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EGR Valve?

Discussion in 'The Garage' started by mikelucky, Apr 8, 2005.

  1. mikelucky

    mikelucky Registered Member

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    I have a 74 blazer that needs valve cover and intake manifold gaskets. I decided to just tear it down and replace the manifold, carb, fuel pump, and related gaskets in the process.

    Anyone know how to tell if an EGR valve is installed without taking the carb off?
    I'm shopping for manifolds and carbs!

    thanks
     
  2. pauly383

    pauly383 Daddy383 Staff Member Moderator

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    Passenger side , between rear portion carb and valve cover is where your EGR rests . You would actually bang your valve cover into it taking the cover off if you aren't carefull :k5: :k5:
     
  3. PhoenixZorn

    PhoenixZorn 1/2 ton status

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    I have a Holley Street Dominator manifold I want to get rid of... pm me for details... rated for 5500 rpm
     
  4. mikelucky

    mikelucky Registered Member

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    another question...

    OK, so the hose from the EGR is cut off and plugged with a screw, meaning that it is sending no exhaust gas into the manifold.
    I have done a lot of reading, and all I can tell is the reduction of engine ping and reduction of NOx gas.
    Any repercussions (other then these), say mechanically speaking, from installing a non-EGR manifold in place of the EGR one and removing the rest of the EGR equipment?
     
  5. pauly383

    pauly383 Daddy383 Staff Member Moderator

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    Keeping the EGR aint gonna hurt anything . It won't even be that ugly if you have nice valve covers and an air cleaner . You can do away with the ported vacuum switches if you want :k5: :k5:
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    Only problem you will actually notice with removing EGR from my experience, is that you will run lean under certain conditions (cruise) which results in a surge.

    You would have noticed that by now though, since it's already inoperative.
     
  7. mikelucky

    mikelucky Registered Member

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    I guess I should have been more specific...sorry :confused:
    I came across a NON-EGR Edelbrock Performer manifold for a good price. Will there be any downside to swapping the manifold?
     
  8. ssls6

    ssls6 Registered Member

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    First off, a 74 did not come with EGR (exhaust gas recirculation). It did come with a PCV valve (positive crankcase ventilation) and maybe AIR injection depending on where it was bought and/or transmission combination.

    Newer cars and trucks have EGR valves. This valve goes into the intake manifold (on most vehicles) and plumbs to the exhaust manifold. Real exhaust (not just blow-by) is redirected to the fresh air stream.
     
  9. mikelucky

    mikelucky Registered Member

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    OK, I know I'm new at this, but doesn't the PCV valve install directly into the valve cover?

    As stated below, pass. side, below carb, is a gold disc shaped valve connected to the intake manifold. It has a black rubber tube connected to it that (from what Ive read) attaches somewhere nearby to an exhaust port. This tube is only 6 inches long and now has a screw in the end of it.
    I'm pretty sure its an egr, and most of what I read states that egr started in the early 70's. Maybe I should post a pic to be sure.

    EGR equipped manifolds essentially have a hole in them so that the egr valve can push exhaust gas into the mix. So, if I choose to use the non-EGR manifold, then there should be no mechanical need for the EGR or vacuum switch.

    Right?
     
  10. ssls6

    ssls6 Registered Member

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    I would NOT buy a EGR equiped intake manifold. If you did, then plug off the intake opening.

    Here is what you should have. In the passenger valve cover you should have a breather (looks like a mushroom that pushes into the cover). On the drivers side valve cover you should have a PCV valve. The PCV valve connects to either the intake manifold or carburetor using 3/8th vacuum line. The normal case is connected to the carb. Your vacuum brake booster can also connect to the carb but is usually connected straight to the intake. Your vacuum advance should be connected to the ported vacuum port on the carb. It is located nearest the choke on the side. Other vacuum accessories like the tranny or heater controls connect to unported vacuum (either the carb or intake).
     

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