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93EXCivic
93EXCivic UltimaDork
5/17/12 6:46 p.m.

Ok what can GRM tell me about old Dodge Darts (62-76)? What kinda mpg did a slant six version get? What could you get (mpgs) with mods (like fuel injection and 5 speed transmission)? How bad an idea would it be to DD one? Also does anything about the Dart apply to the Valiant?

93EXCivic
93EXCivic UltimaDork
5/17/12 7:11 p.m.

Also can you make them decent in the corners?

Dr. Hess
Dr. Hess UltimaDork
5/17/12 7:26 p.m.

I recall a guy at work (circa 1979) that had one (slant 6). He could hang with my 472 V8 on the LA freeway system and he said he got in the 20's, like maybe 22, 24, if I recall. I got about 8. And I think that as with all inline sixes, they are as reliable as a hammer.

Stealthtercel
Stealthtercel HalfDork
5/17/12 7:42 p.m.

slantsix dot org is your friend. Most of what you want to know is there somewhere. There is a pretty huge aftermarket, even subtracting the number of people who want to help you yank the /-six and "drop in" a hemi.

Mopar A-bodies are legendarily indestructible as cars, but I don't know how they rate if you look at them from a modern safety standpoint (if that's an issue for you.)

93EXCivic
93EXCivic UltimaDork
5/17/12 7:43 p.m.
Stealthtercel wrote: but I don't know how they rate if you look at them from a modern safety standpoint (if that's an issue for you.)

Meh I am young and dumb.

Stealthtercel
Stealthtercel HalfDork
5/17/12 7:52 p.m.

OK, but I assume there are people who love you who want you to stick around to be old and dumb!

On the plus side, I also gotta assume that your average Dart bumper (made of good old American steel) should take care of a LOT of 21st-century impacts.

Don49
Don49 Reader
5/17/12 8:20 p.m.

I had a 64- 3 speed stick witht the 170 engine and got 28-30 mpg with it. I advanced the timing and ran premium. They can be made to handle suprisingly well. My 66 Dart wit 225ci auto and better shocks/ 14" tires would outhandle most sports cars of the era. Cool cars and very well balanced. I almost forgot to mention my 1960 Valiant with the 170ci and auto. It was somewhat ree-worked and would pull to 7200 rpm's and spin the tires shifting into 2nd at close to 60 mph!

stroker
stroker Dork
5/17/12 8:23 p.m.

You need to go to the Mopar Action website and look up everything you can find on the Green Brick and Richard Ehrenberg. They ran the One Lap a few times and that car is quite quick. I used to follow Slant Six stuff pretty actively until I sold mine. I aspired to having an early A-Body but Mad Scientist Matt and Mopar Rob are your friends with this.

ProDarwin
ProDarwin SuperDork
5/17/12 8:32 p.m.
93EXCivic wrote: Ok what can GRM tell me about old Dodge Darts (62-76)? What kinda mpg did a slant six version get? What could you get (mpgs) with mods (like fuel injection and 5 speed transmission)? How bad an idea would it be to DD one? Also does anything about the Dart apply to the Valiant?

Mileage - not very good. I had 2 Slant Six Valiants (225s). 20mpg was a miracle.
With fuel injection and a 5 speed, things would change a lot. Probably low-mid 20s.
They are really simple, so once you know your way around them, DDing wouldn't be terrible. They are very slow, squishy, and have awful brakes. Nothing from the factory would be adequate for an "enthusiast".
Almost everything Dart and Valiant is the same.

I still fantasize about a EFI turbo slant six. I was working on one back in the day, but scrapped it.

Rob_Mopar
Rob_Mopar Dork
5/17/12 10:04 p.m.

I'll try to keep from writing a book here, I need to get up early tomorrow.

And I'll leave the EFI question to Matt. But a T-5 behind a Slant would be very nice, and fit the tunnel well.

My Barracuda is the same chassis as a '67-76 Dart. Barracudas from '64-69 were A-bodies. Wheel base was shorter on the Plymouth vs. Dodge until '71 then there was overlap (Scamp shared the Dart Swinger 111" wheelbase, Dart Sport shared the Duster 108").

I have a '68 Dart in my shop now. It's a customer's car. Stock 225, auto, 2.76 gears, manual steering, soft suspension and drum brakes. It's been a while since I drove a stock one. We're just fixing some things that never got fixed before the previous owner's husband passed away and the car was parked.

The stock suspension is soft. Makes the car feel much larger than it is. Quite comfortable, but not exactly my taste. The manual drums stop the car well, but leave room. Slow manual steering has good feel but you need to remember that you need to rotate the wheel a whole lot more to make that turn.

It's fun to drive as a cool nostalgic cruiser when you want to travel a little back in time going down the road. That's why he wants it. He also has an S2000 at home. The Dart would be a fine daily driver, but what people expect out of cars has changed a whole lot in the last half century.

