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Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: moparx] #2917988 05/03/21 12:06 PM 05/03/21 12:06 PM
Joined: Jan 2004 Posts: 8,233 fredericksburg,va C cudaman1969 master
cudaman1969 master C Joined: Jan 2004 Posts: 8,233 fredericksburg,va	Originally Posted by moparx i'm not going to start a debate here. everything was ported up to around 74ish [?], then, if i REMEMBER correctly [???] there were trees on the rear of the intake manifold that went to a vacuum "enhancer", then to a temperature sensor in the water pump housing, then to the carb, then to the distributor and vacuum pots controlling the air filter snorkel flaps. i just looked at a 440 out of a 78 newyorker, and a 400 from a 76 newport [both with thermoquads] that are on my shelf, and that is the way they have the myriad of vacuum hoses ran. they were this way when removed, and i just left everything as was just to keep the holes plugged. i "think" this started in 74, because i remember the round multi-port "vacuum enhancer" on the china wall of my wife's 74 charger with a 400/727 combo. remember, this is for the big blocks. i don't remember, nor have, any small blocks to compare. so manifold through temperature [wax pellet] senders to ported. i don't know what this setup could be correctly categorized. Still ported vacuum not straight, all those connections were used so engine got to operating temp first. Look at the advance ‘can’ on a mopar distributor. They ALL pull the plate in the timing advance direction so IF it’s manifold ported it would be in wrong direction, give it gas it drops, let off it advances, backward! Chevy was like that, had one, 70-1/2 Z28

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: cudaman1969] #2918014 05/03/21 01:18 PM 05/03/21 01:18 PM
Joined: May 2019 Posts: 6,217 nowhere S Sniper master
Sniper master S Joined: May 2019 Posts: 6,217 nowhere	Originally Posted by cudaman1969 Still ported vacuum not straight, all those connections were used so engine got to operating temp first. Look at the advance ‘can’ on a mopar distributor. They ALL pull the plate in the timing advance direction so IF it’s manifold ported it would be in wrong direction, give it gas it drops, let off it advances, backward! Chevy was like that, had one, 70-1/2 Z28 Pretty sure you don't know the difference between manifold vacuum and ported vacuum. Also pretty sure you don't understand why vacuum advance is used.

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: Sniper] #2918027 05/03/21 01:38 PM 05/03/21 01:38 PM
Joined: Jan 2004 Posts: 8,233 fredericksburg,va C cudaman1969 master
cudaman1969 master C Joined: Jan 2004 Posts: 8,233 fredericksburg,va	Originally Posted by Sniper Originally Posted by cudaman1969 Still ported vacuum not straight, all those connections were used so engine got to operating temp first. Look at the advance ‘can’ on a mopar distributor. They ALL pull the plate in the timing advance direction so IF it’s manifold ported it would be in wrong direction, give it gas it drops, let off it advances, backward! Chevy was like that, had one, 70-1/2 Z28 Pretty sure you don't know the difference between manifold vacuum and ported vacuum. Also pretty sure you don't understand why vacuum advance is used. Pretty sure you’re an a$$, I know exactly what I’m taking about. Do YOU know what manifold vacuum is? Do you know what carb port ABOVE and BELOW the throttle plate is? Last edited by cudaman1969; 05/03/21 01:39 PM.

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: cudaman1969] #2918128 05/03/21 06:37 PM 05/03/21 06:37 PM
Joined: Jun 2014 Posts: 1,321 VA D dragon slayer pro stock
dragon slayer pro stock D Joined: Jun 2014 Posts: 1,321 VA	Originally Posted by cudaman1969 Originally Posted by NANKET Short answer is yes there is a ported vacuum connection on carbs before 67. I have a 62 383-2bbl, and a 62 413-4bbl both have it done in rubber hoses. 1960 413-4bbl has it with a hard steel line. Not for distributor advance Your not serious are you? So what is it for if not distributor? I don't know why you would trash a thread for kicks with mis-information, clearly you are wrong in your statement. But why? That 66 hemi of yours has ported for the distributor.

