🚀 go-pugleaf

In article <dpuarf$1n7@u1.netgate.net>,
 geoffm@u1.netgate.net (Geoff Miller) wrote:

> Ernie Klein  <ecklein@pacbell.net> writes:
> 
> > A cold engine emits a lot of water vapor -- you have seen the white
> > vapor coming from the exhaust of cold cars on a cold day. 

Poor choice of words I guess.  I should have left out the word 'cold', 
but I guess I was trying to convey two things: the engine, and by 
default, the connected exhaust system is cold; and the engine (hot or 
cold) emits a lot of water vapor.

> That vapor condenses as the result of the exhaust pipes being cold,
> not the engine.  It's the same principle as that of contrails: hot
> gases containing water vapor pass into a cold environment, where 
> the vapor condenses.  As more and more warm exhaust passes through 
> the exhaust pipes, they warm up down their length until at some 
> point, no more visible vapor comes out. 

I think we are saying the same thing.  The heat coming from the engine 
(exhaust) heats up the exhaust system.  The exhaust contains a lot of 
moisture.  If the exhaust system never gets hot enough to evaporate the 
moisture, it will remain in the exhaust system and hasten the failure of 
the system.  It all starts with a cold engine and cold exhaust system.

> Moreover, the water content of the air that's taken in by the engine
> obviously isn't a function of how warm the engine is.
> 
Probably not.  I believe most of the moisture in the exhaust is the 
result of combustion.

-- 
-Ernie-

 "There are only two kinds of computer users -- those who have
 suffered a catastrophic hard drive failure, and those who will."

             Have you done your backup today?