Yenn's suggestion of a Lyc 0-320 for a 4 seat 120 kt cruise aircraft to build. Not to see who has the biggest one.
But It seems you just want to compare RAA/LSA aircraft and power plants. Lycoming don't have much to offer here but I'll bring you up to date.
Lycomings only LSA engine, the 0-233/i0-233. I can't remember the actual weights but the Lyc is a bit heavier than the Rotax.
116 hp, roller rockers, electronic ignition, TBI (Eagle throttle body injection) on the i0-233 and tuned 1.5" cross-over exhaust system. Runs on ULP and like all lyc's has manual mixture controll so can go LOP at cruising altertude. Oh, and has a slow reving prop as it is a slow reving engine with a TBO at 2500 hrs.