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Replace EGR Carb Spacer with Non EGR Spacer

 
Gregski
Enthusiast
Posts: 475
Joined: 03/10
Posted: 04/13/10 08:19 PM

If I am not concerned with SMOG and emissions can I replace the mid '75's EGR carburetor spacer I have now with an early '71 style non EGR one, or better yet do I need a spacer at all?

My Motorcraft 2150 carb has a PCV port on the base of it, so I placed the carb on the intake manifold without any spacers and I did not have any clearance problems. I did google carb spacers and I guess they serve a purpose other than giving you an inch of height, but I figure I ask you anyways if I need one. I figure with it I can have leaks between the carb and the spacer as well as between the spacer and the intake manifold, so I am thinking why not just eliminate it all together.

Again I am new to this car stuff so please be gentle. Pictures below:

96149D1271207838 Replace Egr Carb Spacer Non Egr Spacer Egr Spacer 1

96150D1271207838 Replace Egr Carb Spacer Non Egr Spacer Non Egr Spacer 1  

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mechanicalguy48
Guru
Posts: 854
Joined: 12/07
Posted: 04/14/10 09:26 PM

If you remove the spacer the carb will be exposed directly to manifold heat. Most carbs need the spacer to help in hot idle situations to keep the idle from degrading. Spacers should be used with the thick gasket also. The spacer shown there has a balancing slot which is fine but when you use it with a thick gasket it will eat away the gasket where its exposed at the balancing slot there, so its probably better to trim it for that spacer. By the way, the old spacer was fine and looked emission ready, you cant tell if the egr valve is working or not, simply unplug and seal the vacuum line to the egr valve and no egr,,,, no real reason to replace it with a different spacer which may or may not seal correctly.  

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waynep7122
Guru
Posts: 774
Joined: 01/10
Posted: 04/15/10 04:12 PM

i agree...    take the spacers off..   you will notice a big hole under the spacer.. this is open to the exhaust stream...

this is where the EGR valve gets it's exhaust flow..

you have several choices..    remove the egr and install a home made block off plate onto the back of the adaptor..

cut off the back of the adaptor.. and have a welding shop weld up the openings..   if the passages are round.. or close to round..   you might tap them for a pipe plug.. and plug them..

you will have to use the specified adaptor to manifold gasket...  


you have to understand.. on most fords with spacers.. the carb mounting gaskets line up like this..


carb

carb to adaptor gasket

adaptor

adaptor to intake gasket..

intake manifold..


here is a picture of the proper 1975 adaptor to intake gasket..

http://contentinfo.autozone.com/znetcs/product-info/en/US/fpr/60244/image/8/

fel pro #60244


here is a better picture that shows both the upper and lower gasket..

http://contentinfo.autozone.com/znetcs/product-info/en/US/fpr/ES70582/image/8/

you can really see the difference..  the opening on the gasket on the left has exhaust gasses..  

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mechanicalguy48
Guru
Posts: 854
Joined: 12/07
Posted: 04/15/10 05:59 PM

Why would you go to all the trouble of welding/plugging/blocking off when if you simply cut off vacuum to the egr valve- it cannot open. You will have a hot idle problem without the spacer.  

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Gregski
Enthusiast
Posts: 475
Joined: 03/10
Posted: 04/15/10 09:22 PM

thanks for your input, here's a link to more pictures of the spacer

Small Block Ford 302 V8 Carb Spacer  

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Gregski
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Posts: 475
Joined: 03/10
Posted: 04/19/10 12:03 AM

"If you remove the spacer the carb will be exposed directly to manifold heat."

Thank you for the reply and the explanation.  Can I ask a follow up question regarding your comment about the heat.  That's the part that confuses me if the spacer is there to keep the heat away from the carb then why in the world are the hot exhaust gases being pumped through it from the heads through the intake manifold into the spacer around the EGR vavle and back through the spacer? Makes no sense to a newbie like me, if you want a cooler carb and you put a spacer beneath it to distance it from the hot engine, then why warm up the spacer? Do you see my dilema, can you explain that logic to me?  

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Gregski
Enthusiast
Posts: 475
Joined: 03/10
Posted: 04/19/10 12:04 AM

"... take the spacers off... you will notice a big hole under the spacer.. this is open to the exhaust stream... this is where the EGR valve gets it's exhaust flow..."

Honestly I did not realize there was an opening in the intake manifold that let the exhaust gases into the spacer from below, that's why I am here on these forums, I'm learning, I though the exhaust gases were pumped into the carb via a small metal tube that feeds off of the passenger side exhaust manifold.

