It does get tighter as it warms up - this always seemed strange to me too Wrinx, but I can confirm it. I had a racecar version of this engine, and because it had no belt guards I could put my hands on the belts at anytime. You need 90 degrees of twist on the longest section when the belt is cold. From this state, after running the engine at 7000 rpm for a few laps the belt gets VERY tight..