|
Re: 25 MPG with a 408 ??? Yup!!
[Re: hooziewhatsit]
#500586
10/18/09 10:14 PM
10/18/09 10:14 PM
|
Joined: Dec 2004
Posts: 1,061
New Mexico
dmerc
OP
super stock
|
OP
super stock
Joined: Dec 2004
Posts: 1,061
New Mexico
|
Here's the recipe:
Magnum heads with tight quench .030. Bowls opened up. Stock valve job.
Wiesco dished pistons
Mopar Performance M1 Dual plane intake
Roller cam Compcams #20-000-9 506 lift 216 intake 224 exhaust duration.
Mopar orange box. 340 HP manifolds with a TTI 2 1/2 inch exhaust system.
Distributor that I recurved for timing all in at 2000 RPM.
This is a big one: Thermoquad 850 carb. Best carb I've tried and I've tried them all.
700R4 Chevy trany with converter lockup. But any overdrive trans would work.
3.23 8 3/4 rear end
Aluminum radiator with electric fans. Fans don't operate at anything over 40 MPH so you gain at least 1 MPG with that mod.
Last edited by dmerc; 10/18/09 10:34 PM.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: dmerc]
#500588
10/18/09 10:25 PM
10/18/09 10:25 PM
|
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
What is your (measured) CR and what gas?
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: dmerc]
#500592
10/18/09 10:38 PM
10/18/09 10:38 PM
|
Joined: Aug 2005
Posts: 6,003
Salem
Grizzly
Moparts Proctologist
|
Moparts Proctologist
Joined: Aug 2005
Posts: 6,003
Salem
|
You did it!  I'm going to be optimistic and say you will hit somewhere between 12.8 and 13.2 seconds in the quarter. Now let's see....  Skinny tires, lower it, and 3.08's; sounds like 27mpg to me? 
Mo' Farts
Moderated by "tbagger".
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Mr.Yuck]
#500597
10/21/09 08:11 PM
10/21/09 08:11 PM
|
Joined: Mar 2005
Posts: 1,545
Seattle, WA
375inStroke
Special needs person
|
Special needs person
Joined: Mar 2005
Posts: 1,545
Seattle, WA
|
Quote:
why build a 408 to run 13.5? Who care about mpg...make it run right and you might be able to pull a 13.0.
13.0 MPG? 
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: 375inStroke]
#500598
10/21/09 08:51 PM
10/21/09 08:51 PM
|
Joined: Feb 2009
Posts: 982
W. Sacto CA. USA
phantomx
super stock
|
super stock
Joined: Feb 2009
Posts: 982
W. Sacto CA. USA
|
I'd be interested in the MPH when you run it. Sounds like a good street combo.
Travis..
70 GTX project, orig 440-4, 4 spd, track pack, FC7, stripper/street racer special.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: phantomx]
#500599
10/21/09 09:01 PM
10/21/09 09:01 PM
|
Joined: Jan 2003
Posts: 9,982
Ansonia, CT
CJK440
master
|
master
Joined: Jan 2003
Posts: 9,982
Ansonia, CT
|
I'm assuming this was mostly, if not all highway??
2017 Contusion Blue Challenger T/A 392 M6 "BLKNBLU"
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: phantomx]
#500600
10/21/09 09:07 PM
10/21/09 09:07 PM
|
Joined: Dec 2004
Posts: 1,061
New Mexico
dmerc
OP
super stock
|
OP
super stock
Joined: Dec 2004
Posts: 1,061
New Mexico
|
Quote:
I'd be interested in the MPH when you run it. Sounds like a good street combo.
Travis..
I'll be taking the Duster to the drags to see what it will do on Sat. I'll report back. Hope I don't blow it up!!
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: CJK440]
#500601
10/21/09 09:17 PM
10/21/09 09:17 PM
|
Joined: Dec 2004
Posts: 1,061
New Mexico
dmerc
OP
super stock
|
OP
super stock
Joined: Dec 2004
Posts: 1,061
New Mexico
|
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?)
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: cogen80]
#500603
10/22/09 12:48 AM
10/22/09 12:48 AM
|
Joined: Feb 2009
Posts: 982
W. Sacto CA. USA
phantomx
super stock
|
super stock
Joined: Feb 2009
Posts: 982
W. Sacto CA. USA
|
I had a 360, O/D 833, and 3.23 gears in my 67 Barracuda. That car FLEW on the freeway, 100 mph @ 3K rpm Spent most of my commute @ 2200 in the fast lane. Travis..
