1970 Dodge Charger 440 4bll carburetor questions

[Bee1971]

From my understanding, the 1970s 440 came with Carters. If it worked I would not mind putting on a brande new Holley and saving the carb original car.

I need to know what the original CFM was on the original Carter Carb.

I told you in post # 7

 

[matchek]

When you give it hard gas there is a loud cracking noise coming from the driving side exhaust. I have cherry bombs in the exhaust so I thought it was just that, but the mechanic said that really loud cracking noise is backfiring. He also pointed to the engine shaking a little bit more than normal. Also he drove it and said the power is not to the point a 440 should have. He said when you punch it, you should easily spin the wheels.

 

[matchek]

Okay, thanks Bee, when you said someone would argue with the numbers, I thought that mean you did not know.

 

[matchek]

By the way, Bee, would you please post a pic of the Carter Manual?

 

[pnora]

When you give it hard gas there is a loud cracking noise coming from the driving side exhaust. I have cherry bombs in the exhaust so I thought it was just that, but the mechanic said that really loud cracking noise is backfiring. He also pointed to the engine shaking a little bit more than normal. Also he drove it and said the power is not to the point a 440 should have. He said when you punch it, you should easily spin the wheels.

You need to get better diagnostics. Could have internal engine problems. Start with a simple compression test. Backfire and rough idle does not point to a carburater to me. I seriously doubt buying a new carburetor is going to fix it.

 

[eldubb440]

mechanic can't tame a carter? and wants to replace with a holley? ....... hmmmmmm

 

[matchek]

The mechanic spent two hours already looking at potential vacuum leaks, compression test, spark plugs, timing, carb adjustments, pulled valve cover gaskets, etc. All look good to him. He did say that the he is used to brighter color on the spark plug wires or something, but looks good.

 

[RemCharger]

440 magnums came with at least 750, nothing less. 600 holley bad idea.
A carb doesn't necessarily use "more gas" the bigger you go. It has more air cfm potential.
The 3310 would work great as thousands, no, tens of thousands of other people have previously used in the same combo.
I put one on my Dad's stock magnum and it performed FLAWLESSLY on many long trips and times to the track.
Nothing wrong with a stock Carter too.


It sounds like you need a fresh set of NGK XR5's first though. ( spark plugs)

 

[sam dupont]

I was trying to be respectful towards your mechanic... and Holley, but off come the gloves.

It's good to know our shortcomings, but to inflict a non-original Holley on a customer because you suck at carbs, gives the mechanic trade a bad name. Holley won't tell you not to dick up your car, they're gonna sell you a carb; it's what they do.

I know a Holley 750 is fine, but it's also $450 before a wrench is turned. I'm guessing a rebuild of your original carb is nearly half that number, and everything fits. With the Carter, there will be no gas lines or throttle cables cobbled together and made to work, or the fabrication costs to do it. If he can't rebuild a carb, how is he to retrofit a Holley carb? It's an installation that may stick WOT on you one day as you're playing with your car. That is something that's happened to everybody here.

A friend of my dad's had a new 70 Mopar with a 440. He let me take parts off of it after he was turning right at a stop sign, spun the tires a little bit, and he said the next thing he knew he was overturned and sliding down the railroad tracks on the roof. Will Holley promise you they can top that kind of performance?

 

[matchek]

Appreciate the input . Makes sense.

Speaking to the Holley rep, the old CFM ratings were sometimes inflated compared to know and now they determine CFM needs based on engine size , efficiency, and max rpm I would drive. Assuming a Mac rpm he calculated 585 CFM. He said the 750 would run better at real high rpms but not as good tooling around town.

 

[4speed68rt]

Luck shouldn't be a factor in working on a car. Science is a better method. Have the carter rebuilt, or do it yourself, its not that difficult. Holley is not going to make anything any better. Nothing against a Holley, I have several, but for "tooling" around town, stick with what the Chrysler engineers decided. There is a reason they didn't pick a Holley. You will always be fidgeting with a Holley, for everyday driving.

 

[matchek]

If I was to have it refurbished, is there anyone you recommend to send it to? One of the reasons the mechanic suggested a new one is that he had troubles with Carters for years and did not want me to disappointed after the rebuilt. I hear you though. Sounds like there should not be anything wrong with the Carter. Unfortuneatlely I bought it with the backfire so I don't know what caused it in the first place.

 

[matchek]

Also dumb question, if I was to have it sent it out to be refurbished, what do they do and how much you think it would be? The Carter does looks like a nice carb.

 

[AR67GTX]

Popping and mild backfire in the exhaust is often due to an exhaust leak - exhaust manifold leak, rotted out heat riser mechanism on the right or bad joint to exhaust pipe. I currently have a 50/50 mix of Carters and Holleys on my old cars. Holleys are fine, make great power, but take regular attention and develop leaks from time to time. The blue, reusable gaskets were a great step forward in maintaining a Holley but now they use those stupid plastic bowl screw gaskets that won’t seal after use for awhile and you have to go hunt for the old fiber gasket type seals. Bowls and metering plates warp. Once a Carter is dialed in, feed it good clean fuel and it just runs. Not as flexible in some aspects of tuning as Holley but most of us are probably better off not fooling with them too much anyway unless an O2 sensor is installed. My 2 cents.

 

[matchek]

Thanks AR67. I thought he said the manifold sounded good and didn't have leaks but I can let him know again. Not sure if it helps but there is not cracking noise under the hood. Not sure if that helps. The reason why I mention is I have a 68 Oldsmobile that has a warped exhaust manifold and it was loud upfront and needed it replaced. It did not backfire, but it was noisy and I can smell emissions when I drove it.

By the way, I should mention that when I bought it 1.5 years ago , the backfire sound was there then and a lot of the parts looks newish meaning less than 5 years old on little wear so doubt it anything it rotted, but could be installed imperfectly.

 

[matchek]

I also need to mention that he said the engine shakes a little (I saw it , not that bad but he likes it still) and said that when he drove it didn't feel like a 440 and should spin the wheels easily. This is in addition to the drivers side backfire so why he was thinking the carb.

But by the way, he said the plug looks fouled so I could probably use plugs and he did not rule out the coil. He said the car had electric choke and electronic ignition if I remember

 

[pnora]

My bet is a good mechanic should be able to diagnose within 2 hours. I would try to locate a sharp Mopar guy in your area. Find a local club and ask.

 

[pnora]

Post some pics of your engine and carb.

 

[F4R/T]

One must remember that carter also rated CFM differently than Holley. A AVS carb is a very very good carb and simple to maintain. I’d call @Woodruff Carbs for some help, the backfire issue out one side sounds odd and I’d be dialing in my timing and checking for a valve issue not sealing at worst. Too many variables here imo. I love my Carter’s...also do you have a factory h pipe or two single pipes for your exhaust ?

 

[Rebelrouser]

I agree find a better mechanic. On a stock application the Carter if right, will run just as good and get better mileage than the Holley. On a race engine the Holley would run better, but you have to buy a good Holley, not a vacuum secondary cheap one. If it is backfiring out one side of the exhaust you have a bad plug wire, broken valve spring, or worst case a flat lobe on your camshaft. Put a vacuum gauge on it at idle if the needle is jumping around, it has a valvetrain issue for sure.