What is the purpose of this passage in the head?

[TheBocSez]

Right in the center of the intake side of the cylinder head is a small rectange passage. I am installing my intake and Felpro 1250 gasket and want to know what the purpose of the passage is? Should I used the gasket insert with the opening or the gasket insert that blocks it off?

I will be removing the smog pump with the installation of the new engine and have the passages in the back of the head for the smog tube blocked off.

Thanks!

 

[jrichker]

The passage is for the EGR system. Please keep in mind that the EGR system is separate from the smog pump or Thermactor Air System that pumps air to the heads & cat converters.

Disabling the EGR without a coresponding change in the computer can result in a part throttle ping that is very annoying and possibly damageing to the engine. The EGR system shuts off at WOT, so it has no effect on full throttle performance.

 

[TheBocSez]

I plan on leaving the EGR alone. So I should install the inserts that leave the hole open then?

 

[jrichker]

I plan on leaving the EGR alone. So I should install the inserts that leave the hole open then?

Leave the inserts out to enable the EGR system.

Blocking them disables the EGR by blocking the supply of exhaust gas to the EGR valve.

 

[TheBocSez]

Will do, Thank you.