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Question on 6 Pack Vaccuum requirement #1484979 08/15/13 12:17 PM 08/15/13 12:17 PM
Joined: May 2005 Posts: 476 Mount Airy, Maryland S scrag OP mopar
scrag OP mopar S Joined: May 2005 Posts: 476 Mount Airy, Maryland	I currently have 7" at idle (800 RPM) I have read a lot about 6 pack tuning, I don't think the car is making the power it should that maybe the carbs are not opening when they should (light yellow springs on the outboards) I have a Hydraulic Roller cam and roller upper end. Manual brakes....so the only thing requiring vacuum is the carbs and the PVC. This is a new engine (500 miles on it) manual transmission.....is 7" enough to do the job? I really wanted to stay with the 6 pack....but....

Re: Question on 6 Pack Vaccuum requirement [Re: scrag] #1484980 08/15/13 12:45 PM 08/15/13 12:45 PM
Joined: Aug 2011 Posts: 1,083 SE PA Yellow Fever super stock
Yellow Fever super stock Joined: Aug 2011 Posts: 1,083 SE PA	What motor? 440 or 340 or???? What is your timing at? What size roller cam? Give it as much base timing as it will take and that should help your vacuum some. http://www.mopar1.us/6barreltips.html

Re: Question on 6 Pack Vaccuum requirement [Re: Yellow Fever] #1484981 08/15/13 01:07 PM 08/15/13 01:07 PM
Joined: May 2003 Posts: 6,640 Downtown Roebuck Ont Twostick Still wishing...
Twostick Still wishing... Joined: May 2003 Posts: 6,640 Downtown Roebuck Ont	Manifold vacuum has nothing to do with opening the outboard carbs. Kevin

Re: Question on 6 Pack Vaccuum requirement [Re: Twostick] #1484982 08/15/13 01:29 PM 08/15/13 01:29 PM
Joined: Jun 2008 Posts: 3,916 usa L lewtot184 master
lewtot184 master L Joined: Jun 2008 Posts: 3,916 usa	Quote: Manifold vacuum has nothing to do with opening the outboard carbs. Kevin x2, it's air velocity thru the passenger side center carb venturi. look for a fuel delivery problem.

Re: Question on 6 Pack Vaccuum requirement [Re: lewtot184] #1484983 08/15/13 09:41 PM 08/15/13 09:41 PM
Joined: May 2005 Posts: 476 Mount Airy, Maryland S scrag OP mopar
scrag OP mopar S Joined: May 2005 Posts: 476 Mount Airy, Maryland	My post was stupid - apologies. Engine is a 500 CID stroker (based on a 440) cam specs are: intake exhaust Duration .050 252 256 Separation 109 Gross Valve lift .573 .567 Timing was set at 38 degrees total. Jets are 84 in the outboards and 66 CL. I have the promax center mixture block, outboard jet plates and the rear carb has the promax base. TTI headers 2 into 3.5. It feels pretty smooth (asked a lot of questions here - thanks for the knowledge base) and was thinking of doing a Dyno tune to get it dialed (pricey) - this is a street car and I could be second guessing myself too..I will recheck the center venture (passenger side) I was thought it was a bit on the rich side - a tad - but I was told that 6 packs tend to do this - again many thanks.

Re: Question on 6 Pack Vaccuum requirement [Re: scrag] #1484984 08/16/13 12:38 AM 08/16/13 12:38 AM
Joined: Oct 2003 Posts: 2,537 PORT ALBERNI , BC., CANADA superwrench master
superwrench master Joined: Oct 2003 Posts: 2,537 PORT ALBERNI , BC., CANADA	With any of the yellow springs, those end carbs should come on VERY quick. I went one step up to the purples to take a bit of hit out of the car.I have a Comp XTQ296 cam.....264/270 @ .050 and about the same vacuum reading as you. Stomp the loud peddle.......1.45 60' and HOLD ON. Make sure those end carbs cycle freely... and another thing that might sound stupid......make sure the base gasket is on the right way otherwise the end carbs will NOT open. I've ran into that twice on a couple of customers cars. As said, engine vacuum has nothing to do with the end carbs opening.