So on the 1971 Ford Econoline van with the 302 engine that I got this spacer from at the junk yard did the exhaust gases always pump into the intake? What's the harm in that? I mean isn't that what happens when the EGR valve is opened?  

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Gregski
Enthusiast
Posts: 475
Joined: 03/10
Posted: 04/19/10 12:08 AM

Icon Quotemechanicalguy48:
Why would you go to all the trouble of welding/plugging/blocking off when if you simply cut off vacuum to the egr valve- it cannot open. You will have a hot idle problem without the spacer.

Two reasons:

1.  Since I am a newbie I had no idea there was a hole in the intake manifold under the carb spacer that exhaust gases entered the spacer through.  I thought exhaust gases came from a metal tube coming from the passenger side exhaust manifold into the top of the carburetor.  So I didn't understand all of that and thought it was going to be simple replacement.

2.  Asthetics mostly, I don't like the two mushrooms that sit behind the carb, aka the EGR valve and the back pressure valve.  Plus all those extra vauum hoses, yuk!  

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mechanicalguy48
Guru
Posts: 854
Joined: 12/07
Posted: 04/19/10 08:40 AM

Yeah, you are correct about hot exhaust gases, but even in a non egr manifold there is an exhaust crossover to warm the intake so that you dont get carb icing. Some performance manifolds do away with the crossover. The exhaust gases do not pump into the intake but are metered by the EGR valve. The exhaust gases are essentially "inert" and what they do is get in the way of combustion and therefore hinder peak pressure. Sounds bad ,,,, and it is, but its a way to control NOx formation. NOx compounds are formed at high peak pressures so the EGR gases keep the pressures down. They also act to control spark knock in a perverse way,,, in that if you shut off EGR you may see spark knock using the same carb and spark curve that worked fine before. The reason is you no longer have that inert gas in your combustion chamber and peak pressure goes up along with power and tendency to knock. I can understand your aesthetics urge, but I think if it was me I would get an earlier non egr manifold or perhaps a four barrell manifold to put on there for a cleaner look. If your new plate covers the EGR hole and seals it,,,,fine.  

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Gregski
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Posts: 475
Joined: 03/10
Posted: 05/21/10 11:29 PM

What's with me and mud?  So today I went to our local Pick-n-Pull aka junkyard and I found this 1973 Ford F-Series truck with a two barrel carb and a spacer with no hoses going to it and no EGR valve.  Sweet I thought maybe this spacer will work for my EGR deletion on my 76, so I pulled it off.  Then I flipped the spacer over and found dirt/mud under it, what the heck I thought, man it was cracked, no good.  I bought some other parts and asked if I could have this spacer for free, they said no, but reduced the price to $4.00 bucks, so I bought it just for the he11 of it since the bottom is different from the two I already have so this type would not draw exhaust gases all the time into the intake.

Can any of you identify the carb from this picture, I couldn't see a label on it?

73Truckcarb

73Truckspacer1

73Truckspacer2  

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mechanicalguy48
Guru
Posts: 854
Joined: 12/07
Posted: 05/22/10 09:07 PM

Its a 2100 2V carb. Venturi size should be stamped on the carb body, they vary.  

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Gregski
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Posts: 475
Joined: 03/10
Posted: 05/25/10 08:23 PM

Here are the three spacers I accumulated from junk yards.  They look similar but the two smaller ones have a base plate that is narrower from front to back they are 3 inches by 5 1/4 inches, the big one which is what came on my engine measures 3 1/4 inches front to back and 5 1/2 accross.  So when I use one of the two smaller ones there is a small gap between the spacer and the carburetor.

At this point I am thinking of keeping my original spacer and fabbing a EGR block off plate, no big deal, but I wanted to use the spacer in the middle without the nipple for a clean look since my 2150 Motorcraft 2 barrel carb has the PVC nipple on its base already.

I'm sharing the pictures and part numbers to help someone else down the road.

LEFT: D2TE-9A589-BA (but the year stamped in the circle says 71)

MIDDLE: no part number (but the year stamped in the circle says 72)

RIGHT: D50E-9A589

Carb%20Spacers%201

Carb%20Spacers%202  

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Gregski
Enthusiast
Posts: 475
Joined: 03/10
Posted: 06/04/10 09:25 PM

Since non of the non EGR carburetor spacers would work with my EGR manifold I decided to make an EGR block off plate out of 1/4 inch thick piece of steel I found in the garage, probably overkill but less cutting. Please note the different bolt sizes, I have no idea why Ford did that, but one is bigger than the other.

EGR%20Plate%201

EGR%20Plate%202

EGR%20Plate%203

EGR%20Plate%204

EGR%20Plate%205  

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