ANTIQUE BIPLANE AND AN SMA TWIN HAVE NMAC IN TFC PATTERN.

Narrative

TWR CLRED ME FOR LOW APCH TO RWY 35L. WIND WAS RPTED AT 230 DEGS AT 10 KTS. AFTER APPROX 1000 FT DOWN RWY 35L; I PULLED UP AND APPLIED CLB PWR. AFTER APPROX 30 SECONDS; I NOTICED 2-300 RPM FLUCTUATIONS IN TACH INDICATIONS. I CONTINUED THE CLB TRYING TO DETERMINE ENG SIT AND MAINTAINING RWY HDG 350 DEGS. WIND NOW 250 DEGS AT 10 KTS (PER TWR). APPROX 2 MINS LATER; TWR ASKED ME TO VERIFY LOW APCH TO RWY 35L. I VERIFIED AND STATED I WAS NOW L XWIND TURN. A FEW SECONDS LATER; TWR ADVISED ME THAT IT APPEARS YOU HAVE DRIFTED OFF AND INTO DEP PATH OF RWY 35R; USE CAUTION. 30 SECONDS LATER; I ADVISED TWR THAT I WAS GOING TO HAVE TO LAND AND REQUESTED RWY 28. ENG INDICATIONS WERE STILL ERRATIC AND CONTINUED WITH A NORMAL LNDG ON RWY 28. SMA Y WAS DOING TOUCH AND GOES ON RWY 35R WHILE I WAS UPWIND ON RWY 35L AND RPTED A NEAR MISS TO TWR. ON GND AT MY HANGAR; I CALLED TWR ON LAND LINE AND RELAYED PERTINENT INFO. SEVERAL FACTORS PLAY INTO THIS: 1) NOT ENOUGH XWIND CORRECTION FOR VARIABLE WIND CONDITIONS. 2) FAILURE OF OVERTAKING ACFT TO GIVE (YIELD) RIGHT OF WAY. 3) NO TWR COM ADVISING OF POSSIBLE CONFLICT UNTIL AFTER THE FACT!