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Re: 25 MPG with a 408 ??? Yup!! [Re: dmerc] #500642 10/23/09 07:27 AM 10/23/09 07:27 AM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	Quote: IS THERE A TUNNEL RAM INTAKE THAT BOLTS UP TO MAGNUM HEADS?? Sorry about the caps. yes....if you redrill them to LA pattern 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: 25 MPG with a 408 ??? Yup!! [Re: dmerc] #500643 10/23/09 08:13 AM 10/23/09 08:13 AM
Joined: Jan 2003 Posts: 9,982 Ansonia, CT C CJK440 master
CJK440 master C Joined: Jan 2003 Posts: 9,982 Ansonia, CT	Quote: Quote: I'm assuming this was mostly, if not all highway?? All highway except for a little drag race with a mustang on the freeway. (guess who won?) I'd be interested in how the car does around the town. Thats where the T-quad will really shine. Steady RPM on the highway, you probably wont see much mpg diff with any other carb if A/F ratio is the same. But from stop light to stop light, the tiny primaries will be better suited. How it will work with the tranny & rear ratios will be interesting. 2017 Contusion Blue Challenger T/A 392 M6 "BLKNBLU"

Re: 25 MPG with a 408 ??? Yup!! [Re: dmerc] #500644 10/23/09 02:19 PM 10/23/09 02:19 PM
Joined: Mar 2008 Posts: 5,746 Ontario, Canada Dodgem master
Dodgem master Joined: Mar 2008 Posts: 5,746 Ontario, Canada	curious as to why you did not run 34 with 11 vacuum added on to achive the same cruise advance but have a little more WOT for more performance???

Re: 25 MPG with a 408 ??? Yup!! [Re: Dodgem] #500645 10/23/09 02:45 PM 10/23/09 02:45 PM
Joined: Dec 2004 Posts: 1,061 New Mexico D dmerc OP super stock
dmerc OP super stock D Joined: Dec 2004 Posts: 1,061 New Mexico	Everything I have read says that the more efficient combustion chamber of the magnum heads needs less advance. This also helps lower pumping loss at cruise. When I take it to the track I'll play with the timing to see if i can squeeze a little more out of it.

Re: 25 MPG with a 408 ??? Yup!! [Re: dmerc] #500646 10/23/09 03:21 PM 10/23/09 03:21 PM
Joined: Dec 2006 Posts: 3,533 Indiana F Fury Fan master
Fury Fan master F Joined: Dec 2006 Posts: 3,533 Indiana	The more efficient the chamber and port design, the less time you need for combustion (meaning, less ign advance), the less negative torque that will be created, and the less heat that will be lost to the cooling system. All adds up to more fuel efficiency. Parts I seek: driver doorpanel, 65 Sport Fury, prefer black, needs to be 7-8 on 10 scale, might buy set 16" x 6" Dodge truck wheel(s), from early 70s?, takes 9" dogdish - need for a research job so cheaper is better. 69-73 C-body caliper brackets and/or splashields Send a PM.

Re: 25 MPG with a 408 ??? Yup!! [Re: Fury Fan] #500647 10/23/09 03:28 PM 10/23/09 03:28 PM
Joined: Sep 2004 Posts: 2,091 oberlin, Ohio Rapid340 top fuel
Rapid340 top fuel Joined: Sep 2004 Posts: 2,091 oberlin, Ohio	The less timing required, the more efficient the combustion system (heads, chamber, piston, ignition). 1971 Factory Appearing Duster 340 11.000 @ 122 mph

Re: 25 MPG with a 408 ??? Yup!! [Re: Rapid340] #500648 10/23/09 03:43 PM 10/23/09 03:43 PM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	my mild 318 (combo listed above) seems to like 32 or so degrees of total advance for best power and economy. I'm using a 17 degree vac advance can on the dizzy, for a total of 49 degrees of cruise advance. 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: 25 MPG with a 408 ??? Yup!! [Re: patrick] #500649 10/23/09 03:48 PM 10/23/09 03:48 PM
Joined: Dec 2004 Posts: 1,061 New Mexico D dmerc OP super stock
dmerc OP super stock D Joined: Dec 2004 Posts: 1,061 New Mexico	I wonder what will make more power? 87 octane with a little timing pulled out or 91 octane with a couple degrees more timing advance??

