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
Fury Fan
master
|
master
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: 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
|
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: dmerc]
#500652
10/23/09 07:25 PM
10/23/09 07:25 PM
|
Joined: Jan 2005
Posts: 12,424 Kalispell Mt.
HotRodDave
I Live Here
|
I Live Here
Joined: Jan 2005
Posts: 12,424
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: 2,473 Answering the call of the wild
ThermoQuad
top fuel
|
top fuel
Joined: Aug 2003
Posts: 2,473
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: 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
|
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: 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
|
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.
|
|
|
|
|