🚀 go-pugleaf

koichi@unixg.ubc.ca (Koichi J Kishimoto) writes:

>>Actually, there is no corelation between engine size and allowable
>>emissions in the air care tests.  This is because the measurements
>>are ppm and %, the total volume of pollutants is irrelevant.

>When I called Air Care, I was looking for one set of numbers 
>applicable to all cars manufactured in 1992. The "technician" who
>answered the phone told me that this wasn't the case, and that the
>maximum allowable changed with engine size. He required specific
>model information, including engine size, before he could tell me
>it's emission requirements. 

>Without knowing more about the measurement technique employed
>by Air Care, it's impossible to comment further on the validity of
>the above statements.

The allowable emissions DO depend on the engine size.  For example a
'88 Ford Mustang (probably) has different allowable emissions readings
for the 4 and 8 cylinder models.  What I stated previously was that
"there is no correlation between engine size and allowable emissions
 in the air care tests".  What I am saying here (for the English impaired)
is that the 8 cylinder model (the bigger engine) may actually have lower
allowable limits for the air care tests.  This is because the numbers
used for air care are percentages and ppm (part per million).

kenb@ee.ubc.ca (Ken Buckland) writes:
>I was assured by three different muffler technicians (all from reputable
>muffler institutes) that exhaust system holes *do* suck air into the
>exhaust.

I would like to know the name of these "reputable muffler institutes"
so that I may go to their libraries and examine the latest literature
on muffler hole air sucking.

>the air injection anti-pollution systems you describe normally inject
>right near (or at) the exhaust manifold do they not?

Yes, the air is injected into the exhaust manifold.
>At that point the
>pressures are much higher (due to higher temperatures and narrower
>channels) so air pumps are necessary.  The air must be injected at 
>this point because the idea is to promote more complete oxidation
>(ie.: CO -> CO2) - something that is facilitated by higher temperatures.

Two points here:
- The channels are typically not narrower in the exhaust manifold
- The idea is to also to use the higher temperature to burn any unburnt fule

Dave.