Re: 25 MPG with a 408 ??? Yup!! [Re: dmerc] #500650 10/23/09 04:49 PM 10/23/09 04:49 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	Quote: I wonder what will make more power? 87 octane with a little timing pulled out or 91 octane with a couple degrees more timing advance?? #2 live every 24 hour block of time like it's your last day on earth

Re: 25 MPG with a 408 ??? Yup!! [Re: RapidRobert] #500651 10/23/09 05:59 PM 10/23/09 05:59 PM
Joined: Sep 2003 Posts: 650 Kansas R racincuda mopar
racincuda mopar R Joined: Sep 2003 Posts: 650 Kansas

Re: 25 MPG with a 408 ??? Yup!! [Re: dmerc] #500652 10/23/09 07:25 PM 10/23/09 07:25 PM
Joined: Jan 2005 Posts: 12,419 Kalispell Mt. H HotRodDave I Live Here
HotRodDave I Live Here H Joined: Jan 2005 Posts: 12,419 Kalispell Mt.	Depends on if what the engine needs. Normally in my experiance the magnum heads work best 32-34 mechanical advance. When I had my 318 mpg motor it really ran better with a very short mechanical advance and a short vaccume advance. If I remember the sweet spot for mechanical was 18 initial and 32 total. The shortest vaccume advance can I found was 8.5 and it did the best, I think it would have really liked a couple less total degrees. Once I got it all tuned right it ran the same on 87 octane as 93 and neither one wanted more advance. I am now at 3000 ft elevation so that lowered my preasure a hair. I am not causing global warming, I am just trying to hold off a impending Ice Age!

Re: 25 MPG with a 408 ??? Yup!! [Re: dmerc] #500653 10/24/09 12:36 AM 10/24/09 12:36 AM
Joined: Aug 2003 Posts: 2,465 Answering the call of the wild T ThermoQuad top fuel
ThermoQuad top fuel T Joined: Aug 2003 Posts: 2,465 Answering the call of the wild	Great work I wonder if a six pak would do even better. I am glad to see someone put some thought into having a fast [but old] car & gas mileage just like new tupperware can... [Tupperware refers to a corvette-plastic container with an airtight lid...] Have you put synthetic fluid in the diff??? Anything synthetic for lubricants will help raise the mileage as well. I have a very strong 416 six pak in an E body with overdrive that got 16 mpg going to & from Carlisle 180 miles each way. Speed was 55-70 mph mostly on cruise control. I'd show the naysayers my log book for the car but that's classified info.

Re: 25 MPG with a 408 ??? Yup!! [Re: Mr.Yuck] #500654 10/25/09 07:49 AM 10/25/09 07:49 AM
Joined: Jan 2003 Posts: 5,788 Hamilton, Ontario Canada Magnum master
Magnum master Joined: Jan 2003 Posts: 5,788 Hamilton, Ontario Canada	Quote: putting a 2.261 gear in a muscle car that you spent all kinds of $$$ building a 408 storker is like neutering your prize race horse because you want him to live longer.... if you wanted MPG's you could have just rebuilt a 318 and used a 2bbl throttle body. I love the idea of cubes and tall gears. GM did it with the previous generation Camaros. 5.7L with a 0.50 overdrive. 25-30 mpg and 13 second quarters. Small engines can't be run down the highway with tall overdrives. Most 4 cyl cars are above 3000rpm on the highway. Plus a 318 and a 2 barrel would be gutless compared to Dmercs combo. Power and mileage, that's a goal worth chasing. Quote: curious as to why you did not run 34 with 11 vacuum added on to achive the same cruise advance but have a little more WOT for more performance??? Magnums engines will not take advance like the LA headed engines. I've run my best times in my 5.9 Magnum at 30 deg total. Great work Dmerc. Your 408 has surpassed my best MPG of 23. With some similarities. I'm also Magnum headed but with stock cubes, 360. Also overdriven but with 5 speed manual and 3.55's. In a truck plagued with poor aerodynamics but as you I also firmly believe in vacuum advance. I run 18 vacuum on top of my 30 mechanical for a total of 48. Keep us posted on your 1/4 mile results. I predict you will have no problems surpassing 14's. 69 Super Bee, 93 Mustang LX, 04 Allure Super

