MPG experiment, 1976 Dart Lite

[skyl4rk]

This is a fun build. I used to drive slant 6'es, and had a few Valiants and Darts. Most of my cars were purchased for $500 or less. I will admit that I treated them as disposable vehicles, and drove them till the rust ate them up, and didn't really look at them as a restoration project. I remember getting mpg in the low 20's, this was back in the 80's and 90's.

The timing chain replacement really livens up the motor. You can tell if you need a timing chain by looking at the timing mark with a timing light. Hit the accelerator and check how far the timing mark bounces back and forth. After the motor slows down to an idle you can still see it bouncing if it is old and stretched out. Actually you don't even need to do this. If you have an old timing chain, you need a new one. It turned my tired old motor into a, well, not a powerhouse, but a responsive economy motor.

Checking and adjusting valve clearance is an easy job that should take less than an hour or two. If you have some clicking, you should be able to fix the noise and improve how the motor runs with a simple adjustment.

The other big thing on the 225 is to keep your PCV valve clean and/or replaced. They tend to gum up.

I always liked working on the slant 6 and greatly prefer straight (or in this case slant) 6'es to any other motor type. My favorite 6 was a Chevy straight 6 in a 1964 Studebaker with 3 on the tree. Simple, reliable machines with plenty of room to work on them.

[Backtobasics]

CEEJ,
The carb had a 62 jet in it. I swapped in a 64 (smallest in the box) to see what it does.
I did not notice any appreciable difference in the behaviour, so we will see over this tank if it keeps it out of the power valve.

Valves were run recently and no noise so far. I adjusted them running, others use feeler gauge when off, but they are quiet and it idles smooth for now.

I just got the PCV hooked back up, and we blasted it out with carb cleaner, so it is clean. Next parts store trip I will get another, but there is NO blow by coming out the vent, so it appears to be doing the job!

Timing chain is in the plans, seems as if it is a problem area.

[ceej]

Cool! Keep us posted on your progress!

A true spread bore two barrel that is readily available is the Rochester 2SE. It was used on the Chevy S-10 and Jeep Cherokee's that ran the 2.8L v6.

The pattern is pretty different. I'm not sure how you would make it work other than going aftermarket intake and build your own carburetor plate.

If you look into the Rochester, be careful not to snag the E2SE. It is a computer controlled version that was used for three years or so while GM was shifting from Carburetors to TBI. It allowed them to meet the emission requirement short term and bridged the gap.

It's not that the E2SE isn't a pretty good little carburetor, it's all the other stuff that would be required to make it work.

Some of the Japanese carbs could also be made to work on your slant. Similar issues would poke their noses up though.

Mainstream would be to go with the Holley 390, but you're going to want a bit more compression to make things work. The 4bbl will get you into the 23mpg range, but an extensive recurve would be needed for the Distributor.

Some folks have run the Holley 2300 series to good results. The 350 cfm model is just about right for a street car. The 500 cfm is a drag race only item that needs extensive engine mods to work well with the Slant Six. My Valiant launches harder with the 500 cfm 2 bbl than any other carb I've had on there.
Mid 20's with the 350 cfm. Not as many mods required to use it. The Offy, Clifford, or Aussie intake manifolds would be the trick there. Best for lower RPM torque would be the Offy in my opinion. Smaller runner cross sections. Top end would be the Aussie. The Clifford sports carb heat for Header applications and can deliver good numbers on both ends of the spectrum.

Another option is the Weber DGEV or similar. It gives you progressive, and there are manifolds out there for it. It's on the smallish size for the displacement, but should give terrific throttle response, and good road power. At the strip your going to run out up top, but that shouldn't be a concern with the build your talking about. I think Lynx makes the intake manifold for it. They also make manifolds for single, double and triple DCOE's, a dual DGEV and various configurations of SU carbs. (Which once you get used to the tuning procedure, aren't so bad, just not readily available on this side of the pond.)

