Clogged Exhaust

So...a technical question on flow. If a less restrictive exhaust wound present a lean condition, would a blocked header pipe (mud daubers) create a rich condition?

 

I'm not sure that the first part of your statement is accurate.

What creates a lean condition when switching from stock exhaust to headers isn't really about restriction, it's about resonance and flow. Well designed headers have equal pipe lengths to the collector, and are designed so that, especially at a particular engine speed, outgoing exhaust pulses from one cylinder will create a low pressure condition at the collector to pull the exhaust gases out of the next cylinder to fire.

Remove the exhaust entirely and you'll have less restriction (and a lot more noise) but you won't have more power, or even as much power. In other words, less restriction, in that case, will lead to a rich condition, because you would have just reduced the engine's VE by removing the exhaust system.

 

How disappointing. Please allow me to rephrase my question in a simpler way. If one of the head pipes of an inline four cylinder engine is partially clogged and everything else is to spec, would that cylinder run rich when it would otherwise run normal?

 

i kind of doubt anything could stay in a header pipe very long
oem head pipes are double wall, so that might be something

 

That was.my first thought. The pipe has been pulled and is clear but I still wonder. Good to see you again Polock!

 

and yes that would make it rich but so would a hundred other things
open the drains on the carbs, see what comes out. catch it in a glass jar.