The Idea!!!!

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Tbone416

Tbone416

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Ok here we go my idea is to build a car that can be driven daily and get good gas mileage! So I have a 1968 4 door dart that I got from my good buddy MikeBee. The dude he got it from sold all the parts of it that wound fit on 2 door but the body was rust free. So Mike couldn't kill it. It doesn't have fenders bumpers motor trans and a lot of other sh*t. So I can do what I want with it maybe slant 6 with a 4 speed overdrive or a 2.4 with a 5 speed or maybe a auto trans. I'm thinking glass hood,fenders,trunk,and bumpers. And I'm looking for 30 mpg's I don't think it shouldn't be to hard they say that dart lites got 36 hwy. So what's your thoughts?:tard::usa2:
 
AJ/FormS said:
I hope that you are young and have loads of free time. Thank goodness its rust-free.All the best to you.
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I'm 46 and have been working on cars a long time I was 25 when I started to work with dodge so I'm good but thanks!:glasses7:
 
Don't see why with a 2.4/5 speed you couldn't easily get 30+ the srt-4 neons do it all day long.
 
30mpg might be tough. The 2.4 seems like it would be the better option for getting that to happen. You'd also have to try and keep the car as light as reasonably possible.
 
75slant6 said:
Don't see why with a 2.4/5 speed you couldn't easily get 30+ the srt-4 neons do it all day long.
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you think the turbo would help or hurt the gas mileage I don't care about performance I have a challenger and a GTX for that.
 
magnumdust said:
30mpg might be tough. The 2.4 seems like it would be the better option for getting that to happen. You'd also have to try and keep the car as light as reasonably possible.
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yes I was thinking about the aluminum slant 6 and the fiberglass parts with aluminum wheels. I think I could maybe get to 2400 lbs and the bigger motor mite not have to work as hard as the 2.4
 
A stock srt-4 neon has a curb weight of 2900 pounds. A stock 68 Dart 4 door has a curb weight of 2866 pounds. Subtract the weight saved by using glass body parts and the fact that the 2.4 weighs considerably less than a slant 6 and your car should be a few hundred pounds less than a stock neon. I'd think 30mpg should be very doable! But I've never messed with anything like this so I wouldn't know for certain. I do know that there is a 67 valiant 4 door in a local 'yard that I want to do this very swap to some day tho! So get it done n let me know the results!! Lol
 
Tbone416 said:
I think I could maybe get to 2400 lbs and the bigger motor mite not have to work as hard as the 2.4
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I had a 98 neon for awhile that had a non-turbo DOHC 2.4 in it that was stock bore and stroke, had the balance shafts deleted, 2.0 cams, 2005 mustang injectors and a cold air intake and I dare say that thing would whoop any stock slant, it sure moved that neon along pretty good!! I've been told the srt4s can make 400hp pretty easily with a stock turbo.
 
I have a 2.4 out of pt cruiser and the man down road has a turbo 2.4 out of one I don't know about the trans could be tricky
 
Contact rapidtransitric about the swap. He's currently swapping a 2.4 into an early 60s valiant.
 
If your looking for a little performance and mileage I'd go 273 if you just want mileage I'd go with170 and the a833 OD tranny and the highest rear gear you can get on either.

Weight and aerodynamics will be the ultimate factor
 
273 said:
If your looking for a little performance and mileage I'd go 273 if you just want mileage I'd go with170 and the a833 OD tranny and the highest rear gear you can get on either.

Weight and aerodynamics will be the ultimate factor
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I don't care about performance I have other cars for that but I have a 318 2 barrel and 833 od tranny but I don't know what kind of gas mileage I could get
 
Tbone, if you are going to go with a glass front end and trunk lid, I suggest having a front chin spoiler or splitter molded in and a direct connection style spoiler on the deck lid. Cleaning up the air flow around the car helps a lot for gas mileage. You might also have a bottom engine compartment cover made to smooth out the air under the car. These were some of the tips that were published back in the 1970s when we had the gas crisis.
 
Sometimes the bigger motor improved mpg. I know it doesn't make since at first but I had a 94 ranger with a 4.0 v6. My roommate had a 94 with the 4 banger. I averaged five more mpg then him. Both trucks were standards and mine actually had the back seats as where his was a single cab. I attributed this to my motor not having to work nearly as hard as his to get the job done. It may have been something else but that's just my .02
 
Tbone416 said:
I don't care about performance I have other cars for that but I have a 318 2 barrel and 833 od tranny but I don't know what kind of gas mileage I could get
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This would be my vote, but the 318 would need some work like the better 302 heads raise cranking psi to whatever reg can handle maybe 150lbs, maybe a aluminum intake with a small 500 cfm carb, headers,
 
doogievlg said:
Sometimes the bigger motor improved mpg. I know it doesn't make since at first but I had a 94 ranger with a 4.0 v6. My roommate had a 94 with the 4 banger. I averaged five more mpg then him. Both trucks were standards and mine actually had the back seats as where his was a single cab. I attributed this to my motor not having to work nearly as hard as his to get the job done. It may have been something else but that's just my .02
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4 cylinders usually have deeper gears so they turn more rpm for any given speed.
Say a 2l has twice the gearing as 4l they would consume about the same fuel and air.
Also hp at speed is another factor say at 60 mph the 2l turns 3000 rpm and makes 100 hp
And the 4l turns 2000 rpm and also makes 100 hp they would both burn about the same mpg
Cause it takes about the same amount fuel and air to make 100hp.
Obviously I left out engine efficiencies in these examples.

And when I asked about performance I was talking reasonable power level for driving style.
I hate gutless cars and find they burn more fuel cause I push them harder like the 4 cylinders vs v6 above.
With the 273 you could easily build a 200 hp plus engine which is a decent amount of power and probably only lose a couple mpg if any over a slant 6. And the average car only needs about 50 hp to push it to highway speeds so anything above that is technically a performance engine.
 
The square box shape of the car will defeat your efforts at speed.
You would be better off putting the slant in the neon body and going for 40 mpg
I just read this whole thread and can't figure out why you would want to put a 4
cyl in a 68 dart. Then the added weight of 2 extra doors. The slant is underpowered to the point it is almost dangerous on the interstate in this body. They won't run the 70 mph for any distance worth getting out there. I have scattered so many of them engines trying to make them keep up with the posted speed limit in a design that is best tooling around town. Forget about passing.
Now dont get me wrong, I am a Mopar guy all the way. But none of the engines you
mentioned will live a long healthy life with a 70 mph wall of air the size of a 68 dart pulling them down.
That has been my experience with these old square bodies and small engines. Their are much better ways to get 30+ mpg.
Have a friend that has a 68 dart with slant take you out on the hiway before you invest your money. You will feel like your going to get run over out there with all the trucks and cars blasting by. Not a fun driving experience. Ask me how I know? I have been there to many times.
 
magnumdust said:
30mpg might be tough. The 2.4 seems like it would be the better option for getting that to happen. You'd also have to try and keep the car as light as reasonably possible.
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^^^^

auto trans only if you do a lockup converter. otherwise stick with the 4 speed.

smaller motors will get better mileage but you should still get over 20mpg with a properly tuned 318. but again with a V8 you are bringing a lot of weight with you also.

3.23 or 2.76 rear
 
Mostly stock 318 with that OD transmission would be my choice. They easily got in the mid-20s MPGs back in the day. You could put on EFI, and electronic ignition, headers, good exhaust system, and you might hit 30 MPG on the highway if you take it easy. 4 or 5 speed automatic with computerized lock-up converter maybe? And it would still be pretty peppy around town.
 
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