Re: Question on 6 Pack Vaccuum requirement [Re: superwrench] #1484985 08/16/13 12:58 AM 08/16/13 12:58 AM
Joined: Jun 2009 Posts: 233 vashon island washington hunterstroble enthusiast
hunterstroble enthusiast Joined: Jun 2009 Posts: 233 vashon island washington	I had a new engine I wass dissapointed with until one day I noticed my throttle cable was only opening up the throttle 75%. Dumb question, is your throttle getting max pull? 1969 Dodge dart 500 stroker 1973 Dodge Challenger 440

Re: Question on 6 Pack Vaccuum requirement [Re: hunterstroble] #1484986 08/16/13 09:19 AM 08/16/13 09:19 AM
Joined: Oct 2005 Posts: 797 arizona, usa L lokalik super stock
lokalik super stock L Joined: Oct 2005 Posts: 797 arizona, usa	are the diaphrams new? about every other year i have to replace mine, i can tell when its time because the outboards open late ( not at the rpm they should) and the car pulls slow, replace the diaphrams and it really makes a difference.

Re: Question on 6 Pack Vaccuum requirement [Re: superwrench] #1484987 08/16/13 09:22 AM 08/16/13 09:22 AM
Joined: Feb 2003 Posts: 12,675 Columbia, CT M moper I Live Here
moper I Live Here M Joined: Feb 2003 Posts: 12,675 Columbia, CT	Quote: Make sure those end carbs cycle freely... and another thing that might sound stupid......make sure the base gasket is on the right way otherwise the end carbs will NOT open. I've ran into that twice on a couple of customers cars. As said, engine vacuum has nothing to do with the end carbs opening. x2 - the gaskets can also hold the secondaries open... DAMHIK Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.

Re: Question on 6 Pack Vaccuum requirement [Re: superwrench] #1484988 08/16/13 09:58 AM 08/16/13 09:58 AM
Joined: Jan 2003 Posts: 24,562 Brookeville, Md Mr.Yuck Not enough dumb comments...yet
Mr.Yuck Not enough dumb comments...yet Joined: Jan 2003 Posts: 24,562 Brookeville, Md	why do you have the idle so low? I'd think you'd want it a tad higher. I'm running a solid roller, (588) I pull about 8-9 at idle (900-1000rpm) I'm running the stock MP 6-pack, I'm using 70main jets (probably a tad rich) 35 squirters, and purple springs. I'd probably go back to square one, set your timing in full at 36* early 2200rpm, turn you mixture screws all the way in them out a turn and go from there, tweak for best vacuum. You should also make sure your outboards are opening 100% Your build should fly. not sure how the billet blocks work, but it should run fine w/ or w/o them. I adjusted my primary w/o the outboards hooked up. Good luck [IMG]http://i66.tinypic.com/pui5j.jpg[/IMG] Coming soon!!!!

Re: Question on 6 Pack Vaccuum requirement [Re: Mr.Yuck] #1484989 08/16/13 10:40 AM 08/16/13 10:40 AM
Joined: May 2005 Posts: 476 Mount Airy, Maryland S scrag OP mopar
scrag OP mopar S Joined: May 2005 Posts: 476 Mount Airy, Maryland	I checked the butterflies and gasket - (found that problem early on and as I tighten the carbs down I work the throttle open and close to make sure it is not interfering (thought I had a throttle stick and that was the culprit after junked base plate. I will check actual cable travel - that would be almost funny but I have not done that yet....I will replace the diaphrams too - maybe go to a stiffer spring.

Re: Question on 6 Pack Vaccuum requirement [Re: scrag] #1484990 08/16/13 11:45 AM 08/16/13 11:45 AM
Joined: Oct 2003 Posts: 2,537 PORT ALBERNI , BC., CANADA superwrench master
superwrench master Joined: Oct 2003 Posts: 2,537 PORT ALBERNI , BC., CANADA	Even at 1/2 throttle, when the load/venturi signal is right, those end carbs will still give a kick in the Azz with the light springs.If you're not having the feeling that all h&ll is breaking loose, then something is NOT right. Vacuum hoses to carbs are on right???

Re: Question on 6 Pack Vaccuum requirement [Re: scrag] #1484991 08/16/13 11:48 AM 08/16/13 11:48 AM
Joined: Aug 2005 Posts: 11,543 chicagoland,usa B buildanother I Live Here
buildanother I Live Here B Joined: Aug 2005 Posts: 11,543 chicagoland,usa	I bought new carbs in around 1998 that had the vacuum passage completey plugged solid between vac pods and venturis of the end barbs. There is a restricted airway there and these had NO air getting through and I also found the out of box performance poor on my 500 cube duster. Opened the airway and the car then ran like it should have. Just saying.

