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Extremely smelly exhaust

Posted: Thu Apr 10, 2025 10:39 am
by advinnie
Hi all. I have a 1971 supercharged 1600 beetle with a scat 35 cam. The problem with the car is that the exhaust smells ready ready bad. If you was to walk behind it the smell stains your clothes and skin for hours. There is no black smoke coming out the exhaust nor are the plugs black to indicate a rich condition. The car drives just fine as well. I have set the mixture screws on the Weber DCOE to give the fastest idle speed. Both barrels of the carb combine into one tube if that makes sense?
I was wondering if it had anything to do with the cam and the overlap or is it running lean.
I one heard that a rich engine does not smell but a lean engine does due to the different gases a lean engine produces, but I don’t know if this true or not.
So what can cause this smell?

Cheers all

Re: Extremely smelly exhaust

Posted: Fri Apr 11, 2025 1:35 am
by Bruce.m
No idea but my wife says i stink if I’ve been doing some engine tuning etc with the engine running (standing next to exhaust). Probably modern fuels without a Cat to filter out or burn up smelly vapours.

Re: Extremely smelly exhaust

Posted: Fri Apr 11, 2025 11:53 am
by Volky
Hi,

I run a 2109cc 1970 Turbo Bug and when I turn on the car in the garage and outside being next to it my clothes get smelly, too. No black smoke or any smoke, just smells. Also, I don't run any muffler, just a 6" tube from the exhaust flange.

I just have an extra shirt in the car at least, just in case. :D