I was looking at the Vortec heads, and I found a GMPP Vortec Intake w/ EGR. My question is why would GM make an intake manifold w/ EGR for the Vortec pattern if none of the Vortec heads have the EGR passages? Am I correct in assuming that these EGR passages in the head are needed to supply the intake manfiold with the exhaust gas?

Basically, can somebody explain to me how and where the flow comes from and goes for the EGR system? For example is the exhaust picked up from the exhaust runners and channeled through EGR passeges in the head to the intake's EGR port and then to the valve???

Any help on the function of this system is greatly appreciated,

Jason

 

In its simplest form...

EGR picks up ex. gasses in the ex. stream usually in the cylinder heads (some cars get it from the ex. manifold) and passes it to the EGR valve.

The valve opens when conditions are met (throttle position, engine load, ECM signal, etc.) and ex/ gasses are then let into the intake passage. This helps cool the firing in the cylinder.



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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R

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