70 GTX project, orig 440-4, 4 spd, track pack, FC7, stripper/street racer special.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: cogen80]
#500604
10/22/09 07:59 AM
10/22/09 07:59 AM
|
Joined: Dec 2004
Posts: 1,061
New Mexico
dmerc
OP
super stock
|
OP
super stock
Joined: Dec 2004
Posts: 1,061
New Mexico
|
Quote:
damn whats that like a 2.30 gear ratio in OD with those gears and tires?
2.261 to be exact! Just rumbles along at 70 MPH.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: dmerc]
#500605
10/22/09 08:26 AM
10/22/09 08:26 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
|
Quote:
Here's the recipe:
Magnum heads with tight quench .030. Bowls opened up. Stock valve job.
Wiesco dished pistons
Mopar Performance M1 Dual plane intake
Roller cam Compcams #20-000-9 506 lift 216 intake 224 exhaust duration.
Mopar orange box. 340 HP manifolds with a TTI 2 1/2 inch exhaust system.
Distributor that I recurved for timing all in at 2000 RPM.
This is a big one: Thermoquad 850 carb. Best carb I've tried and I've tried them all.
700R4 Chevy trany with converter lockup. But any overdrive trans would work.
3.23 8 3/4 rear end
Aluminum radiator with electric fans. Fans don't operate at anything over 40 MPH so you gain at least 1 MPG with that mod.
one question: are you running an adapter for the t-quad on the M1 dual plane, or is it capable of bolting up a spread bore?
some thoughts on the combo, it sounds like a real fun street combo, you could probably get a fair amount more power (~20-25HP & TQ) without sacraficing fuel economy (maybe even help a bit) going to headers.
you're leaving power on the table with the stock valve job in the magnum heads. it's undersized from the factory, and there's gains to be had to opening it and the pushrod pinch up (probably ~40-50HP)....would be interesting to see the power/economy difference with some lightly massaged EQ 318 (hughes "iron ram") heads or RHS heads
from what I've heard the M1 leaves something to be desired as far as performance, that it's essentially no better flow wise than a stock piece. would be interesting to try an LD340 modified to fit the t-quad....that might net you another 15-20HP....
I've thought that comp cam (XR265HR) would make a nice street cam for a small block....it must idle pretty much near stock with 408 cubes under it.
best I've managed so far with my 318 is 18mpg...combo is stock short block, home massaged magnum heads, reground cam by bullet cams, 259/259 adv, 208/208@.050, .316" lobe lift, .506" @ valve, headers, 3" single exhaust, RPM air gap, eddie 1406.
tranny is an A500, rear gears are 3.55, tires are 27" tall...car is a 5th ave, 3950lbs w/o me. I think my carb is what's holding my mileage back now...I haven't done an all highway/freeway trip, I'm guessing it'd hit 20.
Last edited by patrick; 10/22/09 08:30 AM.
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]
#500606
10/22/09 08:51 AM
10/22/09 08:51 AM
|
Joined: Dec 2004
Posts: 1,061
New Mexico
dmerc
OP
super stock
|
OP
super stock
Joined: Dec 2004
Posts: 1,061
New Mexico
|
Quote:
Quote:
Here's the recipe:
Magnum heads with tight quench .030. Bowls opened up. Stock valve job.
Wiesco dished pistons
Mopar Performance M1 Dual plane intake
Roller cam Compcams #20-000-9 506 lift 216 intake 224 exhaust duration.
Mopar orange box. 340 HP manifolds with a TTI 2 1/2 inch exhaust system.
Distributor that I recurved for timing all in at 2000 RPM.
This is a big one: Thermoquad 850 carb. Best carb I've tried and I've tried them all.
700R4 Chevy trany with converter lockup. But any overdrive trans would work.
3.23 8 3/4 rear end
Aluminum radiator with electric fans. Fans don't operate at anything over 40 MPH so you gain at least 1 MPG with that mod.
one question: are you running an adapter for the t-quad on the M1 dual plane, or is it capable of bolting up a spread bore?
some thoughts on the combo, it sounds like a real fun street combo, you could probably get a fair amount more power (~20-25HP & TQ) without sacraficing fuel economy (maybe even help a bit) going to headers.
you're leaving power on the table with the stock valve job in the magnum heads. it's undersized from the factory, and there's gains to be had to opening it and the pushrod pinch up (probably ~40-50HP)....would be interesting to see the power/economy difference with some lightly massaged EQ 318 (hughes "iron ram") heads or RHS heads
from what I've heard the M1 leaves something to be desired as far as performance, that it's essentially no better flow wise than a stock piece. would be interesting to try an LD340 modified to fit the t-quad....that might net you another 15-20HP....
