white smoke after carb rebuild - ?

[Dal Bone]

So I just finished rebuilding my center carb on my 440 six pack. After starting it up it is putting out a large amount of white smoke out of the tail pipes. I have the idle mixture screws set at 1 1/2 turn CCW out.

Could the float level be causing a large amount of white smoke? Possible vacuum leak?

Any thoughts on where I should start to identify the problem?

[Chryco Psycho]

well white smoke is usually a water issue
 blue is oil &
black is fuel
So how does it run ?
 Is the intake tight ?

[HP_Cuda]

Hopefully it's not a head gasket issue. Any work on the intake lately as Cryco said?

[Chryco Psycho]

every spring & every car I tune up my first step is to tighten all of the intake bolts first .

[mopar jack]

If it was fine before the rebuild and just started smoking after I would suspect too much fuel. The rebuild kit should have included new needle and seat so the floats will have to be adjusted. Make sure the metering block is seated properly and the bowl screws are tight as this can cause fuel to leak into the intake. If that doesn't solve it I would pull the bowl and metering block and check that the power valve gasket is correct and centered.

[cudabob496]

I got white smoke once when I was having trouble
starting my 440 with a 850 double pumper.
Engine was cold, and I may not have been giving
the engine enough gas at starting. Or intake was
too cold at the time.

[Dal Bone]

Thanks for the suggestions so far.

-Yes it was fine before I pulled the center carb so there is a strong possibility that the carb is the source of the problem.

-The kit did come with a new needle and seat but it was a smaller length than the original one and did not have the screw on top to adjust the float so I re-used the old one. Do I need to merge the old needle and seat upper portion with the new one from the kit? I didn't think the float level would cause this problem but I guess I could be wrong.

-I did not do any work on the intake. Just pulled the carbs. With that being said I was able to tighten them all down about a 1/4 turn so they must have loosened up.

After work I will go out and adjust the float to see if that helps the situation. 

[Dal Bone]

Update -

So I tightened the intake bolts and lowered the center carb float level until it was slightly running out after the sight plug was removed. Seemed to reduce the white smoke initially but returned quickly after driving it around the block. It smells pretty rich.

I guess at this point I can lean out the idle mixture screws a bit?

Also I seem to lose some brake power at lower RPM. I am thinking I might have a vacuum leak somewhere as well...

[Chryco Psycho]

DId you match the gaskets exactly when you rebuilt the carb ?

[HP_Cuda]

Ok when you rebuilt the carb did you change the internal jetting/power valves? Is this a Holley?

[Dal Bone]

Sorry for the late reply. I have been busy as you will see. So I knew that in order to properly tune the car after the carb rebuild I needed to ensure there were no vacuum leaks. Even after tightening the bolts on the intake manifold I was not confident that it had a good seal. I pulled off the intake, removed the valley pan and cleaned the heads and rails to remove the old gaskets. I installed a set of gaskets between the heads and a new valley pan. I used Hylomar gasket dressing on each side of the gaskets, rails and between the valley pan and intake manifold. I found the proper torque sequence from Edelbrock and torqued it to 25 ft/lbs.

After putting everything back together I set the timing and adjusted the idle. No more smoke and it idles really well!

It still smells a little rich so I put a vacuum gauge on it and it only reads about 8 Hg of vacuum and the needle was a little jumpy. so I still have a vacuum leak somewhere but I have no idea where.

Ok when you rebuilt the carb did you change the internal jetting/power valves? Is this a Holley?

Yes it is a Holley six pack setup. No i kept the internal jetting the same. Both jets are 62. The rebuild kit came with a brand new power valve which was 6.5. I believe I should be at LEAST 15 Hg vacuum with this power valve. With such low vacuum am I accurate to assume that this is why I seem to be running rich?

[734406pk]

Check your ignition base timing. Do you know what camshaft is installed in this engine?

[Chryco Psycho]

SO why do you think you have a vacuum leak ?
8" of vacuum may be all it will make , smell is nothing , if the engine is loping & it should with only 8" vacuum there is unburned fuel coming through ,so yes it will smell rich  what do the plugs look like or get an AFR to tune with . I would change the PV to a 4.5 " or a 3.5 if it is an automatic trans  with the low vacuum . I also agree that you will need 12* & probably more towards 16* initial timing  & this may help your vacuum reading .