Last weekend I had the great fortune to go for a drive with my 41 Chevy. Later that day, I decided to take my 42 out as well. I noticed that the idle speed on both trucks slow slightly when they are fully warmed up. Both are 235's, the 41 has a Carter, the 42 a Rochester carburetor. Both carburetors have been rebuilt, both have manual chokes, and the choke/throttle cables work as originally designed.
So why does the idle speed change? I suspect it is a combustion chamber temperature relationship. Any wisdom to share?