My Barracuda is much more modern feeling. I installed much larger torsion bars (1" dia), front sway bar (1 1/8"), stiffer rear leafs (still experimenting for the perfect combo, but these are good), adjustable shocks, 11 3/4" front disks, and 10x2.5" rear drums. I'm also running a Firm Feel Inc stage 2 power steering box (15.7:1 ratio). My headers don't allow enough clearance for the longer pitman arm and idler to bump the ratio up a little further.

I've dodged cones with the car and run it on the drag strip. It handles very nice and doesn't beat you up. I've thought about building a 3-season A-body a few times. I can't bring myself to subject one to road salt. Not that they will dissolve, but if they have made it 40 years or more now, they deserve a chance to keep going.

As has been mentioned, E'bergs Green Brick in Mopar Action is probably the best known handling A-body on the internet. Rick has run in in One Lap many, many times. The evolution of the car has been chronicled in his magazine.

I'll only be accessing the computer at night for the next three nights. I'll answer whatever I can when I can. So any questions, ask away!

93EXCivic
93EXCivic UltimaDork
5/18/12 7:12 a.m.
Stealthtercel wrote: OK, but I assume there are people who love you who want you to stick around to be old and dumb!

Yeah I know it would probably be a nice day Daily driver not everyday. Plus I figure lots of people drive motorcycles everyday and the Dart has lots of metal surrounding me so it has to be safer then a motorcycle. I figure you only live once and you have to enjoy it and part of that to me is enjoying cars and sometimes that is taking calculated risk.

93EXCivic
93EXCivic UltimaDork
5/18/12 7:16 a.m.
Rob_Mopar wrote: My Barracuda is much more modern feeling. I installed much larger torsion bars (1" dia), front sway bar (1 1/8"), stiffer rear leafs (still experimenting for the perfect combo, but these are good), adjustable shocks, 11 3/4" front disks, and 10x2.5" rear drums. I'm also running a Firm Feel Inc stage 2 power steering box (15.7:1 ratio). My headers don't allow enough clearance for the longer pitman arm and idler to bump the ratio up a little further.

Where are the disc from? Are there junkyard upgrades for brakes? What shocks are decent?

As far as engine upgrades what are decent upgrades which won't kill mileage?

slantvaliant
slantvaliant Dork
5/18/12 7:56 a.m.

Darts are just nearly as good as Valiants of the same era. Seriously, they share most hardware. Wheelbases and some body parts differ. There are "Dacuda" phantoms out there - Dart front ends on early Barracudas:

93EXCivic wrote: What kinda mpg did a slant six version get?

All over the map. Worn out engines with lousy tunes and driven sloppily are in the low teens. About 20 MPG is common, mid 20's aren't too hard. The Dart Light and Feather Duster with Slant Sixes and manual transmissions gamed the EPA ratings to get 36 MPG on paper.

My last trip yielded 21 MPG average for 600 miles with the car loaded and the AC on most of the way. Some of the well-developed performance cars report 25 MPG with EFI.

Another vote for hanging out over at the Slant Six Forum (slantsix.org). Read the articles, and search the forum. TONS of info there.

pres589
pres589 Dork
5/18/12 7:57 a.m.

Weber 32/36 or Holley 5200 or Motorcraft whatever, all the same carb, on a factory 2-barrel intake. It's talked about on the web here & there and if tuned well could net better power and mileage at once. Electric ignition using factory parts if the car in question doesn't have it already. There's headers out there and probably worth a look.

For what it's worth, I pulled low-20's in mixed driving with my Savoy; 225, automatic, and no tuning work. A Dart should do the same if not slightly better (a factory stripper Savoy is a fairly light car and I had no power anything). I believe the factory light weights like the Feather Duster were rated at 30mpg on the highway. An overdrive of some sort like the Feather Duster's A833 o/d trans would be a great swap, a T5 wouldn't be bad either although I wish top was a little taller in my Mustang. Maybe with a smaller six it'd be a better compromise.

I think a well built 225 with the engine deck cut to get the pistons near zero and some head work done could really help these things make power and improve economy; the stock compression ratios are pretty low. The head isn't a cross flow and the factory exhaust manifold is pretty poor looking, the intakes are better but not great. Port EFI, some compression and a good exhaust would probably do a lot of good but not many folks throw that kind of money at a Slant Six.

slantvaliant
slantvaliant Dork
5/18/12 8:05 a.m.

BTW, a V8 Dart won the first Trans Am (in the over-2-liter class, anyway.) So, yeah, they can be made to handle.

MadScientistMatt
MadScientistMatt SuperDork
5/18/12 9:55 a.m.

With multi-port EFI, I'd expect mileage to pick up maybe 10-15% with good tuning on its own. It would probably get even more gains from an overdrive coupled with EFI than EFI on its own.

93EXCivic wrote:
Rob_Mopar wrote: My Barracuda is much more modern feeling. I installed much larger torsion bars (1" dia), front sway bar (1 1/8"), stiffer rear leafs (still experimenting for the perfect combo, but these are good), adjustable shocks, 11 3/4" front disks, and 10x2.5" rear drums. I'm also running a Firm Feel Inc stage 2 power steering box (15.7:1 ratio). My headers don't allow enough clearance for the longer pitman arm and idler to bump the ratio up a little further.

