EGR heads, non-EGR intake manifold. Bad thing?
06-06-2002, 07:56 PM
#1
Burning Brakes
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EGR heads, non-EGR intake manifold. Bad thing?
The intake manifold is an Edelbrock Performer 2101 and I've only run it for about 2 months and even then infrequently. Trouble is I still have the 333882 heads on it but the 2101 is not an EGR manifold. When I took it off I found a layer of carbon through the heat riser passageway about 1/4" thick. Is this going to lead to troubles down the road?
06-06-2002, 09:35 PM
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Burning Brakes
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Re: EGR heads, non-EGR intake manifold. Bad thing? (Cookwithvette)
No! Most of us plug the passage ways, it keeps the oil from frying when it hits the bottom of the intake manifold. That carbon crud you saw will block the intake in a few years anyway. So dont worry abought
06-07-2002, 08:27 AM
#4
Team Owner
Re: EGR heads, non-EGR intake manifold. Bad thing? (Cookwithvette)
Actually the exhaust crossover has little to do with EGR in it's original intent, it's for heating the carb and choke pull off, so in Minnesota winters the car is still driveable, the further south you live, and in Maryland where I used to live, I blocked many a crossover pasage in the manifold with plaster of paris, fill the crossover passage completely, smooth the ends, let it harden and don't worry about moisture.....car runs much cooler in summer time, which is all the time in Florida/SW, etc...saves a lot of gasket/overheating related problems....
EGR only added to the coaking problems with the added passageways and the valve itself, thing is eliminating it without recalibrating the carb a bit on the off-idle transferr circuit will lend to bogging, too lean a very light throttle....it was a mystery to me what caused that, but Brad Urban some years ago explained it to me...it's a smog/EPA thing, and if we trace the small square slots in the primary barrels, near the throttle blades, up through the carb passageways, we find 2 out of the 4 brass tubes, those 2 need to be drilled ever so slightly, with a numbered bit, about 2 sizes bigger, a very small amount....that richens up that light throttle transferr circuit enough to kill the bog......also having a tite throttle shaft in the base plate, no egg shaped bearings helps immensley too....
GENE
EGR only added to the coaking problems with the added passageways and the valve itself, thing is eliminating it without recalibrating the carb a bit on the off-idle transferr circuit will lend to bogging, too lean a very light throttle....it was a mystery to me what caused that, but Brad Urban some years ago explained it to me...it's a smog/EPA thing, and if we trace the small square slots in the primary barrels, near the throttle blades, up through the carb passageways, we find 2 out of the 4 brass tubes, those 2 need to be drilled ever so slightly, with a numbered bit, about 2 sizes bigger, a very small amount....that richens up that light throttle transferr circuit enough to kill the bog......also having a tite throttle shaft in the base plate, no egg shaped bearings helps immensley too....
GENE
06-07-2002, 08:37 AM
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Re: EGR heads, non-EGR intake manifold. Bad thing? (mrvette)
Basically agree w/ above. SOP for me in the South to block heat riser.
The stock Q-J has a lean idle mixture so the idle mixture can be made richer to handle the transition from idle.
Holley & other carb users should not have a problem.
:cool:
The stock Q-J has a lean idle mixture so the idle mixture can be made richer to handle the transition from idle.
Holley & other carb users should not have a problem.
:cool:
06-07-2002, 08:40 AM
#6
Re: EGR heads, non-EGR intake manifold. Bad thing? (mrvette)
Nice one Gene :)
That description of the off idle hesitation perfectly describes what I'm getting (no EGR/EFE, 2101 manifold). Would the two tubes that need opening out be the inner 2 of the 4 that hang down from the air horn?
:cheers:
That description of the off idle hesitation perfectly describes what I'm getting (no EGR/EFE, 2101 manifold). Would the two tubes that need opening out be the inner 2 of the 4 that hang down from the air horn?
:cheers:
06-07-2002, 10:39 AM
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Burning Brakes
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Re: EGR heads, non-EGR intake manifold. Bad thing? (mrvette)
Hmm... This could explain why the previous owner had the Quadrajet set slobbering rich and still had a strange power problem at part throttle.
Ganey, you're right, no bog with the Demon. SHARP off idle response.
This is all very informative. I never really knew what that extra passageway was for but. I had assumed exhaust but where the heck would it go? Does it just shoot exhaust gasses back and forth between the two heads? Strange.
You can see in my sig that my next engine will be fuel injected, now I know what type of heads to get. Thanks guys!
:cheers:
Ganey, you're right, no bog with the Demon. SHARP off idle response.
This is all very informative. I never really knew what that extra passageway was for but. I had assumed exhaust but where the heck would it go? Does it just shoot exhaust gasses back and forth between the two heads? Strange.
You can see in my sig that my next engine will be fuel injected, now I know what type of heads to get. Thanks guys!
:cheers:
