Ford 94 equalizer valve

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Oldog3

Junior Member
I am rebuilding 94's and the kit came with 2 ECONOMISER valves . I am trying to figure which one to use , on the left is the equalizer valve that came out of the carb I am rebuilding and the TOP looks the same as the one on the far right however the BOTTOM looks the same as the middle one

The middle one is the same depth as the one I took out .

Everything is telling me the middle one is correct but as this is my first rebuild try , my confidence is telling me to ask why this is correct as I have 3 more to do

Thanks
Dan
 

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Thanks jack , I also called it the wrong thing ...it is an ECONOMISER valve

Spark control ??? could you give me the condensed version ?
Thanks
Dan
 
Dan, I agree with Jack, but with one consideration: The gasket surface must be flat, as is that surface on your old valve. Some guys chuck it into a lathe for modification, but I've also heard that the use of two gaskets may work also.

Another consideration would be the vaccuum opening value of the new valve if used on a multi carb setup. Lower vaccuum in the system would have a normal valve opening way too soon.
 
Alan , I do have a vacuum line hooked up to that carb , but I pick it for convenience there was no rime or reason to it, on the original setup it was hooked the carb right behind it .
I had these up and running and everything seemed to running smoothly [ in place , snow keeps it off road for now ] I am rebuilding because of a leak

Thanks !
Dan
 
Dan, I wasn't referring to a vacuum line. The economizer valve senses the vacuum in the carburetor and opens to provide more fuel when you punch the throttle, which lowers the vacuum. A multi carb setup would have lower vacuum, so the value required to open the valve would need to be lower as well.
 
You have got to be careful with Holley economizer (power) valves. Although the later valves for 4BBL's will physically screw into a 94 body, as 38V8 says, the mounting surfaces are different and they can leak. As he says, you can machine them to fit, or get the proper ones. Also be careful of using two gaskets there is very little clearance between the base and the opening on the power valve. I had a 94 with an odd power valve that wouldn't run right even after a rebuild. I finally found that the power valve was too "thick" (high), and the opening pressed on the base when the carb was assembled, essentially shutting off the vacuum source for the valve. I found this when I set the body (with power valve) on the base without a gasket and the body actually rocked on the base. These days, when I rebuild a 94, I leave the top off and put a little gas in the float bowl and leave it overnight to make sure it doesn't leak. I have had more power valve problems with these carbs than all other areas put together.
 
38v8 ,
When I mentioned the vacuum line I did so only in the context that there was no line to that carb on the original set up .... as this carb seemed to leak , could the now present vacuum line be the cause ?

Tunman , I will do this test with the gas in the bowl / top off ..

I am still trying to figure the "spark control valve" angle that Flatjack speaks about above , do both you and 38v8 concur that the valve on the far right is the correct one to use ?

Thanks !!
Dan
 
Notice the 2 rings on the mating surface of the PV on the far left (the "original")? The one on the right does not have them. The PV on the right is more correct than the "spark valve" (obviously), but the pictures are not detailed enough to say for certain that the one on the right is absolutely correct. I will say that some of rebuild kits for 94's I have purchased recently came with later (4BBL) PV's.
 
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Old,
Jack is correct....whose asking me....anyway....what the guys have said
I concur with 110%. I much prefer the power valves that Daytona Parts sell. The
Daytona PV are a proper copy of the originals. The square fuel escape ports in
the PV shown can be/ sometimes are leakers. The Daytona PV's feature the same
escape ports as the originals and that is significant.. Regardless of the source I
strongly recommend refacing the gasket face to insure flatness and squareness to
the threads. I'm so anal on my 94 rebuilds that I make my own PV gaskets....
Charlie ny
 
Oldog3 said:
38v8 ,
When I mentioned the vacuum line I did so only in the context that there was no line to that carb on the original set up .... as this carb seemed to leak , could the now present vacuum line be the cause ?

Tunman , I will do this test with the gas in the bowl / top off ..

I am still trying to figure the "spark control valve" angle that Flatjack speaks about above , do both you and 38v8 concur that the valve on the far right is the correct one to use ?

Thanks !!
Dan
Click to expand...



The one on the right is the correct economizer (power valve). The other two are actually both spark valves. Just slightly different stye/manufacturers. If you look at all of them, you will see that the spark valves are spring loaded in the opposite direction from the economizer. Another way to tell them apart.

