Okay, does anybody have a cross section showing what EGR heads look like and how they look different from non EGR heads. I'm curious because I still don't know what I'm looking for to tell if the heads have EGR.

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, Jon (91 RS too many mods to list)

 

a head that has the egr passage will be in the middle of the head... it is a passage for exhaust gas to go through to recirculate it into the manifold (Exhaust Gas Recirculation... EGR) both heads have this and they are connected by a passage that runs through the middle of the manifold base... the aluminum vette heads do not have this provision.... they have a tube that runs from an exhaust manifold (pass side) to a port on the intake...

 

as far as what they look like... heads with the EGR passage have five ports (passages) on the intake side... the ones without have four... on the exhaust manifold side they both have four... (this is per head of course...)

 

No EGR port:


If there was one, it would be right in the middle of the intake face of the head

 

The multiport 2.8/3.1 v6's also use a tube to connect the exhaust manifold with the throttle body.

However the 2.8/3.1 heads have the remnants of the EGR passageway! The hole is still in the head, and the head-to-intake-manifold gasket has a matching hole. However, the intake manifold hole is just a little indent, maybe 1/2 cm deep- and it ends. No more EGR passageway.

(The 2.8/3.1 EGR passageway was present on the 82-84 carb'd motors.)


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

I always just thought that was for coolant to pass through and into the intake manifold to warm that up. How do the heads look inside? So the intake manifolds have a tube that comes out of them on the passenger side and goes into the intake somehow. Is it possible to get an intake gasket that will block off that passage?
Thanks, now if only I had a cross section of the head to see what the EGR looks like.

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, Jon (91 RS too many mods to list)

 

I dont think there would be any way to block it off with a gasket, because it would probably get burnt up and sucked into the intake. But maybe if you got EGR heads and an intake that was non egr it would work, because thn there would be metal covering the holes in the heads.

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1983 Pontiac Firebird SE
LG4-Based Chevy 400
700R4 Tansmission
Modified 4 Barrel Q-Jet Carb
Accel Super Stock 8mm Wires
Edelbrock Pro-Flo Air Cleaner
3.23 Posi Rear
14X7" Cragar SS/T Wheels
35X4 CD/AM/FM Head Unit
100WX2 Amp
2 Pioneer 12" Subs in Custom Box
Third Gen Performance

 

Most people just block off the EGR valve with a piece of aliminum can or if you can fabricate a 1/4 block to replace the spacer.

I have a question, does blocking off the EGR valve hurt/help/no-effect to gas milage and emmissions testing?

It seems that there is always something wrong with it and it causes crappy performance/idleing/misc. things. It seems like blocking it off would cure more things then not... right? I still need it for the visual check, but if it was still blocked off, would it still pass? The computer is disconnected too...

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock... all the suspension stuff... 9-bolt posi disk is in... K&N filter... 93 octane...

-=ICON Motorsports=-