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Vacuum port on Holley 4160??

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Vacuum port on Holley 4160??

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Old 05-25-2009, 07:22 PM
  #11  
19stang66
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Yes you are correct in saying that my engine ran like sh*t. But that is also due to the fact that the rubber fuel line was kinked before the fuel pump

So what's the difference between using the bottom nipple for "full manifold vacuum" or the upper nipple for "ported manifold vacuum"??
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Old 03-29-2014, 05:48 PM
  #12  
my68ride
 
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Default vacuum port at base of carb

The vacuum line from your automatic transmission would go there
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Old 03-30-2014, 11:24 AM
  #13  
2+2GT
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Well, It could go there, but the factory connection for the trans was the rear manifold fitting. That carb fitting is very convenient for connecting the manifold vacuum part of the Distributor Vacuum Control circuit, but again, since the 4160 was not a factory installation, Ford connected it elsewhere.

For example, the "red stripe" hose could be connected to that port-

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Old 03-30-2014, 06:33 PM
  #14  
barnett468
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Originally Posted by 19stang66 View Post
So what's the difference between using the bottom nipple for "full manifold vacuum" or the upper nipple for "ported manifold vacuum"??
This is a complicated and sometimes contentious issue, lol.

The bottom front fitting is full time manifold vacuum. Do NOT use it for your distributor or trans.

The top side fitting has supposed to have virtually 0, nada, zilch vacuum at idle. I has vacuum just a hair above idle.

If it has vacuum at idle you have a problem. Tell us and we can tell you how to easily fix it.

Last edited by barnett468; 03-30-2014 at 06:35 PM.
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Old 03-31-2014, 01:47 AM
  #15  
Gun Jam
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Whats ****ing complicated is why my68ride would reply to a 6 year old thread...yeah its great you want to help this guy but im not sure how this even happend....

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Old 03-31-2014, 03:00 AM
  #16  
barnett468
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Originally Posted by Gun Jam View Post
Whats ****ing complicated is why my68ride would reply to a 6 year old thread...yeah its great you want to help this guy but im not sure how this even happend....

-Gun
Ahhh, ha, ha. That's funny. I didn't see that.
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Old 03-31-2014, 10:09 AM
  #17  
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Default 6 year old thread

I answered a 6 year old thread??? I was looking for a Holley carb. part and I guess that question popped up. Stupid computers! I changed my 289 for a 302 with aftermarket intake manifold and Carb, so that is where I had to connect my trans vacuum......didn't know it was a 6 year old thread and don't even know how I ended up on Mustang Forms.
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Old 03-31-2014, 12:29 PM
  #18  
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For whats its worth there is somewhat of debate between running a vac advance dizzy off of full manifold vac OR ported vac.

distributor manufactures will always tell you to run ported vac.

However there is a following of individuals that have good success running full manifold vac on there distributors.

I have tried both and I found that running full manifold vac caused the exhaust to smell rich and unburned despite allowing me to run idle mix a full air fuel ratio point higher than I could with ported vac. Im thinking this is due to reduced exhaust gas temps in the headers not fully burning off the exhaust.

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Old 04-02-2014, 01:00 AM
  #19  
barnett468
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you might know this.

the ported and manifold vac are exactly the same above around 1/8th throttle opening.

there is basically no ignition advance from the vacuum under hard acceleration.

the sole purpose of dist vac is to improve mileage.

in california you must have the original smog equipment in place even if your car passes the tailpipe test.

on the old cars they check the emissions at idle and cruise but only use one reading.

calif smog is stupid, lol.

Last edited by barnett468; 04-02-2014 at 01:07 AM.
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