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: dragon slayer] #2918172 05/03/21 07:56 PM 05/03/21 07:56 PM
Joined: Jan 2004 Posts: 8,233 fredericksburg,va C cudaman1969 master
cudaman1969 master C Joined: Jan 2004 Posts: 8,233 fredericksburg,va	Trash the post huh! Well let’s see, The ignorance on here is astounding. I’ll make this as simple as I can. ANY ‘port’ above the throttle blade goes to distributor, PORTED VACUMN, Any port under the throttle blade is MANIFOLD vacuum, and goes to something beside the distributor. If your not at least 70 you didn’t live first hand with this stuff like I did. When you work for Dodge you get to go to all their tech schools and I went to learn from the experts. Done

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: cudaman1969] #2918205 05/03/21 09:28 PM 05/03/21 09:28 PM
Joined: Jun 2014 Posts: 1,321 VA D dragon slayer pro stock
dragon slayer pro stock D Joined: Jun 2014 Posts: 1,321 VA	That is not what your post were saying so.....the confusion of your post. The Master training lectures are on the web so any one can look them up. Once the throttle blade is opened the ported position to the distributor is activated and the vacuum at that port is almost the same as the manifold vacuum off the intake, or the PCV port at the back of the carburetor. Basically an on off switch to prevent any vacuum advance from being applied at idle with throttles closed and high engine vacuum. So as stated Chrysler used the ported (Vacuum Spark Port) on the carburetor for the distributor vacuum advance. The vacuum advance was used to adjust timing to account for the motor load, while the mechanical advance account for the speed of the motor. Carters only had one vacuum port sized for the distributor. Holley's did have more on the throttle plate, but as far as the time frame discussed predominantly Carter AFB and AVS for the 4 barrel cars as explained above.

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: cudaman1969] #2918306 05/04/21 08:15 AM 05/04/21 08:15 AM
Joined: May 2019 Posts: 6,217 nowhere S Sniper master
Sniper master S Joined: May 2019 Posts: 6,217 nowhere	Originally Posted by cudaman1969 Originally Posted by Sniper Originally Posted by cudaman1969 Still ported vacuum not straight, all those connections were used so engine got to operating temp first. Look at the advance ‘can’ on a mopar distributor. They ALL pull the plate in the timing advance direction so IF it’s manifold ported it would be in wrong direction, give it gas it drops, let off it advances, backward! Chevy was like that, had one, 70-1/2 Z28 Pretty sure you don't know the difference between manifold vacuum and ported vacuum. Also pretty sure you don't understand why vacuum advance is used. Pretty sure you’re an a$$, I know exactly what I’m taking about. Do YOU know what manifold vacuum is? Do you know what carb port ABOVE and BELOW the throttle plate is? I know exactly what manifold vacuum is. I know exactly what ported vacuum is. Now tell us what manifold ported is, your terminology.

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: cudaman1969] #2918329 05/04/21 09:33 AM 05/04/21 09:33 AM
Joined: Nov 2004 Posts: 144 T Tony440 member
Tony440 member T Joined: Nov 2004 Posts: 144	Hello, I have a question related to manifold vs. ported vacuum for the vacuum advance. I know it's not directly related to this thread. But I have a 67 R/T with a 440 that has a Speed Pro cam that's 300/300 at the seat 230/230@.050, 109 LSA and .480 lift. With the vacuum advance hooked to the ported connection(factory) port on the carb the idle is somewhat choppy. I was advised to connect the vacuum advance to manifold vacuum, which I did and this really cleaned up the idle. I almost forgot to mention that I have a six pack setup on the car as well. Does anyone see a problem with using the manifold vacuum for the vacuum advance with this setup? Thanks everyone!

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: Tony440] #2918335 05/04/21 09:47 AM 05/04/21 09:47 AM
Joined: Aug 2006 Posts: 2,496 God's Country Maryland GODSCOUNTRY340 top fuel
GODSCOUNTRY340 top fuel Joined: Aug 2006 Posts: 2,496 God's Country Maryland	Pic I love the smell of Deer guts in the morning, it smells like... VICTORY!

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: Tony440] #2918340 05/04/21 09:57 AM 05/04/21 09:57 AM
Joined: Nov 2003 Posts: 10,228 Colleyville 3hundred I Live Here
3hundred I Live Here Joined: Nov 2003 Posts: 10,228 Colleyville	Originally Posted by Tony440 Hello, I have a question related to manifold vs. ported vacuum for the vacuum advance. I know it's not directly related to this thread. But I have a 67 R/T with a 440 that has a Speed Pro cam that's 300/300 at the seat 230/230@.050, 109 LSA and .480 lift. With the vacuum advance hooked to the ported connection(factory) port on the carb the idle is somewhat choppy. I was advised to connect the vacuum advance to manifold vacuum, which I did and this really cleaned up the idle. I almost forgot to mention that I have a six pack setup on the car as well. Does anyone see a problem with using the manifold vacuum for the vacuum advance with this setup? Thanks everyone! Not an expert, I think what's happened is you've added a bunch of initial timing through the vacuum advance and disturbed the operational RPM range aspects of the vacuum advance. I'd put it back to ported, to the center carb metering block and go back and add initial timing to see if the idle stays "cleaned up". 2¢ '68 Fury Convertible '69 300 Convertible '15 Durango 5.7 Hemi '16 300 S Hemi