I've thought that comp cam (XR265HR) would make a nice street cam for a small block....it must idle pretty much near stock with 408 cubes under it.
best I've managed so far with my 318 is 18mpg...combo is stock short block, home massaged magnum heads, reground cam by bullet cams, 259/259 adv, 208/208@.050, .316" lobe lift, .506" @ valve, headers, 3" single exhaust, RPM air gap, eddie 1406.
tranny is an A500, rear gears are 3.55, tires are 27" tall...car is a 5th ave, 3950lbs w/o me. I think my carb is what's holding my mileage back now...I haven't done an all highway/freeway trip, I'm guessing it'd hit 20.
Hey Patrick, I do have an adapter on my M1. It's a square bore manifold. I know I left at least 50HP on the table but I wanted a stock idle with some hit to it. I debated having a three angle valve job but just ended up having the bowls hogged out and doing a nice bowl blend. This experiment was to try to make the engine as efficient as possible with high performance as a secondary goal. I know I'll want more power in the future. I have a new crosswinds manifold I might try out. If you are not running a thermoquad I can almost guaranty you'll get 2 to 3 MPG better gas mileage with one. They are just outstanding at atomizing the fuel at small throttle openings.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: dmerc]
#500607
10/22/09 09:02 AM
10/22/09 09:02 AM
|
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
|
Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
|
Quote:
Quote:
damn whats that like a 2.30 gear ratio in OD with those gears and tires?
2.261 to be exact! Just rumbles along at 70 MPH.
putting a 2.261 gear in a muscle car that you spent all kinds of $$$ building a 408 storker is like neutering your prize race horse because you want him to live longer.... if you wanted MPG's you could have just rebuilt a 318 and used a 2bbl throttle body. 
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Mr.Yuck]
#500608
10/22/09 09:10 AM
10/22/09 09:10 AM
|
Joined: Oct 2009
Posts: 164
Indiana, United Staes, Vevay
LikarockCrusher
member
|
member
Joined: Oct 2009
Posts: 164
Indiana, United Staes, Vevay
|
Quote:
Quote:
Quote:
damn whats that like a 2.30 gear ratio in OD with those gears and tires?
2.261 to be exact! Just rumbles along at 70 MPH.
putting a 2.261 gear in a muscle car that you spent all kinds of $$$ 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 AGREE! My question is what is the Volume Eff.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: LikarockCrusher]
#500609
10/22/09 09:25 AM
10/22/09 09:25 AM
|
Joined: Jul 2005
Posts: 3,072
Farmland, IN
Ludington1
master
|
master
Joined: Jul 2005
Posts: 3,072
Farmland, IN
|
Quote:
Quote:
Quote:
Quote:
damn whats that like a 2.30 gear ratio in OD with those gears and tires?
2.261 to be exact! Just rumbles along at 70 MPH.
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 AGREE! My question is what is the Volume Eff.
I think that's just his ratio in OD
Nice build and stats, thanks for sharing!
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: dmerc]
#500610
10/22/09 10:48 AM
10/22/09 10:48 AM
|
Joined: Nov 2007
Posts: 5,337
the house on the left.
cogen80
master
|
master
Joined: Nov 2007
Posts: 5,337
the house on the left.
|
Quote:
Quote:
damn whats that like a 2.30 gear ratio in OD with those gears and tires?
2.261 to be exact! Just rumbles along at 70 MPH.
i guess the 408 with a 3.23 is still pretty peppy around town right?
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: cogen80]
#500611
10/22/09 11:37 AM
10/22/09 11:37 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
|
probably, especially considering the 700R4 has a 3.09:1 first gear, so overall first gear is effectively like a 727 with a 4.10.
my setup, with an A500 (2.74 first gear, .69 OD) and 3.55's is like a 727 with 3.91's in first, and a 2.45 rear in OD...
