1970 Dodge Charger 440 4bll carburetor questions

[RJRENTON]

Thank you Bob - good stuff. How can you tell it is an Eddy or you just know? My mechanic thought it was a Carter probably because he thought it was original.

I was able to contact the second owner of the car and he said that in all the back in the late 80s, he had the original 318 engine 2 bbl swapped with a "1973 440 donor engine" and also they put on a new carburator on it at that time. So don't have any original carbs. The second owner also told me that he later had it converted to electronic ignition. The choke is electric too.

As far as the potential valve issue, the mechanic told me twice he removed the valve cover and didn't notice anything unusual. My brother told me though the only way to know for sure if to have the head removed and to test the springs.

As far as the carb hoses, it looks there there are two places

I plan on taking it to a Speed Shop on Wednesday for evaluation and convey all the ignition recommendations from this forum in additon to any finding regarding the carb hoses and anything else.

I could also look into the speed shop putting in an original Carter?

As far as the operation of the valve train, the easyist to operate the engine with the valve cover removed....it sounds as if an exhaust valve is not opening fully, due to a worn lobe or a bad rocker arm....they have been known to fail where the push rod socket pushes thru the rocker arm. If a valve seat or valve is damaged, a compression test will disclose the problem.
The Edelbrock carb is an aftermarket replacement for the original Carter AVS. its similar in appearance to the original Carter. Edelbrock bought the license from Carter when they went out of business. The aftermarket unit resembles the original but metering calibration is different; metering components are similar and some parts (jets and metering rods) can interchange. The Edelbrock part number is stamped on the mounting flange near the mounting bolt, behind the coil or on a stamped tag under one of the air horn screws. Research this number with Edelbrock to determine the CFM of your carb along with the metering rods and jets that were supplied compared to what is actually in the carb.
Someone installed an aftermarket electronic ignition conversion depending on who supplied the components, the control box (ECU) have been known to have intermittent issues and can fail without notice. Test and record the compression of each cylinder using the factory shop manual procedures. Its not likely that a head gasket has failed but possible...the shop manual explains.
Almost everyone over carburates (bigger than needed) in search of more power which results in poor performance. Its too bad that the original carb is MIA.... Again, just my opinion....
BOB RENTON

 

[Geoff 2]

Have not read all 5 pages, but:
- find a new mechanic. Somebody who knows what he is talking about because.....
- Carter 4 bbl carbs are the most reliable, consistent carbs you can get. Easy to work on & tune.
- Exh b/firing on one side is unlikely to be carb related. Could be worn cam/lifters, severe vacuum leak, plug wires or or dist cap, ign problem.

 

[Geoff 2]

Just a comment on Carter/440 cfm ratings.
Carter did publish cfm ratings for some carbs. I have two Carter catalogs that show the cfm ratings:
- the small primary TQ is rated at 800 cfm
- large pri TQ 850 cfm
- the AFB with small pri & large sec is listed as 625 cfm
- the AVS with small primaries [ 440 low perf ] are rated at 630 cfm
- the AFB with the same size pri & sec throttle bores [ 1 11/16" ] are listed at 750 cfm.
- the AVS with large pri & sec bores as used on the 440 Magnum would be 750+ cfm based on the above info.

Earlier AFBs that had the same size bores & venturiis as above had lower cfm ratings because the smaller air horn diameter restricted flow.

 

[BSB67]

Interesting thread. I’m going to be brutally honest here. If a guy that doesn’t seem to know much of anything about his muscle car and doesn’t want to do the simple work himself and is using a mechanic that doesn’t seem too good either, it will be painful exercise

If you have a bunch of disposable income, find a better mechanic and start writing checks,

Or

Bring the car home and start learning and working on it yourself,

Or

Maybe muscle cars is not a good hobby for you.

Good luck

 

[Bee1971]

1287 9G36S4 ( this is the best I can see / tell from blowing up the picture)

Carter AFB 9635 S - 9636 S - 9637 S

625 CFM

Emissions + EGR Hookup are unique with the Bowl Vent and EGR Hookup

9635 S - GM Linkage
9636 S - MOPAR Linkage
9637 S - Ford Linkage

 

[A4GTX]

If new ignition wires doesn’t fix it, RUN A CYLINDER LEAKAGE TEST.

 

[SlinktRR]

Agree with BSB. Over time you have to develop a network that can help when you can't do the work yourself. Every year this number gets fewer and fewer as the mechanics who know these cars retire. So you are then forced to rely on restoration shops which have varying skill, long turnaround time and high prices. At some point you will be forced to learn to get the most out of owning these cars. Like most things it just takes time and interest. Between a service manual, YouTube and forums it has never been easier to get the info you need but the trick is piecing it all together.