Re: Question on 6 Pack Vaccuum requirement [Re: buildanother] #1484992 08/16/13 11:51 AM 08/16/13 11:51 AM
Joined: Jun 2008 Posts: 3,916 usa L lewtot184 master
lewtot184 master L Joined: Jun 2008 Posts: 3,916 usa	check fuel supply, pressure and volume.

Re: Question on 6 Pack Vaccuum requirement [Re: lewtot184] #1484993 08/16/13 03:02 PM 08/16/13 03:02 PM
Joined: May 2005 Posts: 476 Mount Airy, Maryland S scrag OP mopar
scrag OP mopar S Joined: May 2005 Posts: 476 Mount Airy, Maryland	Well I took a the vacuum lines off and tested each carb - rear carb works like a champ front carb hisses....diaphragm is toast and it is my fault as I over tightened the cover when I was swapped the springs out....and of course no one in MD has a 135-6 diaphragm. I have one place left to try...thanks for the help. I am also going to spring is lt silver and not yellow btw... 7816612-IMG_0807a.jpg (107 downloads) Last edited by scrag; 08/16/13 03:03 PM.

Re: Question on 6 Pack Vaccuum requirement [Re: scrag] #1484994 08/16/13 04:42 PM 08/16/13 04:42 PM
Joined: May 2003 Posts: 6,640 Downtown Roebuck Ont Twostick Still wishing...
Twostick Still wishing... Joined: May 2003 Posts: 6,640 Downtown Roebuck Ont	That'll do it. Kevin

Re: Question on 6 Pack Vaccuum requirement [Re: scrag] #1484995 08/16/13 04:46 PM 08/16/13 04:46 PM
Joined: Oct 2003 Posts: 2,537 PORT ALBERNI , BC., CANADA superwrench master
superwrench master Joined: Oct 2003 Posts: 2,537 PORT ALBERNI , BC., CANADA	Promax will have them. I don't know whether Mopar Performance still has them or not....I bought 3 of them about 2 years ago. Yep....those screws don't have to be overtight...the diaphragm will just squish out if they are snugged up too much. DAMHIK. And yes....put yellow springs in there. The plain ones are a tad stiff.

Re: Question on 6 Pack Vaccuum requirement [Re: scrag] #1484996 08/16/13 05:20 PM 08/16/13 05:20 PM
Joined: Jan 2003 Posts: 24,562 Brookeville, Md Mr.Yuck Not enough dumb comments...yet
Mr.Yuck Not enough dumb comments...yet Joined: Jan 2003 Posts: 24,562 Brookeville, Md	Quote: Well I took a the vacuum lines off and tested each carb - rear carb works like a champ front carb hisses....diaphragm is toast and it is my fault as I over tightened the cover when I was swapped the springs out....and of course no one in MD has a 135-6 diaphragm. I have one place left to try...thanks for the help. I am also going to spring is lt silver and not yellow btw... I have one or 2 on my bench... except I'm in SC until Sunday. If you can't find one by then PM me. Advanced Auto has a complete re-build kit however it's like $35 [IMG]http://i66.tinypic.com/pui5j.jpg[/IMG] Coming soon!!!!

Re: Question on 6 Pack Vaccuum requirement [Re: scrag] #1484997 08/16/13 07:50 PM 08/16/13 07:50 PM
Joined: Jan 2003 Posts: 9,436 Blair County,PA 62maxwgn master
62maxwgn master Joined: Jan 2003 Posts: 9,436 Blair County,PA	Have a few !! Also,put a little grease on the screws,if not the screw can catch and tear the rubber around the hole if the opening is not centered over the hole. 7816868-Picture1027.jpg (132 downloads)

Re: Question on 6 Pack Vaccuum requirement [Re: 62maxwgn] #1484998 08/16/13 08:15 PM 08/16/13 08:15 PM
Joined: Oct 2003 Posts: 2,537 PORT ALBERNI , BC., CANADA superwrench master
superwrench master Joined: Oct 2003 Posts: 2,537 PORT ALBERNI , BC., CANADA	Quote: Have a few !! Also,put a little grease on the screws,if not the screw can catch and tear the rubber around the hole if the opening is not centered over the hole.o Like he says....

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