‘56 400 vapor lock

Posted by Tom Chapman On 2022/5/21 23:07:18

Wondering how many have experienced vapor lock problems with the four barrel Rochester carb. It seems that once the engine gets up to temp, the carb temp itself is up around 145 F. The intake manifold under the carb gets up to around 200 F. I understand there is a path in the manifold where exhaust gas is routed under the carb to help with cold starts, and that there is some kind of valve that is supposed to block this path once the engine is warm? Where is this valve? Does it get stuck? Has anyone had to use a phenolic carb spacer to get around this problem? If so, from where did you get it? Thanks in advance for the help.