Before doing anything with the carb after rebuilding, set the ignition timing. Then adjust the idle speed. Then fine tune the idle mixture with the mixture screws behind the plugs on either side of the main metering block. Once this is done, and if it has a sight plug in the passenger side of the primary bowl. pull that after killing the engine to see if fuel runs out of the hole. If it does, then you need to readjust the float height. Once you're satisfied how it runs, drive it a few miles putting it through it's paces. Then park it and pull a couple spark plugs from each side of the engine to see how the plugs look. It would help to install new plugs before doing all this. If the plugs come out white or gray, the fuel mixture should be OK and no changes to the jetting is necessary. If they're sooty, then you need to jet it down.. If so, go down at least 2 sizes, (numbers) or better yet, if sooty, go down 4 sizes. Then repeat running it and reading the plugs till they're grey. I would completely remove the EGR system if your local emissions testing allows it. EGR does NOTHING for fuel economy, nor performance. You gain nothing by introducing exhaust gases into the intake charge, you're only contaminating it and reducing performance (and using more pedal to make up for that, ergo, using more fuel to do the same work) Yea, a "malfunctioning EGR kills fuel mileage, but so does introducing exhaust gasses into the cylinders to start with. If you want to get the maximum fuel economy, then get rid of the EGR.

 

So to remove the EGR I've seen pictures of a plate bolted to the spacer plate in replacement of removed EGR or would I also remove the EGR spacer plate and then bolt the carb directly to the intake?

 

You need a spacer between the carb and intake. Not sure what you're intake flange looks like, but if the Exhaust gas is sourced from a hole in the flange beneath the carb, you need to figure a way to block those gasses off along with the hole. Sometimes you can use an older style PCV spacer under the carb, but you may need a thin solid plate under that to keep from having a vacuum leak. A solid phenolic spacer would be best to insulate the carb from the heat, but if there's an EGR hole in the intake it needs to be covered with a metal plate (steel, aluminum will burn or corrode through over time), in any case the hole needs to be sealed.

 

My vote would be to keep the EGR. I agree race cars probably don't have EGR but that's a different application than rolling a motor home down the freeway at 60 mph.

The EGR comes into play while your cruising along nice and easy. It's not open at idle or under heavy throttle.

Something has to fill up those 460 cubic inches so instead of drawing all that air through the carb (mixing with fuel) inert exhaust gases are introduced to make up part of the volume which leans out the mixture.

Because the exhaust gasses are inert and don't burn the EGR also helps with engine cooling.

Because the mixture is so lean, the timining can be fully advanced. So cruising down the freeway at 60 mph under a light throttle, exhaust gasses are being recirculated, cutting down on the volume of air being pulled through the carb (and mixed with fuel), and your vacuum advance is all in.

What so often happens on a 460 when the EGR is eliminated is they might run a little hotter and they might develop spark knock (or pinging) because the timing is now too advanced for the richer mixture... so the timing get retarded to eliminate the spark knock and you end up losing power and economy.

So if your going to remove EGR you may need to recurve your distributor to compensate. Retarding base timing to eliminate the pinging caused by the EGR removal will only work against you.

In my opinion the key to maximum power and economy on these old 460s is running as much ignition advance as you can safely get away with.

 

well if you put lipstick and a fancy dress on a Pig it is still a Pig...EGR is chit that belongs in the garbage ...along with Air pumps and the like....this I s what I think and I will not comment further.....https://www.summitracing.com/int/par...illocation=int
https://www.summitracing.com/int/sea...illocation=int
And do the Igntion upgrades I suggested before....OR go like Me....
https://www.summitracing.com/int/par...-350-econoline

 

You're not going to get spark knock from a rich mixture. That WILL happen under a lean condition, which also creates more heat in the cylinder. And it's a death sentence to pistons. It's the LAST thing you want to see happen in an engine lugging a heavy vehicle. There's already enough heat being generated in this application, you do not want more created from a lean condition. That's a sure way to melt a piston in an engine lugging a motorhome. About the only time that engine in a motorhome will not be lugging the vehicle is on a downhill grade or on flat ground with a tailwind and that's rarely going to happen. In all other conditions, you're gonna be burning fuel to keep it rolling. There's no way introducing hot exhaust gasses into the intake charge will result in a cooler mixture. And it's not going to decrease the engine's demand for fuel. EGR gasses are not inert. They're made up of burned and some unburned fuel plus CO2 and CO. How much of each depends on how well the engine is tuned. You're going to burn as much fuel as it requires to keep the vehicle rolling at the speed the driver demands. How much fuel is required depends on how efficient the engine is to start with. And it's not going to be at it's maximum efficiency by introducing dirty exhaust gasses into the intake charge. And "race cars" probably don't have EGR ? Really ? None I've ever seen had an EGR system. EGR systems were only created to try to meet emissions standards created by government bureaucrats, they were never created to maximize fuel economy.

