Mopar 440 ideas?

[Hersbird]

Originally Posted by 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.

The air pump was more of a bandaid to pass emission tests by just adding clean outside air into the exhaust pipe diluting the pollution so it met the sniffer test. It didn't really improve emissions at all, in fact it hurt them because it required horsepower to drive the pump. A silly loophole.

I suppose this is not true for every motor out there, but I suspect this was Dodge's reason they used them.

[gone-ot]

OOPS! I guess I was remembering 2.93 (correct) vice 2.73 (wrong) ratio. But, I can say that my 1970½ 340/6BBL engine did NOT have an airpump, so I'm guessing maybe the airpump was only used on California cars.

[Cd]

Pictures please !

( I'd love to see some of yours as well Tele )

[freebeard]

Does it have to look stock on the outside?

A Superbird nose and a plexiglass cover over that back window tunnel would gain a few mpg, whatever else you do. Forget the coat-hanger spoiler.


http://www.rollyrocker.com/roadrunnersuperbeemain.htm

1970 Plymouth Superbird

• 1970 Mopar technology
• drag coefficient better than many 1990s cars (.28)
• capable of speeds over 150 mph, stock! (max. 180 or so)
• considered ugly at the time and a poor seller
• standard 440 and optional 426 Hemi.

A bellypan, wheel spats and a diverter would help and they're all underneath.

[jcp123]

Your later 70s Chrysler lean burn setups were fairly effective, if memory serves. I'm away from home but there were articles of 70s Imperials easily besting biggies from Lincoln and Cadillac when so equipped, and that was sans overdrive or any kind of lockup. IIRC they were quoting mileage in the 17mpg range on the open road, bone stock in those 5000lb biggies.

[oil pan 4]

There are guys that have old GM 60s and 70s cars with big blocks and up dated drive line using over drive autos and better highway gears (3.30 to 3.55) are getting 15 to 18.

Originally Posted by 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.

GM stayed with a V8 and made it bigger.
They went from the 7.4L to the 8.1.


I say try using a carb and tune it with a wide band oxygen meter.
Tune the primaries to run a little lean and run the secondaries as fuel dumps bring the A/F ratio down to between 12.5:1 to 13.2:1.
If you are going to drive cross country you don't want a bunch of proprietary fuel injection system parts that cant be found at any auto parts store.