VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc All new but black smoke issue

This update is prompted by ChevGene's inquiry on Brewster's string about the Central Meet in Ontario.

YES, the '56 wagon is still belching black smoke!!!

We very successfully drove 1,142 miles to the Meet and back, and it ran very well the entire trip. Mostly Interstate travel, at typically about 60 mph (or 100 kph depending on the country!). It ran as good as any car with a recently completely rebuilt drive line would be expected - that is to say, very well indeed. If it wasn't for my rear view mirror, and people that follow me running up to tell me it makes black smoke every time we park - I would never know there was any problem at all. After methodically converting litres to gallons and doing all the arithmetic, we averaged 15.5 mpg for the entire trip. Good enough.

A few evenings, we raised the hood and many knowledgeable guys looked everything over, and we ran through the litany of things that have been checked over and over, and made no progress. Studied the Shop Manual and Service News Bulletins, etc. Checked the timing with a light, checked that the vacuum advance was working.

I am completely at a loss. I even pulled the innards out of the air cleaner and ran a few hundred miles with just the outer housing on, to make sure I didn't have some mysterious obstruction in there that starved it for air flow. But it was the same.

I'm down to thinking I need to re-re-re-check the accelerator pump, and possibly start thinking about the ignition system, maybe I'm not getting adequate spark to completely burn the charge.

It's extremely frustrating. Two completely, meticulously rebuilt Rochester 4 BBLs, and yet the same problem with either - makes you think it's maybe not a carb problem. Many other 4 BBL 265's are running around and NOT making black smoke on acceleration.....

Not familiar with '56 wagons but is there a rubber connection in between the air cleaner and carb?

I once got a very good deal buying a car the had similar 'uncurable' problems, it turned out to be the rubber hose delaminating, it was collapsing inwards and restricting the airflow when running but looked quite normal off the motor.

Bernard

No rubber - steel air cleaner sits directly on top of the carb, like any V8 of the era. Wagon's engine compartment is identical to any other body style or model.

Too bad that you do not live near me..... I would let you try my 1957 Carter as a a test.
For driving only 60 MPH I would call that about 2 MPG lower than it should be.