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]
#500612
10/22/09 11:42 AM
10/22/09 11:42 AM
|
Joined: Nov 2007
Posts: 5,337
the house on the left.
cogen80
master
|
master
Joined: Nov 2007
Posts: 5,337
the house on the left.
|
Quote:
probably, especially considering the 700R4 has a 3.09:1 first gear, so overall first gear is effectively like a 727 with a 4.10.
my setup, with an A500 (2.74 first gear, .69 OD) and 3.55's is like a 727 with 3.91's in first, and a 2.45 rear in OD...
good point. i forgot about that. at first it sounds like a waste until you really look at the trans and gears.. not bad.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: dmerc]
#500613
10/22/09 12:02 PM
10/22/09 12:02 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
|
Quote:
Hey Patrick, I do have an adapter on my M1. It's a square bore manifold. I know I left at least 50HP on the table but I wanted a stock idle with some hit to it. I debated having a three angle valve job but just ended up having the bowls hogged out and doing a nice bowl blend. This experiment was to try to make the engine as efficient as possible with high performance as a secondary goal. I know I'll want more power in the future. I have a new crosswinds manifold I might try out. If you are not running a thermoquad I can almost guaranty you'll get 2 to 3 MPG better gas mileage with one. They are just outstanding at atomizing the fuel at small throttle openings.
I followed this article by dulcich porting my mag heads....looking at his results, the bowl doesn't look like much of a restriction, the undersized valve job and especially the pushrod pinch seemed to me to make the biggest difference.
one thing with the air gap/crosswind, it's taller than stock (I presume the M1 is a low rise (stock height) intake if you can fit a stock air cleaner with an adapter). right now I have about 1/2" between my stock air cleaner and hood in my M body with an RPM air gap. you will probably be better served with an LD340, as they can be modded to use a spread bore carb without an adapter, and are about the same height as an Air gap (it's essentially the precursor to the eddie RPM manifold).
to all the people questioning "why?" well, some of us like to drive our cars a lot. I pulled my old 360 combo and sold it, it worked very well for what it was, pushing my porky M body to keep up with a 5.7L LX car, but with my existing OD tranny and rear gear could manage a best of 15 MPG in my daily commute (about 60/40 hwy/cty). I built up my roller cammed 318, and on the butt dyno it feels as strong as my old 360 combo, while having 4" more vaccuum at idle (it has a very stockish idle now, which I like), and increasing my mileage 20% (up to 18 in my commute).
power and economy are not mutually exclusive. look at the Z06 vette-- 505HP out of a [Email]218@050[/Email] hydraulic cam, and over 20mpg highway, or my friend's SRT8 300C--high 12's out of a 4200 lb car, that manages ~22mpg highway.
what's available for a t-quad as far as choke options? are they all the well style, or can you find some with an electric choke? I've thought about switching my airgap/600 eddie to an LD340/tquad or qjet combo, figuring I wouldn't lose performance, but perhaps gain economy. of course, I've got about 80% of the parts to convert my car to MPI, just don't have the time to sort it all out.
I think you could help both power and economy with headers. another thought I've had for economy and power was high compression, short timing cam with wide LSA, high flowing heads, and use water injection to suppress detonation.
something like ported RHS magnum heads, flat top pistons, tight quench (would be about 11.5:1), a single pattern cam with maybe 2-4 degrees more intake .050 duration than yours, but ~.540 lift on a 112 or 114 LSA installed at 108,
headers, LD340, and t-quad with water injection....I'd expect it to be in the 470-500 HP range, with a peak just north of 5000 RPM, mondo TORK! mild idle, and something that could squeak out over 20 mpg on a highway trip.
Last edited by patrick; 10/22/09 12:02 PM.
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: Mr.Yuck]
#500614
10/22/09 12:03 PM
10/22/09 12:03 PM
|
Joined: Dec 2006
Posts: 3,533
Indiana
Fury Fan
master
|
master
Joined: Dec 2006
Posts: 3,533
Indiana
|
Quote:
why build a 408 to run 13.5? Who care about mpg...make it run right and you might be able to pull a 13.0.
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.
Dang, Swingin', why you gotta rain on his parade?  It's his daily driver. The guy built a combo with a good sweetspot he should be congratulated, not ridiculed.
Go put 4.88s in everything you own and poke your fuel tank with an icepick so you can use as much gas as you see fit.
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: cogen80]
#500615
10/22/09 12:03 PM
10/22/09 12:03 PM
|
Joined: Dec 2004
Posts: 1,061
New Mexico
dmerc
OP
super stock
|
OP
super stock
Joined: Dec 2004
Posts: 1,061
New Mexico
|
Quote:
Quote:
Quote:
damn whats that like a 2.30 gear ratio in OD with those gears and tires?