 

The EGR debate has been going on for a long time. For the record I have no religion one way or the other but I have looked into it. My only interest here is to help keep old Fords trucking and learn what I can from others along the way.

There are lots of good threads on ERG and here's one I found with a quick search. From what little I read it started out innocently enough but quickly turned into a heated debate.

Your mileage may vary... Lol!

https://www.ford-trucks.com/forums/1...s-mileage.html

 

Shackmasterchris, that is heinous gas mileage, even for an old 460. I got 6.5 mpg from my 82 E-350 motorhome using a Carter carb. Didn't matter if I was going uphill, downhill, with a tailwind, I pulled about 6 mpg.

I'd recommend an Edelbrock 1411 750 cfm carb with electric choke. Bolt that on for some better mileage. They are easier to work on and tune than Holleys, and with the electric choke they'll help start your van in the winter. Whenever I tried to rebuild carbs, I always ended up with a few extra parts left over. The Edelbrock is going to be set up good right out of the box unless you live on top of a mountain somewhere in Nepal.



Performance Carburetors and Accessories - Performer Series Carburetors - Edelbrock, LLC.

 

how is a Carter easier than a Holley to tune?

 

If the original poster asked this question, I'd answer. Sounds like you are just picking a fight. And I said Edelbrock is easier than Holley, not Carter.

 

No. I just know that Holleys are gravy to tune.

 

Yea, I'd like to know that too. Edelbrock/Carter = same thing. These are the carbs that guys who don't learn to tune a Holley to start with go to when the give up.

 

Really ! ? Says who ?

 

I'm aware that Carter = Edelbrock (both made by Weber; Carter sold design to Edelbrock). You've just proved both my points. Why do I even bother to post sometimes?

 

Just thought I'd add a few comments about carburetors, the 460 engine and motorhomes. Details have been posted a few months ago in a separate thread. When I purchased my 1982 24 ft. Class C, I was plagued with poor mileage, severe vapor lock and lousy performance. One of the first things I did was to replace the intake manifold to get away from the 4180 and added an Edelbrock 1411 on the advice of Edelbrock Tech Support. After several other modifications including timing, ignition mods, cold air intake, EGR removal and header addition I was getting 10 mpg on level freeway at 55 miles per hour, at sea level, 78 F and cruise control. Trip average actual was 8.4 to 8.9 mpg over 3,800 miles. But I still wanted more! Performance was stately and my wide-band AFR still suggested I could still lean out the cruise parameters. I had become convinced that the 750 cfm 1411 was too much carb for my use. My engine usually operated between 2200 and 3500 rpm, and never went over 4500. Fortunately, there is a highly respected carburetor engineer (Competition Carburetor) local. So I went for a detailed discussion. Bob agreed completely that a 600 cfm carb was the best solution for this application. Further he pointed out that the 1411 was a bored out version of the 1406 and as a result, the venturi signals on the 1411 were very weak in comparison. For motorhomes he advocated the Edelbrocks because there were no rubber based components (Holley Power Valve) to fail by backfire or other modes. He emphasized long term reliability given the ridiculous service accessibility of the E350 engine compartment. I then had him do a complete carb tune to the operating specs of my engine and application. 4 weeks later, I bolted on the custom tuned 1406 and the results were amazing. The engine came alive, the response and performance was actually aggressive! The cruise AFR went 0.2 points leaner than with the 1411. Winter interrupted fuel economy tests, but thus far in town I seem to have picked up between 8 and 11%. So for what its worth, I'd advocate the Edelbrock 2166 manifold, the 1406 carb and a possible custom tune. Recurved distributor and cam timing set to +2 degrees will also really help.