Distributor Advance

  #1  
Old 12-07-2015, 09:37 AM
avellaneda13's Avatar
avellaneda13
avellaneda13 is offline
Junior User
Thread Starter
Join Date: May 2013
Location: Kernersville, NC
Posts: 60
Likes: 0
Received 1 Like on 1 Post
Distributor Advance

Is this were the distributor advance hooks up if not then where?

 
  #2  
Old 12-07-2015, 12:40 PM
1986F150six's Avatar
1986F150six
1986F150six is offline
Lead Driver
Join Date: Jul 2009
Location: Sheffield, AL
Posts: 6,477
Likes: 0
Received 15 Likes on 14 Posts
That port appears to be below the throttle plate, which would mean that it is to manifold vacuum. On most 70s and up vehicles, the distributor advance is factory set to be triggered by port vacuum. Using a vacuum gauge, check to see if that port has vacuum at idle speed.
 
  #3  
Old 12-07-2015, 01:30 PM
The Frenchtown Flyer's Avatar
The Frenchtown Flyer
The Frenchtown Flyer is offline
Fleet Mechanic
Join Date: Nov 2002
Posts: 1,638
Received 61 Likes on 49 Posts
Some ported taps have some vacuum at idle speed - maybe 5"hg.
 
  #4  
Old 12-07-2015, 01:37 PM
1986F150six's Avatar
1986F150six
1986F150six is offline
Lead Driver
Join Date: Jul 2009
Location: Sheffield, AL
Posts: 6,477
Likes: 0
Received 15 Likes on 14 Posts
Yes, Sir... the one on the 1970 Carter YF from a 1970 F350, which I use on my 1986 F150, has about 5" @ idle and does not go above approximately 11" at any speed.
 
  #5  
Old 12-07-2015, 02:35 PM
avellaneda13's Avatar
avellaneda13
avellaneda13 is offline
Junior User
Thread Starter
Join Date: May 2013
Location: Kernersville, NC
Posts: 60
Likes: 0
Received 1 Like on 1 Post
so was that a yes or no?
 
  #6  
Old 12-08-2015, 09:48 AM
1986F150six's Avatar
1986F150six
1986F150six is offline
Lead Driver
Join Date: Jul 2009
Location: Sheffield, AL
Posts: 6,477
Likes: 0
Received 15 Likes on 14 Posts
Originally Posted by avellaneda13
so was that a yes or no?

First, using a vacuum gauge, determine if there is a vacuum signal from that port at idle speed. If there is no vacuum at idle and vacuum is measured as soon as the speed is raised, that is the correct port for ported vacuum, which is what the factory used, originally.

If that port has vacuum all the time, it can be used, but adjustments to idle speed likely will be required.

I use a Carter YF carburetor from a 1970 F350 and it only has one vacuum port. The vacuum at that port is ~5" Hg @ idle and never gets higher than ~11". It did not allow maximum vacuum advance at the distributor, so it was capped and I use manifold vacuum for the distributor advance.
 
  #7  
Old 12-09-2015, 04:35 PM
roadrash63's Avatar
roadrash63
roadrash63 is offline
Elder User
Join Date: Jun 2009
Location: nw pa.
Posts: 907
Likes: 0
Received 5 Likes on 3 Posts
Originally Posted by 1986F150six
Yes, Sir... the one on the 1970 Carter YF from a 1970 F350, which I use on my 1986 F150, has about 5" @ idle and does not go above approximately 11" at any speed.
Thank you !
I was running ported advance and could not get going faster than 68 !
And I was wanting more power.
When I read about your ported carb vacuum limiting to 11 hg.
I switched to manifold vacuum and was able to reach 80 !
Not that I do this all the time.
Better throttle response at all speeds.
The only negative is the is a small miss at idle now...
 
  #8  
Old 12-10-2015, 09:44 AM
1986F150six's Avatar
1986F150six
1986F150six is offline
Lead Driver
Join Date: Jul 2009
Location: Sheffield, AL
Posts: 6,477
Likes: 0
Received 15 Likes on 14 Posts
With manifold vacuum, the distributor is advanced @ idle, where as with ported vacuum, the vacuum advance is not activated or is, just a little.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
KRinAZ
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
18
08-29-2017 07:01 AM
Codeseven
Fuel Injection, Carburetion & Fuel System
3
07-05-2016 02:41 PM
oldmerc
1948 - 1956 F1, F100 & Larger F-Series Trucks
19
05-01-2016 07:37 AM
rashanny
1948 - 1956 F1, F100 & Larger F-Series Trucks
3
08-14-2011 09:44 AM
kking1977
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
8
04-26-2003 04:31 AM


Thread Tools
Search this Thread
Quick Reply: Distributor Advance



All times are GMT -5. The time now is 03:15 AM.