blocker plates on exhaust crossover

[kendallpeterson1963]

i recently pulled off my intake manifold, and there were metal plates covering the crossover holes...what is the point of them? should i keep them on or not? having them blocked off is not allowing the choke stove to heat up all of the way causing my choke to never completely come off.

 

[melsg5]

A cooler intake charge produces more horsepower, thus someone blocked them to prevent the intake from getting too hot. Depending on where you live and how cold it gets can you compensate with the choke adjustment to cause it to be fully open when the engine is fully warmed up.

 

[HighSchool66]

Is the heat riser needed?

I too am interested in the need for the crossover feature. I'm debating whether to block it off to prevent paint discoloration of the intake manifold, but I don't know how well the original carb will operate. Its' a 1966 2-barrel 326.

Can anybody out there report good driveablity after fully or partially disabling the heat riser circuit? In my case, I'll only be driving on nice Summer days.

 

[melsg5]

In warm weather it will not have a negative effect on engine performance.

______________________________

 

[old man]

heat passages

If you end up with a hesitation on take off this will be your problem.

 

[Too Fast]

I would routinely block off my crossover passages. Like Mels says, cooler = denser, and for the weekend nice day cruiser, it will drive fine. Choke settings are adjustable.