Carter BBD on my slant, help with float

[gdizzle]

So on my 66 dart slant, I swapped it to the Super Six along with the Carter BBD, the correct one with the holes in the flaps.
Anyhow I continue to have super low MPG, like 10 mpg if that. And lots of carbon on the tail pipe and spark plugs.
I have adjusted it several times, and tried to lean it out as much as possible. I get 21inches vacuum off the intake manifold.
I also have advanced the timing at to about 18. no knocks.

I am thinking that the float may need adjustment, I rebuilt the carb last year and I can't find that little cardboard measuring thing. I watched the old Chrysler video on this carb and they show being able to adjust the float while it is on the car, but they use some sort of measuring stick that I would like to replicate. Any ideas? hep me out. thanks FABO

 

[mvh]

I'm looking at the Carter BBD manual, and the float adjustment for almost all applications is 1/4". The standard adjustment procedure involves flipping the carb upside down. But I can see how you could do it on the car, by holding it with your finger.

 

[gdizzle]

I'm looking at the Carter BBD manual, and the float adjustment for almost all applications is 1/4". The standard adjustment procedure involves flipping the carb upside down. But I can see how you could do it on the car, by holding it with your finger.

yea in the old video , the guy pushes it down with finger, then measures. Gas is in there as well, so his fingers get gas on them. So what would be a good tool that I can set a 1/4 stop on and then rest it over the entire assembly? in video he is using what looks like a T square with some adjuster on the side??

 

[mvh]

Could be anything.... just mark 1/16" intervals on a matchstick or a strip of cardboard. I don't recall needing a right angle reference.

 

[Slantsix64]

Does it have a new timing chain? check for slack. Trying to achieve good gas mileage with a loose chain is impossible.

 

[AJ/FormS]

Hang on
The upside down dry method is different that the wet method with fuel pressure applied.The dry method of 1/4 inch might be 3/16 or 7/32 IDK, when running, and that might be normal.

But hang on some more, I wonder if float level is your problem at all. I mean that car should be getting 15mpgUS or more. If you are getting only 10 than you have much more serious issues.

If it was mine,I'd start with the basics; verify the choke is coming off,fast, and that the float-valve is not leaking.
Then verify the TDC mark, adjust the valves,and do a compression test.
Then verify the minimum engine operating temp is correct, for your area.
Then verify that the MJs are correct for your altitude.
Then verify that your ignition system has some balls.
Then verify that the power valve is working right, that the PCV is correctly plumbed,that the T-Port sync is close,that the accelerator pump is correctly adjusted, and that all the timing mechanisms are correctly working.
Then mess with the float level.
That's what I would do.

 

[gdizzle]

Thanks for all the ideas. I had this engine rebuilt 2 years ago, new everything, new chain etc... This car mostly sees city driving, very little freeway. The temp usually gets to around 190. I have converted it to HEI. It runs real good, never stalls, starts right up. I was just hoping for a little more MPGs. but I do know it it running rich based on amount of soot and carbon on the plugs. it is also a little gassy smelling, though no visible leaks. most of the ports on the carb are capped off. I am just using the ones that my engine needs.

 

[AJ/FormS]

You know it's running rich;
But on what circuit? and why?
Maybe the choke is staying on too long, or the float valve is not shutting the fuel off.
Maybe the TDC mark has slipped and the timing isn't what you think.
Maybe the intake valve lash is too tight, and the piston is driving some of the mixture back up into the intake, and the next cylinder in the firing order gets too much fuel.
Maybe the MJs are too big for your altitude.
Maybe your ignition coil is weak, and the engine suffers from misfires.Maybe the plugs are the wrong heatrange or the gaps too small.
Maybe the spring under the PV is weak or of the wrong calibration, and the darn things are not staying down, or it is out of proper adjustment.
Maybe the timing is too advanced and the T-Port sync is way off so you cranked out the mixture screws to keep it idling. Then as soon as the throttles tip in, everything goes rich.
Maybe the accelerator pump is set really rich and everytime you move the gas pedal.POW! the pump unloads.
Maybe the timing curve is too slow or maybe it is too fast, or the V-can is lazy or busted, all could lead to low efficiency, and the throttle having to be too far open to move the vehicle.
Maybe a cylinder went down, and you spend 14 hours chasing ghosts when it really would have been caught on a compression test.
Maybe AJ's out to lunch, and it just needs to have the float level adjusted.
Maybe the earth really is flat, and the sun is not nearly as far away as those stinking lying scumbag scientists of the last century said it was.
Question everything.

 

[Slantsix64]

You know it's running rich;
But on what circuit? and why?
Maybe the choke is staying on too long, or the float valve is not shutting the fuel off.
Maybe the TDC mark has slipped and the timing isn't what you think.
Maybe the intake valve lash is too tight, and the piston is driving some of the mixture back up into the intake, and the next cylinder in the firing order gets too much fuel.
Maybe the MJs are too big for your altitude.
Maybe your ignition coil is weak, and the engine suffers from misfires.Maybe the plugs are the wrong heatrange or the gaps too small.
Maybe the spring under the PV is weak or of the wrong calibration, and the darn things are not staying down, or it is out of proper adjustment.
Maybe the timing is too advanced and the T-Port sync is way off so you cranked out the mixture screws to keep it idling. Then as soon as the throttles tip in, everything goes rich.
Maybe the accelerator pump is set really rich and everytime you move the gas pedal.POW! the pump unloads.
Maybe the timing curve is too slow or maybe it is too fast, or the V-can is lazy or busted, all could lead to low efficiency, and the throttle having to be too far open to move the vehicle.
Maybe a cylinder went down, and you spend 14 hours chasing ghosts when it really would have been caught on a compression test.
Maybe AJ's out to lunch, and it just needs to have the float level adjusted.
Maybe the earth really is flat, and the sun is not nearly as far away as those stinking lying scumbag scientists of the last century said it was.
Question everything.

Hahahaha