Egr

[aerie1761]

Im replacing my intake manifold do I want to stay with the egr setup or do I go non egr what is best thanks

 

[Enigma]

If I'm correct. The EGR is there to allow the hot gases from the exhaust to pass thru a chamber in the intake manifold to heat it up during cold days. This allows for better combustion. I have mine still installed but the vaccuum hose is blocked off since I do not drive the car in cold weather. If you never plan to drive it in the winter or really cold days, I would go with the non-egr intake.

Maybe some others here have a different opinon.

Good luck

Enigma

 

[81 Corvette]

From the1981 GM Shop Manual:

The Exhaust Gas Recirculation System is used on all engines. It meters exhasust gas into the induction system for recirculation through the combustion cycle to reduce oxides of nitrogen emissions.

The EGR valve remains closed during periods of engine idle and decelration to prevent rough idle from excessive exhaust gas dilution in the edle air/fuel mixtures.

 

[81 Corvette]

The air heating you are talking about is on teh drivers side. There is a "stove pipe" that goes from the exaust manifold to the snorkle on the air cleaner. When cold, a door opens in the snorkle to allow heater air into the carb. When the engine warms up, the door closes and allows cool air from the air damn on top of the radiator.

 

[Bob Chadwick]

I just replace my manifold with a non-EGR Performer. I posted about it and there was no reason not to remove it.

 

[JohnZ]

No need to use an EGR manifold unless your state has emission testing and inspection that requires it.

 

[8T8T2]

I replaced my intake with the performer non-egr this last winter. She passed emmisions with the old one blocked off so I figured why pay the extra money for the intake with one if I wasn't going to use it anyway.

 

[MaineShark]

There are several items being described here.

The "heat stove" takes hot air from the external surface of the exhaust manifold and uses it to pre-heat the incoming air on cold days. No direct interation between exhaust gas and intake.

The "heat riser" blocks off the righthand exhaust manifold, forcing the exhaust gas to cross through a passage under the plenum in the manifold, in order to get to the lefthand manifold and out of the car. Again, the exhaust gas stays separate from the intake charge.

The EGR system actually introduces a small amount of exhaust gas into the actual intake side of the manifold. By virtue of containing very little oxygen and fuel, this gas essentially reduces the efficiency of the engine, keeping combustion temperatures cooler, which reduces production of nitrogen oxides. It also does help the prevent detonation/knock in some engines, but the consensus seems to be that our engines don't need it to help in that department.

Joe