2.261 to be exact! Just rumbles along at 70 MPH.
i guess the 408 with a 3.23 is still pretty peppy around town right?
Just to put it in perspective I had to put the 275 tires on the rear to keep wheelspin down. First gear was almost useless. Now I can leave the line under control and only have wheel spin part way through 2nd. I don't know why I got the negative comments from some people. Don't they know a transmission has more than one gear? 
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Fury Fan]
#500616
10/22/09 12:14 PM
10/22/09 12:14 PM
|
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
|
Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
|
Quote:
Quote:
why build a 408 to run 13.5? Who care about mpg...make it run right and you might be able to pull a 13.0.
Quote:
putting a 2.261 gear in a muscle car that you spent all kinds of $$$ building a 408 storker is like neutering your prize race horse because you want him to live longer.... if you wanted MPG's you could have just rebuilt a 318 and used a 2bbl throttle body.
Dang, Swingin', why you gotta rain on his parade? It's his daily driver. The guy built a combo with a good sweetspot he should be congratulated, not ridiculed.
Go put 4.88s in everything you own and poke your fuel tank with an icepick so you can use as much gas as you see fit.
hahaha no, not to rain but why build a 408 if you want mpg's? go buy a car that gets good gas milage.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Mr.Yuck]
#500617
10/22/09 12:36 PM
10/22/09 12:36 PM
|
Joined: Jan 2003
Posts: 6,816
Alton, IL
Dakota_Don
master
|
master
Joined: Jan 2003
Posts: 6,816
Alton, IL
|
Quote:
Quote:
Quote:
why build a 408 to run 13.5? Who care about mpg...make it run right and you might be able to pull a 13.0.
Quote:
putting a 2.261 gear in a muscle car that you spent all kinds of $$$ 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.
Dang, Swingin', why you gotta rain on his parade? It's his daily driver. The guy built a combo with a good sweetspot he should be congratulated, not ridiculed.
Go put 4.88s in everything you own and poke your fuel tank with an icepick so you can use as much gas as you see fit.
hahaha no, not to rain but why build a 408 if you want mpg's? go buy a car that gets good gas milage.
a 408 thats gets 25mpg is something to brag about, and i bet there is room for another 1-2 mpg improvement.. esp since it has a carb,
good job
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Dakota_Don]
#500618
10/22/09 12:46 PM
10/22/09 12:46 PM
|
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
|
Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
|
Quote:
Quote:
Quote:
Quote:
why build a 408 to run 13.5? Who care about mpg...make it run right and you might be able to pull a 13.0.
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.
Dang, Swingin', why you gotta rain on his parade? It's his daily driver. The guy built a combo with a good sweetspot he should be congratulated, not ridiculed.
Go put 4.88s in everything you own and poke your fuel tank with an icepick so you can use as much gas as you see fit.
hahaha no, not to rain but why build a 408 if you want mpg's? go buy a car that gets good gas milage.
a 408 thats gets 25mpg is something to brag about, and i bet there is room for another 1-2 mpg improvement.. esp since it has a carb,
good job
that is good.. I managed 17mpg at 75mph over a 35 mile drive. w/ my 340 swinger 3.55's 727 and with a 750DP carb tuned for max HP. and it ran 13.80 just saying..
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Jerry]
#500620
10/22/09 01:14 PM
10/22/09 01:14 PM
|
Joined: Dec 2004
Posts: 1,061
New Mexico
dmerc
OP
super stock
|
OP
super stock
Joined: Dec 2004
Posts: 1,061
New Mexico
|
Quote:
let me know when your ready to switch over to efi. get a tunnel ram bottom on there with a custom top and some nice atomizing injectors and you could probably see another 2-3 mpg with alot of tuning and a wideband. with the efi you can really dial in what your engine needs, plus you can adjust your timing based on what your engine needs.
Jerry, you don't know how much I'd like to do a FAST EZ fuel injection set up. It would be awesome! It's so darn expensive though. Got any low buck set ups for a buddy? 
