Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: ragtop]
#2916602
04/29/21 04:10 PM
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: cudaman1969]
#2916852
04/30/21 08:51 AM
04/30/21 08:51 AM
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dragon slayer
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No mopar had manifold ported vacuum for distributor...wait for it.. What does this statement even mean?
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: dragon slayer]
#2916862
04/30/21 09:23 AM
04/30/21 09:23 AM
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No mopar had manifold ported vacuum for distributor...wait for it.. What does this statement even mean? I think he's waiting for a typical moparts argument to break out? I'm interested in the answer as well, I'm not old enough to remember when or if direct manifold vacuum was used. I_think_ported vaccuum started in the emissions era but don't really know.
'68 Fury Convertible '69 300 Convertible '15 Durango 5.7 Hemi '16 300 S Hemi
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: 3hundred]
#2916880
04/30/21 10:08 AM
04/30/21 10:08 AM
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TJP
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Ported vacuum comes from a small opening / passage that is slightly above the primary throttle blades at normal idle opening IE: 750 or so RPM with no radical camshafts that require more throttle opening at idle speeds. As the throttle blades begin opening during acceleration the air passing by the opening begins drawing air (vacuum if sealed of hooked up to a non leaking vacuum advance. This is known as the venturi effect. See pic below. the red indicates air flow, the blue vacuum. As the throttle blades are opened, more air passes by the port and the vacuum increases adding more advance. So there is no vacuum available at idle speeds . Manifold vacuum ion the other hand is highest when the throttle blades are closed ( depending on camshaft) as the pistons are trying to draw air/ fuel against a restricted opening (the throttle blades). However it drops rapidly on acceleration due to the throttle blades opening. As one reaches cruising speed and the blade opening in relaxed the vacuum then returns to a higher state. Which is better? I'm not going to open that debate. To my knowledge Chrysler used ported vacuum in most applications. That may have changed during the emission years. hope this helps
Last edited by TJP; 04/30/21 10:11 AM.
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: 3hundred]
#2916939
04/30/21 11:38 AM
04/30/21 11:38 AM
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No mopar had manifold ported vacuum for distributor...wait for it.. What does this statement even mean? I think he's waiting for a typical moparts argument to break out? I'm interested in the answer as well, I'm not old enough to remember when or if direct manifold vacuum was used. I_think_ported vaccuum started in the emissions era but don't really know. I started working in service stations in 1961, I remember a lot of the early GM cars had manifold vacuum advance back then, hence the disconnect the vacuum advance and plug the fitting instructions before setting the timing As far as I can remember now all Mopars engines I worked on had ported vacuum advance, all of them
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: dragon slayer]
#2917001
04/30/21 02:04 PM
04/30/21 02:04 PM
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The info Cab furnished jibed with what I'd gleaned over the years. It seemed the older guys, the chev centric guys, all asserted manifold vacuum was the "correct" way to hook up vacuum advance to the point they'd arbitrarily change it to manifold on whatever car they were working on even if it didn't come that way. By the time I started my mechanic years (1973) mid '60's cars coming into the shop was a bit of a rarity, let alone earlier ones. At that time cars 5~10 years old made up the bulk of junkyard denizens which made parts for my '68 readily available cheaply.
'68 Fury Convertible '69 300 Convertible '15 Durango 5.7 Hemi '16 300 S Hemi
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: Sniper]
#2917166
04/30/21 10:05 PM
04/30/21 10:05 PM
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Well my 51 Plymouth has ported vacuum stock Were they still using hard plumbed lines then or had they gone to rubber hoses by then?
'68 Fury Convertible '69 300 Convertible '15 Durango 5.7 Hemi '16 300 S Hemi
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: 3hundred]
#2917246
05/01/21 08:16 AM
05/01/21 08:16 AM
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Well my 51 Plymouth has ported vacuum stock Were they still using hard plumbed lines then or had they gone to rubber hoses by then? Hard line from carb to vacuum canister, as is the 52 Dodge 230 I bought to build and hot rod.
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: Sniper]
#2917344
05/01/21 01:02 PM
05/01/21 01:02 PM
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moparx
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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.
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: moparx]
#2917585
05/02/21 09:19 AM
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i'm not going to start a debate here. everything was ported up to around 74ish [ The OP specifically asked about pre 67. Why bring up the newer stuff?
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: Sniper]
#2917667
05/02/21 12:55 PM
05/02/21 12:55 PM
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because it was stated previously that there was never manifold vacuum used. your point could also be used about 30's and 40's engines, as well as the steel and rubber lines. i was just offering a little more to the story, sorry if i rubbed you the wrong way. please accept my apology.
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: dragon slayer]
#2917979
05/03/21 11:50 AM
05/03/21 11:50 AM
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cudaman1969
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No mopar had manifold ported vacuum for distributor...wait for it.. What does this statement even mean? Wait for all the know it alls (keyboard jockeys) to claim otherwise.
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: NANKET]
#2917982
05/03/21 11:55 AM
05/03/21 11:55 AM
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cudaman1969
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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
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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
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cudaman1969
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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
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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
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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.
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: Sniper]
#2918027
05/03/21 01:38 PM
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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$$, I know exactly what I’m taking about. Do YOU know what manifold vacuum is? Do you know what carb port ABOVE and BELOW the throttle plate is?
Last edited by cudaman1969; 05/03/21 01:39 PM.
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: cudaman1969]
#2918128
05/03/21 06:37 PM
05/03/21 06:37 PM
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Short answer is yes there is a ported vacuum connection on carbs before 67. I have a 62 383-2bbl, and a 62 413-4bbl both have it done in rubber hoses. 1960 413-4bbl has it with a hard steel line. Not for distributor advance Your not serious are you? So what is it for if not distributor? I don't know why you would trash a thread for kicks with mis-information, clearly you are wrong in your statement. But why? That 66 hemi of yours has ported for the distributor.
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Re: Do pre 1967 Mopars have a ported vac advance port on carb
[Re: cudaman1969]
#2918306
05/04/21 08:15 AM
05/04/21 08:15 AM
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Still ported vacuum not straight, all those connections were used so engine got to operating temp first. Look at the advance ‘can’ on a mopar distributor. They ALL pull the plate in the timing advance direction so IF it’s manifold ported it would be in wrong direction, give it gas it drops, let off it advances, backward! Chevy was like that, had one, 70-1/2 Z28
Pretty sure you don't know the difference between manifold vacuum and ported vacuum. Also pretty sure you don't understand why vacuum advance is used. Pretty sure you’re an a$$, 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.
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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
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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
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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
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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".
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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
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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
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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
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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!
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