[Fordy8man]

im building a 1948 ford pickup with a 1984 351w motor. i want to clean up the look of the motor and wanted to know if i could do away with the egr valve or will it affect anything. the egr valve is mounted to a carb spacer. if i can do away with it i will put a new carb spacer on. not sure if its any help but its a 4bbl intake with a 4bbl holley going on it.
thanks tim

[ernkazern]

You should be able too, especially if you richen up your mixture a little. I don't know of any no legal reason for you not too remove it because it's going into a 1948 vehicle. One of the reasons for the EGR valve was to keep emissions lean engines from pinging. By recycling some exhaust back through the combustion chamber the combustion temps are cooled considerably. This reduces the output of NOX, probably the main reason for an EGR valve, in the exhaust and keeps the engine from pinging. A lot of the 70's and 80's cars pinged like crazy if the EGR valve wasn't working. I imagine you'll be modifying your engine enough so overly lean combustion won't be a problem.

[Sir Joab]

My friend has a 1991 Chevy Suburban with a 350. At one point the EGR valve failed; so he stuck a golf tee in it to plug it. The thing has driven fine ever since. I think I remember something about the EGR being used to help keep the engine cooler by recycling the exhaust into the cylinders to displace some of the fuel/air mixture.

[jimfulco]

If the carb used is calibrated for use with EGR, it will likely run lean at part-throttle without a functioning EGR system, causing detonation during light to medium acceleration. Recalibrate it, or run a carb that's calibrated for non-EGR use, and you should be fine.

[matt167]

yup, anything over 2500* will produce NOX, EGR's open as vac goes down, drops the temps. new EGR's are calibrated to open when the temps require it, with the computer of course

[curtis73]

EGR recycles exhaust gasses back into the intake to lower NOx and (slightly) HC emissions. Removing it will increase those emissions and you'll probably need to recurve the timing and/or the cruise metering on the carb. The EGR allows for much leaner cruise with more advanced timing which helps MPG, NOx, HC, and doesn't do a thing to peak HP. I removed mine on a 454 and I lost 2 mpg and had to pull 4 degrees out of the vacuum canister and I fattened up the cruise mix the equivalent of two jet sizes on my Qjet.

[cboy]

I blocked mine off on my 81 351M with virtually no change...but then that motor is totally stock and produces little power to begin with.

[oldbogie]

Originally Posted by Fordy8man

im building a 1948 ford pickup with a 1984 351w motor. i want to clean up the look of the motor and wanted to know if i could do away with the egr valve or will it affect anything. the egr valve is mounted to a carb spacer. if i can do away with it i will put a new carb spacer on. not sure if its any help but its a 4bbl intake with a 4bbl holley going on it.
thanks tim

Ya know the things Detroit does gets really weird and EGR ranks right up there with the best of strange. I often think that the things the automakers did to meet emissions in the 1970s thru mid 80 was done in the hopes that POed customers would write their congressman to force the government to back off on emissions and fuel economy standards. There really can't be another reason for the approach that screwed things up so much.

So we all know that high compression engines will produce a fair amount of NOx, so if you put a little exhaust back in the incoming mixture the peak temps that form NOx will go down. But Detroit rather than fix their intake manifolds that were rather sloppy on feeding each cylinder what it needed, thus carburetion was jetted up to satisfy the leanest running cylinder and the rest ran rich and richer making excessive unburnt HCs their biggest problem. So instead of solving this problem with better design and execution, they went at it by retarding the timing, leaning the jets, and eliminating anything that looked like compression. Power went down, fuel efficiency went with it and operating temperature went so high that more NOx was formed than what came out of older high compression engines. Their solution was the EGR. Why not? Except for the EGR, all these other changes were the no cost solution to their problem, they just dumped this costly headache on the user. They got to fuel efficiency standards by making crappy little cars.

Basically it took a change of command in Detroit to get rid of their petulant response to emissions and fuel economy standards for them to suddenly rediscover the Ricardo "fast burn" combustion chamber and Bendix's electronic fuel injection that was sold to Bosch in 1960. Ford actually used the Ricardo chamber on the big Y block Lincoln and the smaller Y block Ford till 1955 when they saved themselves a few pennies on combustion chamber material and eliminated it for a simple bathtub with valves and a sparkplug. But even this was more effort at a low emissions, high efficiency combustion chamber than anybody else even attempted out of the gate.

Getting off my soap-box, if you put in a cam with some decent characteristics, bring the ignition timing into the 21st century, raise the compression, put on a good aftermarket intake, and take the time to trim out the carb of your choice, there's no reason why this engine won't run nice and clean with plenty of power and efficiency without an EGR.

Bogie

[pi71]

is egr the same as crankcase vent?,, with one side a breather,, and the other side egr? can i just run 2 breathers one on each side? ive got a 289, healthy cam,600cfm carb, headers,,,,,

[ernkazern]

No, they aren't the same at all. The vent, or PCV system, recycles crankcase vapors through the engine so they won't be released into the atmosphere. The EGR system allows exhaust into the intake stream to lower combustion temperatures, thereby reducing the creation of NOX.

[TMF]

And FYI, my '07 GT Mustang with the 3-valve 4.6 has eliminated the EGR completely. Correct tuning of the computer with fuel injection and bye-bye EGR!

John

[Chevrolet4x4s]

Finally(insert angelic harp music here)
Shane

[timothale]

I have heard of people taking the egr off a GM V6 and causing a problem because it upset the air fuel mix in the manifold. EGR 's on small block fords with 4 barrel carbs have caused a lot of engine fires. the egr spacer system concentrates a lot of heat at the back of the carb. the holly doesn't like heat the heat destroys the gasket an you soon ( 30 to 40 k miles) have an exhaust leak under the carb...if you continue to drive it's soon a BBQ'd engine The 4 barrel manifold egr contour will also leak if you remove the spacer plate the easiest way is to leave the spacer plate there and plug the holes or make a flat cover plate to replace the egr outlet inlet at the back. when the engine goes into a non smog inspection car I remove the egr retired ford engineer

[cefolar]

I am running the 4.6L DOHC modular motor in my 47 Ford and got an EGR block-off plate from the Detail Zone (www.detailzone.com). I haven't had any issues.

[Holder350]

Originally Posted by matt167

yup, anything over 2500* will produce NOX, EGR's open as vac goes down, drops the temps. new EGR's are calibrated to open when the temps require it, with the computer of course

EGRs open when vacuum is applied to them, whitch in most cases, is thru a thermal switch so the EGR doesnt open till the motor is warmed up to operationg temps.