I already use a LM-1 for tuning
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Jerry]
#500622
10/22/09 02:17 PM
10/22/09 02:17 PM
|
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
|
Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
|
That low first gear must really do wonders for helping getting things moving off the line. I bet it's making a lot of difference to your launch with those 3.23's. 3.23's with a 727 1st gear would be pretty weak in comparisin IMO. For the thermoquad, member DEMONSIZZLER sells a divorced electric choke assy similar to what the newer edelbrock carbs run. It's adjustable and bolts to the carb, not the intake. I find the thermoquad does deliver good mileage, however I've found it to give interesting results on the wideband o2. With the easily adjustable primary metering rod tree, it's not hard to tweak it to get your a/f's in the range you want them to be. What kind of idle a/f's are you getting with your thermoquad? I've found mine loves to idle lean when the motor is up to temp. FWIW I've got a megasquirt system nearly ready to go for mine as well. I really wanted to get it in the car this year, but between having R&R'd my motor for an overhaul and my transmission dying a slow death I just did not have the time to get around to it.  I bought my stuff a couple years ago already, but at the time I bought a MS-2 and a prefabbed harness from diyautotune.com I could have made the harness myself, but with the prefabbed one basically you just have to attach your sensor connectors and run the wires to where you want them. Looks like it'll save a lot of time, mess and thinking. 
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Jerry]
#500623
10/22/09 02:22 PM
10/22/09 02:22 PM
|
Joined: Dec 2005
Posts: 1,157
Cruising!
QuickDodge
super stock
|
super stock
Joined: Dec 2005
Posts: 1,157
Cruising!
|
Very impressive mileage figures! I'd love to have a car like that for regular driving. Overdrive transmissions are a great idea. Much more comfortable highway cruising. Old school folks can say what they want, but some newer components are better! I had an M-body years ago that came from the factory with a 2.2? ratio rear end. With a 3 speed 904, 998 or something like that it was a dog on take off. I never drove it on the highway, but a lot of M-body owners claim they can get 20+mpg with the 2.2 and 2.45 axle ratios. For what it's worth, some Camaro's came with an overall gear ratio of just under 2 to 1. With a 408 and a fairly light weight car, you could probably pull these kinds of gears. I doubt it would make much difference in gas mileage. If you happen to have an unused higher gear axle laying around and want to experiment.....I'd be interested in the results!!  Have you kept a record of average fuel consumption?
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: QuickDodge]
#500624
10/22/09 02:32 PM
10/22/09 02:32 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
|
Quote:
Very impressive mileage figures! I'd love to have a car like that for regular driving.
Overdrive transmissions are a great idea. Much more comfortable highway cruising. Old school folks can say what they want, but some newer components are better!
I had an M-body years ago that came from the factory with a 2.2? ratio rear end. With a 3 speed 904, 998 or something like that it was a dog on take off. I never drove it on the highway, but a lot of M-body owners claim they can get 20+mpg with the 2.2 and 2.45 axle ratios.
For what it's worth, some Camaro's came with an overall gear ratio of just under 2 to 1. With a 408 and a fairly light weight car, you could probably pull these kinds of gears. I doubt it would make much difference in gas mileage. If you happen to have an unused higher gear axle laying around and want to experiment.....I'd be interested in the results!!
Have you kept a record of average fuel consumption?
best I got stock with my 5th ave (2.2 rear gear) was 25mpg at a constant 75-80mph going across michigan on a warm summer day. more typical was 23.
my 5th with the 360 and loose converter with the 2.2 wasn't too bad on takeoff, was a little soft, but it was a beast from about a 15-20mph roll....
FWIW GmachinedartGT (I think that's his handle) has a stroker small block with a solid roller, he runs 26" tires, a 2.94 gear, and a 904. IIRC he gets ~17-18mpg running at freeway speeds, and can still click off low 12 second quarters...not bad considering his tire/wheel package and suspension is set up for handling, not drag.
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]
#500625
10/22/09 02:43 PM
10/22/09 02:43 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
|
Quote:
Quote:
let me know when your ready to switch over to efi. get a tunnel ram bottom on there with a custom top and some nice atomizing injectors and you could probably see another 2-3 mpg with alot of tuning and a wideband. with the efi you can really dial in what your engine needs, plus you can adjust your timing based on what your engine needs.
Jerry, you don't know how much I'd like to do a FAST EZ fuel injection set up. It would be awesome! It's so darn expensive though. Got any low buck set ups for a buddy?
I already use a LM-1 for tuning
I don't think the FAST EZ system is sophisticated enough to make it worthwhile, it's still a TBI system, so you have potential wet flow fuel distribution issues. it doesn't control timing. if you're serious about EFI, I'd go full multiport. batch vs. sequential is much less of an issue.
for your setup, I like jerry's idea of a tunnel ram base, build a plenumn and use a mustang, LS1, 5.7 hemi, etc style throttle body at the front or side. ford motorsports 30lb/hr injectors should feed your mill, and would be easy to come by on ebay or craigslist.
