Title explains it - black soot coating the garage and driveway - only on startup. I've read threads in other places - most that it's "running rich" or "this is normal" - but we had a 50 and this 51 growing up - never had the issue with the 50. And it's just .. a lot. The car runs a bit rough when cold, but when it warms, it's perfect. My high level question: If this is the same muffler/exhaust that's been on the car for 20+ years - is it possible it's just lined with soot and replacing would rectify? I have zero issues once this car is warm - but the mess at startup bugs me. Thanks.
Too much choke? Stuck vacumm power piston in carburetor. Vacumm to power piston shut off due to insulator block problem. Somewhat normal for several reasons - my 1950 does it too along with black water.
If you only drive the car on short trips (less than 10 miles) without heavy acceleration or extended runs at higher speeds I expect that there could be a build up of soot/carbon in the exhaust system.
I have used the “water” trick to clean surface carbon and soot out of an engine. It is a trick I learned from my father.
Drive the car quite a bit to get everything up to a normal operation temperature.
Remove the air cleaner and start the car. Slowly pour a small stream of water into the carburetor. You will need to keep opening the throttle so the engine keeps running. It will stumble some and miss but keep it running. Back off on pouring the water and let the engine come up to speed. You do not want to stall the engine. Then keep doing this for about a quart of water. You should see steam coming out the tailpipe.
Some people have done a similar treatment with products like Seafoam, Marvel Mystery Oil, and Gumout.
If your driving consists of mostly low speed driving, even when it runs perfect, it is possible to accumulate some soot in the tail pipe. Starting will cause so water condensation in the exhaust, and the water will wash some of the soot from the tailpipe, staining the driveway.
Easy solution: place a shallow pan under where the water drips for start-up.
Thanks for the thoughts - what about this? A guy who works on vintage cars of similar year - suggested that I find the lowest part of the muffler and drill a very small (smallest) hole in that part of the muffler. He said that if condensation builds, as it will, this may help allow it to drain. He claimed that Midas mufflers used to have a small hole in them for this reason (long time ago).
Over the years I have had mufflers that have a drain hole. While it does let moisture out of the system it is also the place where the muffler starts to rust.
This has nothing to do with the soot/carbon issue.
The best cure for both issues is avoid driving only short trips.
Ok - I thought I'd add a picture here to show how much I'm talking about - the pic attached is from ONE short run (2 min) in my driveway. One.
Yes, this car has been - for years - a "short trip" car - every few weeks. No tours. I asked my father if he'd every changed the muffler (he bought the car in 1974) and he said no - never did. Is it ridiculous to think that - mufflers weren't made to be used for 45 years - and maybe this one is caked with soot?
Nothing in that picture surprises me for a short trip car. Replacing the full exhaust system will only solve the problem for a while. It will eventually cake up again if all you do is short trips.
Thanks, Rusty - appreciate all your comments/help. Does anyone ever put a more 'modern' muffler on one of these? I recognize that would impact judging, etc. - just curious.
That looks a lot like the amount of soot on startup with my ‘50 Fleetline and stock 216. It too is a short drive car. I’m not alarmed by it, but the car does get a short jog down the highway at about 50 mph when taken out.