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: 3hundred] #2918344 05/04/21 10:11 AM 05/04/21 10:11 AM
Joined: Nov 2004 Posts: 144 T Tony440 member
Tony440 member T Joined: Nov 2004 Posts: 144	Thanks for the reply. The initial timing is at 10 deg. before, without the vacuum advance hooked up.

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: GODSCOUNTRY340] #2918363 05/04/21 10:32 AM 05/04/21 10:32 AM
Joined: Jan 2003 Posts: 10,697 North Dakota 6PakBee I Live Here
6PakBee I Live Here Joined: Jan 2003 Posts: 10,697 North Dakota	Originally Posted by GODSCOUNTRY340 Pic Wow. Maybe I'm a cynic but if you have to tell someone the PCV port is not for fuel, they may be better off owning a Prius. "We live in a time when intelligent people are being silenced so that stupid people won't be offended".

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: Tony440] #2918385 05/04/21 11:10 AM 05/04/21 11:10 AM
Joined: Feb 2005 Posts: 528 SW CO HemiSportFury mopar
HemiSportFury mopar Joined: Feb 2005 Posts: 528 SW CO	Originally Posted by Tony440 Thanks for the reply. The initial timing is at 10 deg. before, without the vacuum advance hooked up. When you put in a bigger cam you generally need more initial timing to clean up the idle. You did that by switching from ported to manifold vacuum. Adding initial timing also does this but then you may have too much total advance and you may have to recurve the distributor to reduce mechanical advance. If it idles good with manifold advance give it a try. It may work but as you open the throttle manifold vacuum drops and you will loose timing so it may not run well. If you get spark knock then you'll have to get into the distributor at which point you should go back to ported advance and start from there. Good luck. '64 Sport Fury, 528 Hemi, FiTech EFI, 4-speed, 4.10 Dana 60 '57 Belvedere 2dr sedan, current project in process '19 Cherokee Trail Hawk Elite '03 Ram 2500 CTD HO, 6-speed 214,000 miles and still going strong

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: HemiSportFury] #2918395 05/04/21 11:54 AM 05/04/21 11:54 AM
Joined: Nov 2004 Posts: 144 T Tony440 member
Tony440 member T Joined: Nov 2004 Posts: 144	Thank you that sounds like good advice.

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: 6PakBee] #2918406 05/04/21 12:27 PM 05/04/21 12:27 PM
Joined: Aug 2006 Posts: 2,496 God's Country Maryland GODSCOUNTRY340 top fuel
GODSCOUNTRY340 top fuel Joined: Aug 2006 Posts: 2,496 God's Country Maryland	Originally Posted by 6PakBee Originally Posted by GODSCOUNTRY340 Pic Wow. Maybe I'm a cynic but if you have to tell someone the PCV port is not for fuel, they may be better off owning a Prius. Ha ha, You're absolutely right. But you can bet Edelbrock was getting complaints from some people that their carb was flooding due to them having the fuel line hooked to that port. Plus, they have to protect themselves from the lawyers that sue over everything. I love the smell of Deer guts in the morning, it smells like... VICTORY!

Re: Do pre 1967 Mopars have a ported vac advance port on carb [Re: GODSCOUNTRY340] #2918421 05/04/21 01:12 PM 05/04/21 01:12 PM
Joined: Feb 2014 Posts: 1,696 central il. S second 70 top fuel
second 70 top fuel S Joined: Feb 2014 Posts: 1,696 central il.	Ok I just had to go look at the 64 AFB on my 65 Corvette. It does not have ported vacuum. Yes I know it's not a mopar but what chevy does is use manifold vacuum to increase timing under idle and light loads as a way to run more advance for better cruising and better gas mileage plus allowing for more mechanical advance. My factory distributor has 22 degrees mechanical that comes in early and when you add vacuum under low loads you have at least 35 total advance and closer to 40 cruising. But when you accelerate fast you lose vacuum and therefore retard timing so the engine doesn't knock. Just the opposite of Mopar.

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