Re: 25 MPG with a 408 ??? Yup!! [Re: Magnum] #500655 10/25/09 01:11 PM 10/25/09 01:11 PM
Joined: Dec 2004 Posts: 1,061 New Mexico D dmerc OP super stock
dmerc OP super stock D Joined: Dec 2004 Posts: 1,061 New Mexico	Thanks Magnum. I did go to the track yesterday and it did not go well. Car would launch flood out die. did it twice. I think the choke pull off is the culprit. It also functions to slow the opening of the secondary air valve. I've taken the choke pull off... off. This only happens at the drags when I really hammer it quickly.(in front of hundreds of people!) I'll know next week. I'm going to try again!!!

Re: 25 MPG with a 408 ??? Yup!! [Re: dmerc] #500656 10/23/12 05:52 PM 10/23/12 05:52 PM
Joined: Jan 2003 Posts: 4,395 The Pale Blue Dot Skeptic master
Skeptic master Joined: Jan 2003 Posts: 4,395 The Pale Blue Dot	Shameless with hopes for some updates

Re: 25 MPG with a 408 ??? Yup!! [Re: Skeptic] #500657 10/24/12 09:00 AM 10/24/12 09:00 AM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	dmerc's last post was over a year ago...you might be waiting a while 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

Re: 25 MPG with a 408 ??? Yup!! [Re: RapidRobert] #500658 10/24/12 09:06 AM 10/24/12 09:06 AM
Joined: Jan 2003 Posts: 14,610 Not2farfromNashville, TN R Rug_Trucker I Live Here
Rug_Trucker I Live Here R Joined: Jan 2003 Posts: 14,610 Not2farfromNashville, TN	"The only thing to do for triumph of evil is for good men to do nothing" "NUNQUAM NON PARATUS!"

Re: 25 MPG with a 408 ??? Yup!! [Re: dmerc] #500659 10/24/12 10:17 AM 10/24/12 10:17 AM
Joined: Sep 2006 Posts: 277 Palmyra, NY 6 63stabamatic enthusiast
63stabamatic enthusiast 6 Joined: Sep 2006 Posts: 277 Palmyra, NY	Sounds like a great combo! Looks like you're really on top of this project, but I have to ask. Is your odometer/speedometer calibrated?

Re: 25 MPG with a 408 ??? Yup!! [Re: 63stabamatic] #500660 10/24/12 01:51 PM 10/24/12 01:51 PM
Joined: Jan 2003 Posts: 4,395 The Pale Blue Dot Skeptic master
Skeptic master Joined: Jan 2003 Posts: 4,395 The Pale Blue Dot	Quote: dmerc's last post was over a year ago...you might be waiting a while Oh well interesting thread anyways. Last edited by Skeptic; 10/24/12 01:52 PM.

Re: 25 MPG with a 408 ??? Yup!! [Re: dmerc] #500661 10/24/12 02:07 PM 10/24/12 02:07 PM
Joined: Feb 2010 Posts: 18,493 Granite Bay CA Kern Dog Striving for excellence
Kern Dog Striving for excellence Joined: Feb 2010 Posts: 18,493 Granite Bay CA	Way to go, Dmerc. These great cars do NOT have to be "single purpose" machines. Efficiency crosses many lines and a clean running engine can be fast and fuel efficient. Late model cars are compromises of the big 3 factors: Emissions, economy and performance. YOUR efforts are in line with the OEMs, and it should be congratulated. Nice work. My car will never see 25 mpg even driving downhill with 90 series tires and the trans in neutral. I do plan on improving the combination to maximize mpgs, but there are some points to which I will not concede. I will not modify the exterior, change the tires or switch to a smaller engine. The T-Quad carb could be the single most effective modification to improve mpgs. Your efforts are paying off, and posting them here will certainly help others reach their goals. Thank you. Last edited by Frankenduster; 10/24/12 02:08 PM.

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