I would park it in the garage and take the time to troubleshoot, simple stuff first like plugs and ignition for the misfire/popping then work your way through learning the ways of the Carter Edelbrock carbs.

 

[OKDart]

If it’s getting worse, sounds like a wiped out cam, which is common these days using regular oil. How many miles is on the rebuilt engine?

Since you don’t have time to work on the car yourself, I would go to some local car shows and talk to the Mopar guys. They can recommend someone to work on your car better than anyone.

 

[72RoadrunnerGTX]

1967 -1970 440 low performance (read C-body engines only) came with Holley’s. Really one of the worst Holley’s ever.

440 magnum never had a Holley

With one model year exception, nothing but Holley 4160s on 1972 440 HPs.

 

[R413]

With one model year exception, nothing but Holley 4160s on 1972 440 HPs.

If you would quote my full post #12 I mention the years 1967-1971.

I don’t include 1972 and newer and 440 magnum together. don’t know what they had in 1972, they ruined the cars. IMO.

 

[72RoadrunnerGTX]

Nothing to disagree with in the first sentence of that post about low performance 440 OE Holley’s, including the reference to low quality, didn't see a reason to quote it. Only taking issue with the comment about 440 HPs never having run Holley OE carbs, no specific to model year range qualification. Your opinion aside, 440 HP’s, or Magnums, were produced thru ’74 and in one model year only they came OE Holley 4160s exclusively.

 

[matchek]

By the way, some folks mentioned the carb did not have hoses attached and/or attached properly. Does anyone know where these hose go or has a pic of their car with hoses attached?

 

[RayHemi]

Carter is a fine carb. So is Holley. Does it happen before or after warm up? What intake do you run?
Read SlinktRR again. I'm a mechanic, so I have tools. But your most important tool at this time is the FSM.
Make print outs or copies and use a highlighter - keep notes and log readings. Double check your procedures, fit ups and so on. This lets you know what it's not.
Keep an eye out for witness marks that indicate previous work in suspected areas (this rarely means the person before you fouled something up like for example a short cut that's rough but works, but sometimes you see things you need to get into.) Get sets of gaskets for this - or - that then take your time, you can always return the gaskets. Many places will rent you the gauges. Sounds like your mechanic is close. After you get more reference material (specs and procedures), including from here, report your progress to him/her. You obviously have dual exhaust with no cross pipe, right? Oops, scratch the question, I hadn't looked at all the photos.

 

[Orig69]

Do you have pictures of the area around the back of the carburetor?

 

[matchek]

The backfire happens when cold and warm. And the backfire only happens when you hit the pedel modeeratley hard or above. It does not seem to backfire at idle or gentle driving.

 

[matchek]

Dumb questions, but can diagnosing the car make the engine performance worse? From my understanding, the mechanic did a compression test, adjust the carbs and timing. From what I know. Can a compression testing/cylinder leakage test damage a seal somewhere where it presently did not exist? At this point my first objective is to get it running as it was before, which was fine except a backfire at hard pedal where now it runs awful. I hear about the replacing the electrical components. The reason why I ask is it ran fine before I took it to him before his diagnosis (except for back fire at hard pedal which I did not observe because I did not give it really hard pedal).

 

[Kern Dog]

In extremely rare instances, a car can run just fine and just decide to crap out without warning. As any FORD owner.

Seriously though...
It can happen.
A compression test means pulling all the spark plugs and removing them. Maybe the guy crossed the # 5 and 7 plug wires when reinstalling them? That would make it run rough. 5 and 7 fire one after the other. 18436572. If 7 fires before 5, it is early. If 5 fires after 7, it is late. Both cylinders firing out of order means you've lost 25% of your power.
Maybe a vacuum line has a crack or hole in it that isn't visible. One picture showed a 3/8" vacuum nipple with no hose on it but I suspect that was a bowl vent. A missing manifold vacuum line will result in a rough idle and poor performance.
The electronic distributors have a very specific adjustment of .008" for the air gap. Often times, that can slip and widen. I've had mine move out to .020 and while the car still ran, it popped and stumbled under a load.
If he replaced the plugs, sometimes even new spark plugs fail.

 

[pnora]

I have to ask about this backfire as I can read your story 2 ways. Is the backfire out of the intake manifold or exhaust?

 

[WileE]

First things that any competent mechanic (you don't have one ) will do is compression, leakdown, and vacuum gauge tests. When that's done, come back and tell us. Shooting arrows all over the place gets you nowhere.

 

[Orig69]

Maybe it's just me but the vacuum hose for the brake booster looks like it's not hooked up to anything.