Where are the disc from? Are there junkyard upgrades for brakes? What shocks are decent?

As far as engine upgrades what are decent upgrades which won't kill mileage?

Yes, there's a lot of junkyard stuff out there. I believe Rob is talking about the late '70s B or R body (Cordoba, Charger, St. Regis, Newport, any of your really big land yachts) swap. You can also put F/M/J body (Aspen, Diplomat, Volare, etc) brakes on, which aren't quite as big.

KYB Gas-A-Justs are OK budget shocks. QA1 makes some better bolt on shocks if you want something more in the Koni performance and price range.

Other than EFI, the biggest engine mods I can think of that won't compromise fuel economy would be milling the head for more compression and a free flowing exhaust with headers or a split Dutra manifold (headers may take some retuning as well). Also note that two barrel carbs seem to get better mileage than the stock single barrel.

ProDarwin
ProDarwin SuperDork
5/18/12 10:03 a.m.
MadScientistMatt wrote: Also note that two barrel carbs seem to get better mileage than the stock single barrel.

IIRC the later 70s cars were available with OEM two bbl. My '74 had one.

volvoclearinghouse
volvoclearinghouse Reader
5/18/12 10:29 a.m.

I drove a '63 Dart convertible for a few years. Used to average 22 to 25mpg with the /6 engine, and the convertible was heavier and had 2.94 gears (stock was 2.76 IIRC). One time I got near 30mpg, cruising around 45 mph for a few hours. It would keep up on the highway, too- 85mph was about top end. The engine seemed dead solid.

Chrysler power steering in the 60's and 70's was that single-finger type that some really like, and others don't. I have a '64 awaiting a heart transplant that has manual steering; I expect it to be like all the other American cars from the period with manual steering- lots of turns lock to lock.

Drum brakes aren't bad- on that light of a car I made plenty of stops from highway speeds. But your later Darts had disc options, and they do stop better. But, if you prefer the styling of the earlier stuff, there are junkyard retrofit options.

Cruise eBay for a 2bbl carb intake. Some were aluminum- these command more $$ and can be leak prone. A decent cast one will run you ~$125. Exhaust- split the front and back three cylinders. Run them as far back as you can before joining them- or just run duals. It sounds much better and gives a lot better breathing. Pretty much all those old log exhaust manifolds suck. But the /6 does at least have decent intake geometry, for a non-cross flow head. Like some have said, shave your heads, 9:1 compression or even a little more is good. There's better cams out there, too. And small block radiators.

The 904 trans behind the /6 is a great little automatic. Install a good aftermarket cooler and it should last a long, long time. i don't have any experience with the manual transmissions but I don't know of any issues with them, other than heavy clutches.

Safety? Make sure the car's in good mechanical shape and drive defensively. The best safety device ever invented is the driver.

slantvaliant
slantvaliant Dork
5/18/12 10:40 a.m.
MadScientistMatt wrote: Other than EFI, the biggest engine mods I can think of that won't compromise fuel economy would be milling the head for more compression and a free flowing exhaust with headers or a split Dutra manifold (headers may take some retuning as well). Also note that two barrel carbs seem to get better mileage than the stock single barrel.

I'd add electronic ignition. Yes, a sharp tune on points can work well. But a good electronic ignition is much more consistent over time, and should contribute a little to mileage. Besides, I hate fooling around with the distributor on a Slant in a narrow-body A.

I'm running HEI. Yep, GM module with a Chrysler EI distributor.

93EXCivic
93EXCivic UltimaDork
5/18/12 11:02 a.m.

What about A/C? Do these cars have it available?

MadScientistMatt
MadScientistMatt SuperDork
5/18/12 11:20 a.m.
93EXCivic wrote: What about A/C? Do these cars have it available?

They did, although it's not a common option. You can get aftermarket units as well:

http://www.slantsix.org/articles/vintage-air/Vintage_Air.htm

Gasoline
Gasoline Reader
5/18/12 11:29 a.m.

I think one would be cool with an aluminum block slant six. They made 45,000, just have to find one.

http://www.slantsix.org/articles/dutra-blocks/alm-block-sl6.htm

slantvaliant
slantvaliant Dork
5/18/12 11:38 a.m.
93EXCivic wrote: What about A/C? Do these cars have it available?

My '64 had a period aftermarket unit. Last year I replaced it with a modern (R134, parallel flow condenser) unit intended for an early Mustang, from Southern Air. The evaporator looks a lot like the old one. They let me have a Sanden/York adapter instead of the Ford six compressor bracket.

Gasoline
Gasoline Reader
5/18/12 11:45 a.m.
poopshovel
poopshovel PowerDork
5/18/12 12:44 p.m.

Holy secksonwheels. Why am I just now hearing of this!? That is beautiful.

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