Sal
 
Old,
Another thought here......After you complete the rebuilds install each carb
separately on a decent running motor and dial each in. Set the mixture ( tach or
vac gage or both ) and the idle speed. As part of this procedure slowly turn each
mixture screw in , ONE AT A TIME, until the engine dies. If doing this does not cause
the engine to die you can bet the bank roll you have an internal fuel leak. If you
choose to omit this step you risk a sort of agonizing chase your tail all over the place
in a vain attempt to devine which carb/s are causing the overly black exhaust to
spew from your vehicle.
Charlie ny
 
tubman said:
Notice the 2 rings on the mating surface of the PV on the far left (the "original")? The one on the right does not have them. The PV on the right is more correct than the "spark valve" (obviously), but the pictures are not detailed enough to say for certain that the one on the right is absolutely correct. I will say that some of rebuild kits for 94's I have purchased recently came with later (4BBL) PV's.
Click to expand...

Tubman ,
I am posting another picture of what I have , not that I am trying to beat this subject to death but because I am really learning something here and after looking at the bases shone here they are different
Thanks !
Dan
 

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I am with the others in saying that the one on the right is an economizer valve. It looks too tall for the 59 and earlier models. Check for interference between the body of the bowl and the threaded portion of the valve. There should be a recess cast into the bowl for the valve and the valve should not touch the body.

The economizer valve need vacuum to close it, it is normally open. In a multi-carb setup, the vacuum supplied to the valve may be too low to keep it closed, giving you a very rich mixture. The rating of the valve should be stamped on the face of the valve, not the side that you show in your last photo.

The spark control valve is used to give ported vacuum to the vacuum advance on the distributor. If you are using the 8BA type distributor, you need the 8BA type carburetor and the spark control valve.

I agree with buying the Daytona Carburetor kits as the parts are very good quality and you can specify the power valve that you need for your application. With their power valve, you should use the gasket with the triangle shaped cutout and tighten it finger tight plus 1/6 turn. Fill the bowl with gas and let it sit over night. If the gas leaks past the gasket, tighten another 1/6 turn and retest. If this does not seal the leak, you need to look at the condition of the carburetor body.

Here is a link that explains the selection of a power valve.

http://forums.holley.com/entry.php?430-Holley-Power-Valve-Tuning
 
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Old,
I wish to clarify something here.......the two brass screws at the rear of the carb, on the base, are IDLE mixture screws and not mixture screws. Once the carb is
off idle the effect of this adjustment drops off rapidly.
Not meaning to horn in here but the one on the right is what FLATJACK says
it is the.........economizer/vac operated power valve.
c'est tout,
Charlie ny
 
"The economizer valve need vacuum to close it, it is normally open. In a multi-carb setup, the vacuum supplied to the valve may be too low to keep it closed, giving you a very rich mixture. The rating of the valve should be stamped on the face of the valve, not the side that you show in your last photo."

"The spark control valve is used to give ported vacuum to the vacuum advance on the distributor. If you are using the 8BA type distributor, you need the 8BA type carburetor and the spark control valve."



Just a couple of things I disagree with. I know a lot of people say that the power valves need to be for a lower vacuum rating if you have dual or tri power setups. Manifold vacuum is a sign of engine load from idle (high vacuum) to Wide open throttle (very low vacuum). If the vacuum is low, that means a heavier load and you need the richer air/fuel ratio. The exception to this is when using an aftermarket cam with more overlap and less manifold vacuum. Then you would need to put in a lower vacuum rated power valve.
Also, OEM power valves back in the day were stamped on the side with the vacuum rating.

Also, carburetors on 8BA engines did not have a spark valve. They were still loadomatic ignition systems, but did it without the spark valve. The 1954 through 1956 Y-Block V8's used a spark valve on these carbs.

Sal
 
Charlie ny said:
Old,
I wish to clarify something here.......the two brass screws at the rear of the carb, on the base, are IDLE mixture screws and not mixture screws. Once the carb is
off idle the effect of this adjustment drops off rapidly.
Charlie ny
Click to expand...

I have an air/fuel meter in my truck, and have been surprised at the effect of idle mix screws on cruise AFR. If set for best/smoothest idle, cruise economy suffers. To get the best cruise AFR, I have them set out maybe 1/16 turn from where I get an occasional stumble at idle.
 
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