I got the pic from the "pulled my engine" thread a few threads down.



What are they?
What do they do?
How do they work?

 

^^

 

^^ bottom ones

 

Those two little holes under each exhaust port do the same job as the exhaust port?

 

If you use the stock exhast gasket, there is a hole in it for one of those holes under the exhaust port but I am not sure if that matches up with anything on a stock exhast manifold.

Certainly, both those holes get covered up if you use an "aftermarket" gasket and manifold.

I don't know what they are for.

 

That engine looks familiar....

 

That engine looks really good, too.

 

Depending on what model year/car/gaskets you are using those will allow air to be injected into the exhaust port by the ACV. The middle hole also functions with the EGR system I believe. They're all worthless from a performance standpoint

Brian