Is it possible on my BBC that the valves are more likely to float when the engine gets warmer. I had a mud drag this weekend and everything worked fine except for the last race. The motor got up to about 230 degrees and I took off it was good then it started popping out the exhaust. I have had this problem before and I changed carburators and it seemed to do the trick. Now this one race confuses me. Cost me the race too. I have no idea how many miles are on this motor but it does have a new cam and lifters in it. So i was thinking the valve springs are getting weaker as they get warmer.