Heat Cross-over

[67 GTX]

I am curious about whether or not the heat cross-over in the intake manifold is needed?

Is it a necessity to make sure that the fuel vaporizes, or is it really useless once the car warms up?
What are the advantages to removing it?

I have a stock cast iron manifold on my 440.

 

[Meep-Meep]

I'm in CA and back in the 80's when the gas was different I used to run it open and had no issues. Now FF to 2011 I find that leaving the crossover open causes me problems so I either restrict it to about a 3/8" hole or block it off completely. I had an FE Ford in my old truck and with the crossover blocked it ran like crap until it warmed up - even in the mild CA climate. If you can run with it open I'd do it but I'm sure you will have fuel related problems when the carb is hot.

 

[67 GTX]

I'm in CA and back in the 80's when the gas was different I used to run it open and had no issues. Now FF to 2011 I find that leaving the crossover open causes me problems so I either restrict it to about a 3/8" hole or block it off completely. I had an FE Ford in my old truck and with the crossover blocked it ran like crap until it warmed up - even in the mild CA climate. If you can run with it open I'd do it but I'm sure you will have fuel related problems when the carb is hot.

How long will it take the carb. to heat up if I block the cross-over?

 

[Meep-Meep]

I never timed my cars but seems to me no less than 10 mins of running but could be up to 20 mins for the intake to stabilize. If it's really hot out then it might be less. I plan to actually measure the intake plenum temp with a thermocouple and plot the data on a graph.

 

[67 GTX]

I will probably block the cross-over later today. Thanks for your help.

 

[Cranky]

I always block mine. Usually, the choke can be set up to make it run better while warming up but I generally don't run a choke on my junk.

 

[67 GTX]

I found out that mopar performance makes an intake gasket with the heat cross-overs blocked off. Anyone had any experience with this gasket?

 

[forphorty]

I found out that mopar performance makes an intake gasket with the heat cross-overs blocked off. Anyone had any experience with this gasket?

Get the FelPro with blockoff. I bought the MP one years ago and it was just a conventional valley pan with two square plates provided to block off the crossover.