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Super Six conversion running rich
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Author:  64 Convert [ Tue Apr 04, 2006 1:44 pm ]
Post subject:  Super Six conversion running rich
Ever since I put the Super Six setup from a '79 Aspen on my '64 Valiant, it's been running a little bit rich and the carb is perking when the weather gets warm. I rebuilt the stock BBD carb when I installed it and driveability and performance is great compared to the 1bbl Holley, but mileage is off somewhat and at the current price of gas, I'd like to address that problem.

Because of our hot summers in Texas, I set the float on the low side to minimize the perking problem that exists with virtually every carbureted car, but it hasn't helped much. I'm thinking of adding another insulating spacer under the carb, which should help that. Any other suggestions?

In my experience, when a carb wears, it usually tends to run lean, not rich. Has anyone else experienced a rich condition when installing an emissions jetted carb on a non-emissions engine?...or do you think I have an isolated case that simply needs some custom tuning?
Author:  SlantSixDan [ Tue Apr 04, 2006 3:18 pm ]
Post subject:  Re: Super Six conversion running rich
Quote:
Because of our hot summers in Texas, I set the float on the low side to minimize the perking problem that exists with virtually every carbureted car, but it hasn't helped much. I'm thinking of adding another insulating spacer under the carb, which should help that. Any other suggestions?
Fuel line mod
Quote:
In my experience, when a carb wears, it usually tends to run lean, not rich.
Both are equally possible.

Your carb probably needs closer attention.
Author:  Reed [ Tue Apr 04, 2006 7:00 pm ]
Post subject: 
As Dan said, do the fuel line mod. Then go back and reset the carb to the factory specs. WHile you are in there, be sure to set the metering rodfs properly.

The factory carb from a 79 Aspen should be plenty lean already. If you are having problems due to heat I recommend you switch to a bigger radiator, install a fan shroud, install a 7 bladed fan or install an electric fan, and as a last resort install a carb heat shield.

Also of high importance is the choke pulloff assembly. Did you install the factory SUper Six choke pulloff coil? Did you also install the electronic choke pulloff assist? If not, your choke will stay on too long and hurt both performance and mileage. I just installed a factory Super Six setup on my van and the choke comes off high(est) idle within 30 seconds of starting the car cold in the morning.
Author:  SlantSixDan [ Tue Apr 04, 2006 7:07 pm ]
Post subject: 
Quote:
Also of high importance is the choke pulloff assembly. Did you install the factory SUper Six choke pulloff coil?
Choke pulloff coil...? *baffle*

The choke pull-off is a vacuum pot that's not the same part as the choke thermostat (which does, on the super six engines, contain both a coiled bimetallic spring and an electric heater coil).
Quote:
I just installed a factory Super Six setup on my van and the choke comes off high(est) idle within 30 seconds of starting the car cold in the morning.
Sounds like you've got it all set up correctly!
Author:  64 Convert [ Tue Apr 04, 2006 8:23 pm ]
Post subject: 
The car doesn't overheat, the carb perks only after it's been shut off for a while and then it floods when re-starting. It does not vapor lock, or perk when the engine is running. I had the carb load-up problem with the old 1bbl Holley, but this one hasn't had that problem.

FWIW, I'd love to put an electric fan on it, but there is no room...at least I haven't found a thin enough model yet and since it has A/C, I can't put it in front of the radiator.

The Super Six setup is stock, without the electric assisted pull-off. The choke is a brand new Echlin that went on with the two barrel and hasn't given any starting problems at all.

It doesn't run too rich with a cold engine and it's only slightly rich when warm and the choke is fully open. I've checked and I don't have a hanging choke, so the over-rich condition must be from the jets and metering rod combination. Since the setup came from a totally stock 4-door that belonged to an old lady since new, I doubt the jetting has been changed.

All the carb settings are for per the kit specs and the only change I made was to set the float at the lowest level. That's pretty much the standard practice here where the temps are over 100F much of the summer. I've done that to both my 4bbl V8 cars and the perking problems went away.

The car starts well when it's cold, has excellent throttle response and driveability. It just smells a little rich and now and then I see a wisp of black smoke from the exhaust. The inside of the tailpipe has a black velvet look that is not oily and the engine doesn't burn any oil, so I'm pretty sure it's unburned fuel. Since it has a new Mopar electronic ignition, new plugs, new coil, new ignition wires and a new air filter, I'm not looking at that as a cause for incomplete ignition.

Does anyone know a source for a new Carter carb? The only thing I can find locally are refurbs. I'd just as soon buy a new one as fiddle with an old one or take my chances with a refurb. By the time I sent this one in to a specialist for repairs and tuning, it would probably cost nearly as much as a new carb.
Author:  Reed [ Tue Apr 04, 2006 8:57 pm ]
Post subject: 
Quote:
Quote:
Also of high importance is the choke pulloff assembly. Did you install the factory SUper Six choke pulloff coil?
Choke pulloff coil...? *baffle*

The choke pull-off is a vacuum pot that's not the same part as the choke thermostat (which does, on the super six engines, contain both a coiled bimetallic spring and an electric heater coil).
Quote:
I just installed a factory Super Six setup on my van and the choke comes off high(est) idle within 30 seconds of starting the car cold in the morning.
Sounds like you've got it all set up correctly!
All right, if you want to get really picky, yes the vacuum choke pulloff is a system incorporating a vacuum port on the back of the carb and a diaphragm which pulls the choke open roughly 1/8 of an inch as soon as the engine starts to run and vacuum is created. I was also referring to the bi-metallic choke pulloff spring and rod which goes on the pocket on the exhaust manifold. On a 64 car it is heated only by exhaust, but on later cars it got electric assist. When I said "choke pulloff coil" I meant the bi-metallic spring.

64 convert- you should install the electric assist. The bimetallic spring is designed to have it and you are burning extra gas needlessly by having your choke stay on too long. What are your curb idle screws set at? I recommend you work with this carb rather than risk buyiong a remanufactured one.
Author:  SlantSixDan [ Tue Apr 04, 2006 9:32 pm ]
Post subject: 
Quote:
The car doesn't overheat, the carb perks only after it's been shut off for a while and then it floods when re-starting.
Go ahead and do the fuel line mod.
Quote:
The Super Six setup is stock, without the electric assist
Do as Reed says; hook up the electric choke heater. That's what the wire is for that's coming off your new Echlin choke thermostat. You'll also need the choke heater modulator—best to get a new one; Echlin has them in their line.
Quote:
The inside of the tailpipe
Judging fuel mixture by the tailpipe appearance went away when leaded gas went away. It will always be black with unleaded, whether running rich, lean or just right.
Quote:
Does anyone know a source for a new Carter carb?
They show up occasionally on eBay, or you can spend $$$ from a few sources I know of...are you really up for a $300 carb?
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