Blocking off EGR Valve
Thread Starter
Instructor
Joined: Jun 2004
Posts: 162
Likes: 1
From: Johnsburg IL
Blocking off EGR Valve
Has anyone had problems with using a block-off plate for the EGR Valve? I heard or read once doing so can create carbon build up in the manifold.
Any knowledge shared is appreciated.
Any knowledge shared is appreciated.
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
It can indeed create carbon buildup in the exhaust crossover. My car had the blocking plate in place when I bought it. When I did the head swap, there was carbon in the passages below the plate.
However, I don't consider it to be a serious issue...
However, I don't consider it to be a serious issue...
Race Director
Joined: Sep 2002
Posts: 10,362
Likes: 5
From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by colorado1967
Has anyone had problems with using a block-off plate for the EGR Valve? I heard or read once doing so can create carbon build up in the manifold.
Any knowledge shared is appreciated.
Any knowledge shared is appreciated.
the only anomoly is carbon and that is easily cleaned. Valves last at least a 100K miles, and you know when they go bad (sticking open) by the bad idle. Of course, the system that sends vacuum to open the EGR could go bad too, causing it to get vacuum at idle - but that's a rare event.
Why do you want to get rid of the valve anyway?
Burning Brakes
Joined: Nov 2004
Posts: 1,193
Likes: 176
From: Hillsborough NC
Originally Posted by SanDiegoPaul
Exhaust Gas Recirculation has no ill effects though. It is a harmless smog device that can reduce cylinder temps, and thereby actually reduce ping.
the only anomoly is carbon and that is easily cleaned. Valves last at least a 100K miles, and you know when they go bad (sticking open) by the bad idle. Of course, the system that sends vacuum to open the EGR could go bad too, causing it to get vacuum at idle - but that's a rare event.
Why do you want to get rid of the valve anyway?
the only anomoly is carbon and that is easily cleaned. Valves last at least a 100K miles, and you know when they go bad (sticking open) by the bad idle. Of course, the system that sends vacuum to open the EGR could go bad too, causing it to get vacuum at idle - but that's a rare event.
Why do you want to get rid of the valve anyway?
Would the bad idle be only at startup, or all of the time? My 78 has a terrible time idling when it first starts and I'm just wondering....
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
Originally Posted by SLVRSHRK
Would the bad idle be only at startup, or all of the time? My 78 has a terrible time idling when it first starts and I'm just wondering....
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Drifting
Joined: Dec 2004
Posts: 1,345
Likes: 3
Originally Posted by SanDiegoPaul
Exhaust Gas Recirculation has no ill effects though. It is a harmless smog device that can reduce cylinder temps, and thereby actually reduce ping.
the only anomoly is carbon and that is easily cleaned. Valves last at least a 100K miles, and you know when they go bad (sticking open) by the bad idle. Of course, the system that sends vacuum to open the EGR could go bad too, causing it to get vacuum at idle - but that's a rare event.
Why do you want to get rid of the valve anyway?
the only anomoly is carbon and that is easily cleaned. Valves last at least a 100K miles, and you know when they go bad (sticking open) by the bad idle. Of course, the system that sends vacuum to open the EGR could go bad too, causing it to get vacuum at idle - but that's a rare event.
Why do you want to get rid of the valve anyway?
EGR hurts engine performance. By adding exhuast mixture to the combustion chamber through the intake valves, there is a lower mass of power producing fuel/air mixture that can be burnt in the limited (by displacement) chamber- that produces less power.
Melting Slicks
Joined: Dec 2000
Posts: 2,198
Likes: 2
From: Eastern Connecticut
Originally Posted by StickShiftCorvette
\
EGR hurts engine performance. By adding exhuast mixture to the combustion chamber through the intake valves, there is a lower mass of power producing fuel/air mixture that can be burnt in the limited (by displacement) chamber- that produces less power.
EGR hurts engine performance. By adding exhuast mixture to the combustion chamber through the intake valves, there is a lower mass of power producing fuel/air mixture that can be burnt in the limited (by displacement) chamber- that produces less power.
IN PARTHOWEVER, that is only at part throttle, so it doesn't matter,and actually lets you run more advance. At full throttle the vacuum goes away and the valve closes. EGR is a lot like vacuum advance, it's only there when you can use it, and goes away when it hurts performance.
There is no good reason to disable the EGR.
Joe
