Mopar 440 ideas?

[Homerr]

I'm planning my build of a 1970 Charger and would like a stock look under the hood. This means a big-block 440, not a modern 5.9 or later swap. It doesn't need to be concourse looking, some extra plumbing would be okay. I don't have the motor yet, and it probably means getting a greasy craigslist core to have built.

The plan is to drive cross-country with my wife in it - so stinky & loud are out. I'd like show the car a bit too. I'll run stock tire size, stock ride height, and run a taller gear (2.76) with a 5-speed. I'd like to use a F.A.S.T. EZ-EFI 2.0 (or similar) system that will fit under a stock air cleaner. These have an O2 sensor. I'm open to and expecting catalytic converters. I also expect some tuning on a dyno. The heads will be rebuilt with hardened valve seats so I'll run 92 octane unleaded and adjust compression downward. Otherwise a fairly stock rebuild is planned.

I'd like to attack both emissions and mileage, with an edge toward emissions. Most of the MPG control is going to be keeping my right foot out of it. In my limited research I'm seeing that 3-way cat's use an O2 sensor to control HC, CO, and NOx. The EFI would keep the 14.7:1 ratio in line. I know it's still going to be a bit of a pig in the fuel mileage department, but if I can make a decent attempt at addressing the emissions it will set my mind at ease a bit.


1. Given all that, does anyone have suggestions or experience taking an old motor and improving emissions like this? (Hot Rod's 'Crusher Camaro' started out as this in the mid-90's apparently but they seem to only have 2009 and later stuff (which is all less eco) online now.)

2. Is my assumption of catalytic converters a given?

3. An air pump seems like those were used with 2-way cat's. I don't need one, right?

4. Is it likely that I need to add an EGR valve? (addressed at dyno time?)

5. Is there anyone in the greater-Seattle area that is recommended for this work?

Basically I'm looking for a formula, but I'm not sure one exists. Thanks for any help!

[gone-ot]

Available Mopar axles back in 1970's were 2.73, 3.18, 3.23, 3.55...so maybe consider looking for a 2.73 for lower RPM's at cruising speed.

[cosmick]

I've heard of the 2.76:1 you mentioned for the old 8.75" Mopar axles. If you want to keep a correct axle, then that's as good as it gets. That, with a TKO 500, should drive very well.
Choose a cam with no overlap at 0.050", dual-pattern if not getting aftermarket aluminum heads. Order headers with the smallest tubes, then get them ceramic coated inside and out.
EGR is worthwhile IF Edelbrock offers such an intake manifold. No need for the air pump.

[320touring]

I'd just crate up the 440 and send it over here for me to install in something wholly inappropriate

I honestly could not hypermile such a thing-too good a sound to drive sensibly but best of luck with your endeavours

[Homerr]

Well, hypermiling a mild 440 might net ~15mpg.

Years ago I had a '69 Charger with a built 383 that did a best of 13mpg on a highway run, 8mpg was normal around town. I was younger and the environment was hardly a 'thing' back then. I've spent the last 25 years driving econo-cars, car-pooling, riding a bus, and riding a bike so I feel like I've made some amends. I'd like to do it a little more responsibly from the get go this time around.

[cosmick]

Under-ambitious. I know a guy with a 454 and a built 700R-4 in a '66 Chevelle that's done over 20 MPG more than once. 3.08:1 12-bolt posi and 235/70R15 tires on 7"-wide wheels. That's with an Edelbrock 750 carb, tuned lean, the old way, without a wide-band exhaust oxygen sensor.

[Homerr]

I'll take that! I was trying not to oversell a 440 since I've been out of the Mopar realm for quite a while.

[darcane]

I believe the air pump was needed for carbureted engines in order to keep the mixture flowing into the catalytic converter lean enough to not kill it. If the EFI has an O2 sensor, I don't think an air pump will be required.

My guess is that nearly everywhere you go, you will be told it's a bad idea. Maybe try Stan's Headers in Auburn. They are probably used to getting oddball requests and could point you in the right direction even if they don't do the exhaust work themselves.

[darcane]

Originally Posted by Homerr

Well, hypermiling a mild 440 might net ~15mpg.

Years ago I had a '69 Charger with a built 383 that did a best of 13mpg on a highway run, 8mpg was normal around town. I was younger and the environment was hardly a 'thing' back then. I've spent the last 25 years driving econo-cars, car-pooling, riding a bus, and riding a bike so I feel like I've made some amends. I'd like to do it a little more responsibly from the get go this time around.

I have a '68 Chevy C10 pickup with a 400SBC and Holley Pro-Jection EFI (<--- utter crap. Modern aftermarket EFI is much better). With my old 5-speed and 4.10 gears, I got 15mpg hwy consistently driving normally. I would think a mild 440 with EFI and a 5-speed should do 15mpg without much trouble.

[Hersbird]

Emissions are a problem with the 440, why they went to the V-10 for big block torque because those huge cylinders don't burn well. Add to that probably the only cams out there are stock or bigger it only gets worse.
What would help it is compression, the problem there is bad fuels but how about this idea, an E-85 440? Build high compression, use inexpensive E85. The biggest problem is it's not available everywhere so you would need some octane additive just in case and a way to adjust the tune on the fly.
Another option would be a propane conversion, also high octane and available everywhere but a bigger pain to refuel.
A 383 would also be a better choice and looks almost the same as a 440. I'm a Mopar guy and don't think I could tell the two apart.
These suggestions are all based on emissions as a priority. Personally I think on a hobby car from 1970 which isn't used as a commuter in a major metropolitan area the emissions are insignificant. Unless it is in a gross state of disrepair or tune.