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: DaytonaTurbo]
#500627
10/22/09 04:30 PM
10/22/09 04:30 PM
|
Joined: Dec 2006
Posts: 3,533
Indiana
Fury Fan
master
|
master
Joined: Dec 2006
Posts: 3,533
Indiana
|
Quote:
FWIW I've got a megasquirt system nearly ready to go for mine as well. I really wanted to get it in the car this year... but I just did not have the time to get around to it. I bought my stuff a couple years ago already...
Misery loves company! I've got 2 MS units sitting on the shelf, for at least 9 months, and only need time to get it done. Just need a round tuit! 
It would sure be nice to find some more Mopar guys running Megasquirt (and a local guy would be a Godsend!)
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: patrick]
#500628
10/22/09 05:13 PM
10/22/09 05:13 PM
|
Joined: Dec 2004
Posts: 1,061
New Mexico
dmerc
OP
super stock
|
OP
super stock
Joined: Dec 2004
Posts: 1,061
New Mexico
|
Quote:
Quote:
Quote:
let me know when your ready to switch over to efi. get a tunnel ram bottom on there with a custom top and some nice atomizing injectors and you could probably see another 2-3 mpg with alot of tuning and a wideband. with the efi you can really dial in what your engine needs, plus you can adjust your timing based on what your engine needs.
Jerry, you don't know how much I'd like to do a FAST EZ fuel injection set up. It would be awesome! It's so darn expensive though. Got any low buck set ups for a buddy?
I already use a LM-1 for tuning
I don't think the FAST EZ system is sophisticated enough to make it worthwhile, it's still a TBI system, so you have potential wet flow fuel distribution issues. it doesn't control timing. if you're serious about EFI, I'd go full multiport. batch vs. sequential is much less of an issue.
for your setup, I like jerry's idea of a tunnel ram base, build a plenumn and use a mustang, LS1, 5.7 hemi, etc style throttle body at the front or side. ford motorsports 30lb/hr injectors should feed your mill, and would be easy to come by on ebay or craigslist.
IS THERE A TUNNEL RAM INTAKE THAT BOLTS UP TO MAGNUM HEADS?? Sorry about the caps.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: dmerc]
#500629
10/22/09 05:49 PM
10/22/09 05:49 PM
|
Joined: Nov 2007
Posts: 5,337
the house on the left.
cogen80
master
|
master
Joined: Nov 2007
Posts: 5,337
the house on the left.
|
Quote:
FWIW GmachinedartGT (I think that's his handle) has a stroker small block with a solid roller, he runs 26" tires, a 2.94 gear, and a 904. IIRC he gets ~17-18mpg running at freeway speeds, and can still click off low 12 second quarters...not bad considering his tire/wheel package and suspension is set up for handling, not drag.
i thought he said he went 12.7 and gets like 13 mpg.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Fury Fan]
#500630
10/22/09 07:01 PM
10/22/09 07:01 PM
|
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
|
Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
|
Quote:
Quote:
FWIW I've got a megasquirt system nearly ready to go for mine as well. I really wanted to get it in the car this year... but I just did not have the time to get around to it. I bought my stuff a couple years ago already...
Misery loves company! I've got 2 MS units sitting on the shelf, for at least 9 months, and only need time to get it done. Just need a round tuit!
It would sure be nice to find some more Mopar guys running Megasquirt (and a local guy would be a Godsend!)
Well maybe we'll get around to ours at the same time. Over the winter I at least want to finish assembling the MS unit, drill/mount my fuel rails and get some of the plumbing started so at least I'll be good to go next spring. 
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Fury Fan]
#500631
10/22/09 07:49 PM
10/22/09 07:49 PM
|
Joined: Jan 2003
Posts: 3,704
MICHIGAN
DynoDave
master
|
master
Joined: Jan 2003
Posts: 3,704
MICHIGAN
|
Quote:
Quote:
why build a 408 to run 13.5? Who care about mpg...make it run right and you might be able to pull a 13.0.
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.
Dang, Swingin', why you gotta rain on his parade? It's his daily driver. The guy built a combo with a good sweetspot he should be congratulated, not ridiculed.
Go put 4.88s in everything you own and poke your fuel tank with an icepick so you can use as much gas as you see fit.
 Thank you.
Sounds like a great combo dmerc!
