I am building a 57 station wagon and I was cleaning my intake getting ready to paint. Its a 4bbl intake from a 347. Inside the exhaust crossover is a small copper? pipe. What does it do? It does not appear to go anywhere. Its not for the choke. If any one knows what this is let me know. Mine is broken and I am trying to figure where to go from here. Thanks
Try the experts with a photo or two at www.hamiltonintakes.com Brad and his crew are not full time but some of the best for this question I know. Good luck. Normbc9
Are the carb and intake a "matched set"? Does the carb have an integral choke, with the thermostat attached to the carb body? If so, where else might the thermostat pick up heat to operate the choke? Can't think of any other reason for there being a heat tube in the exhaust crossover passage.
On my 60 389 there is a tube that goes thru the exh crossover but its a press-fit at both ends. There is a hole in the intake manifold on top of the crossover that a choke tube goes into. The air in the crossover heats up the air that is sucked thru this pressed tube and that air is what heats the choke bimetal. My explanation is probably clear as mud....don't know if the 57 setup is the same. Go onto the Performance years (PY) tech forums and you can most likely get your answer....it's all Pontiac!
there is 90% rochester and 10% carter 1957 according to experts and they used the same intake so ponco 60 is right there is one line inside crossover and one from intake to carburator bi-metal choke using the same fitting.
This tube is used to supply heated air to the choke housing. I have had mine rebuilt because it also was broken. A new tube was just slipped into place after drilling out the old one at its ends.