HEI is really going to give you a better burn. I'm prepping to dump my Mopar EI this winter once the racing season is over.
For a clean burn, multi-spark boxes can't be beat. The Mallory box is a bit less money than the MSD, and works fine. Move the coil from the stock location on the head onto the fender. Look at an aftermarket coil choice. There are a lot to choose from, just make sure you match the coil, distributor and EI to an appropriate Ballast resistor. Not all parts play well together.

Too bad your half way across the continent, or we'd get you in the driveway and get busy!

CJ

[Backtobasics]

In the short term I am going to try to maximize what I have. The 1945 has a recent rebuild, and runs pretty well.

I am going to use an Offy for down the road. The carb is a 0-6210 Holley, spread bore double pumper, 650. (Duck and cover)
I know it's big, but when the turbo comes it is one of the smaller carbs that work for blow through. I will likely on my little engine, lock out the secondaries, as primaries should be adequate.

HEI mod is coming soon. It sounds like the next logical step. I have access to MSD, Mallory, and all the performance stuff through work. A max ignition system will help with boost down the road.

I may look into one of the OE distributors that Dan recommends. I emailed the old parts dude, no answer yet. I half wonder if going to non DL and FD distributor, would allow me to start with a 1976 non lightweight build, and go from there.

I am dying to get my exhaust run. I am tired of the existing stuff banging and clanging.

Electric fan is coming soon, especially with colder weather, no need to slow warmup, and eat HP turning fixed blades. If it stays cool, then I might fashion up one of these high fangled grill blocks I read so much about!
Even with the distance, we will get it tuned. I am anxious to see what the next tank will bring, with the working PCV, no vacuum leaks, larger jet, etc.
Thanks for all the help.

[ceej]

You might look into modding a 500 cfm Holley 2300 for the blow through. There are some mods needed, but your not hauling around a second float bowl of fuel that isn't pulling it's weight.

I haven't seen a spread-bore plate for the Offy. Doesn't mean there isn't one. I have a square bore plate on mine.

Clifford makes a plate for square and two barrel applications. Next time I take things apart, I'll see if my Clifford plate really bolts up to the Offy intake like some folks say...

The 500 is a lot of carb for a stocker, but once you get some boost on, it'll work very well. They are easy to richen up for forced induction. It's basically the same process as for the double pumper, but you don't have to mess with the Secondary circuits!

CJ

[Backtobasics]

UPDATE:
Dropped to 17.45.
I updated fuel log, not sure how to make it show on the graph.
The change was jetting, went from 62 to 64 to try to keep out of power valve. The results are what I expected, as it appears the 62 is the "larger jet" people are using stock is 58-60? I am going back to 62 tonight, and will try to check out timing chain condition, maybe advance timing a bit.

[Backtobasics]

Returning from the dead:

In the famous words of the monkey in the Lion King... It is time.

The Dart Lite is coming out of hibernation. I got better MPG out of it then I do my truck, and with gas as stoopid as it is now, it is time to bring out the DLITE.

I have picked up a "Super Six" setup that is 2 barrel carb, intake manifold, air cleaner, and exhaust manifold (rumored to be larger, not sure). The carb will get a kit over the next couple days, and then I will swap parts. I plan on throwing a replacement timing chain on at the same time, adjusting the valves, full igniton tune and HEI upgrade, etc.

2nd phase will be low budget rebuild on the spare /6 in the garage, mate it with the 4 speed OD, and see what kinda MPG I can pull with the OD.

[War_Wagon]

I saw a Feather Duster last week, was that an economy model as well? My friend had a Hang Ten Duster in high school, but I think that was just the sunroof / folding back seat option wasn't it?

[Backtobasics]

Feather Duster = Dart Lite, yep.

Hang 10 was option package, usually white interior with red striping, sun roof, fold down rear seat, etc, as I recall.

[War_Wagon]

There is a trashed Al Bundy special Gold Duster parked on the side of the road near here, that wouldn't be a factory lightweight/economy car would it?