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: dmerc]
#500632
10/22/09 08:20 PM
10/22/09 08:20 PM
|
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
Quote:
IS THERE A TUNNEL RAM INTAKE THAT BOLTS UP TO MAGNUM HEADS?? Sorry about the caps.
AFAIK the pattern is the same as any SB so I'd think a SB tunnel ram would fit.
Last edited by RapidRobert; 10/22/09 10:31 PM.
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: RapidRobert]
#500635
10/22/09 10:45 PM
10/22/09 10:45 PM
|
Joined: Aug 2003
Posts: 11,179
Atco NJ
DJVCuda
I Live Here
|
I Live Here
Joined: Aug 2003
Posts: 11,179
Atco NJ
|
Quote:
Quote:
IS THERE A TUNNEL RAM INTAKE THAT BOLTS UP TO MAGNUM HEADS?? Sorry about the caps.
AFAIK the pattern is the same as any SB so I'd think a SB tunnel ram would fit.
you could redrill a t-ram...
i bet my eddy street ram would be a good candidate
FWIW - I have 3.23's and a 26" tall tire, running 3400 @ 75 and get a best oof 16 and average of 14 ( playing with it ) with my t-ram and mild 360 - on the 300 mile round trip to Carlisle every year..
I also run 12.56 in the quarter.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: DaytonaTurbo]
#500636
10/22/09 10:50 PM
10/22/09 10:50 PM
|
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
I alway thought a TR would be unstreetable but there was a good thread a ways back & people shared that they are in fact VERY streetable w very little work & the visual appeal has gotta be good (or even a stub stack on a single carb sticking thru the hood).
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: hotlines]
#500640
10/23/09 06:47 AM
10/23/09 06:47 AM
|
Joined: Dec 2004
Posts: 1,061
New Mexico
dmerc
OP
super stock
|
OP
super stock
Joined: Dec 2004
Posts: 1,061
New Mexico
|
Quote:
I'm have a W2 head 340 roller motor with low compression in my 64 Signet and could sure use an OD, I have a built 700R4 sitting in my shop. Where exactly can I get the conversion stuff needed to pull this off. Thank you in advance 
Several ways to do it but I used a plate from Wilcap. The rest you have to fab up yourself.
|
|
|
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: 12,419
Kalispell Mt.
HotRodDave
I Live Here
|
I Live Here
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: 2,468
Answering the call of the wild
ThermoQuad
top fuel
|
top fuel
Joined: Aug 2003
Posts: 2,468
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.
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Hooligan]
#500664
10/25/12 10:53 AM
10/25/12 10:53 AM
|
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem
master
|
master
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
|
It's More to do with pressure. the high volume pumps tent to build more pressure and building pressure takes power so some parasitic loss! all ads up. But for safety at RPM a like a high volume pump with and light or adjustable releif spring so you can set your max pressure at say 65 not 110 but it still has the volume when called for. this is with 1/2 15/40 and 1/2 5W 50 motor was cool http://www.youtube.com/watch?v=kmvZNkBHfUU&feature=plcpthis was on enital start up this summer went to 68 I think dead cold. Course the alt quit just as I mentioned it wireing issue took ot the regulator all fixed now. http://www.youtube.com/watch?v=YvhENA8svJY&feature=plcp
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: Jerry]
#2814065
08/27/20 07:42 PM
08/27/20 07:42 PM
|
Joined: Jul 2008
Posts: 30,431
Florida STAYcation
BeEtLeJuIcE !
The village idiot's idiot
|
The village idiot's idiot
Joined: Jul 2008
Posts: 30,431
Florida STAYcation
|
Did someone say larryLOVEits 408 was getting 25 plus ? With THAT FACT and his installation of those greyvvelore seats ... I’ll bounce my offer up aNutter 1k$ 
|
|
|
Re: 25 MPG with a 408 ??? Yup!!
[Re: BeEtLeJuIcE !]
#2814186
08/28/20 12:19 AM
08/28/20 12:19 AM
|
Joined: May 2003
Posts: 3,065
N.W. Florida
Fat_Mike
master
|
master
Joined: May 2003
Posts: 3,065
N.W. Florida
|
Did someone say larryLOVEits 408 was getting 25 plus ? With THAT FACT and his installation of those greyvvelore seats ... I’ll bounce my offer up aNutter 1k$ Hey Bro! Not sure what brought this up tonight, but 8 years ago was "in the past." Dudes don't talk about that stuff...
|
|
|
|
|
with hopes for some updates 
