Actually, the cat from Van Caf� is quite a bit better than the Emico brand.
I've used both many times, and that one has more material, is better made,
and performs better in the CA emissions test.  

Cheers, 

Jeff

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Dennis Haynes
Sent: Friday, June 29, 2012 5:15 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: EPA and Vanagon Emissions-reducing Vanagon pollution.

The Emico brand cats are probably the better aftermarket options. Just take
a look inside and compare the overall diameter (flow) and length (contact
time) of the OEM and some aftermarket options. The Bosal and Walker are
amongst the worse units. Some units can be restrictive enough to also affect
performance. If everything is running right the cat should have very little
to do to reduce CO and HC but is really needed to reduce NOx. Again this NOx
reduction is what brought us the dyno emissions testing.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
pickle vanagon
Sent: Friday, June 29, 2012 6:01 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: EPA and Vanagon Emissions-reducing Vanagon pollution.

One middle ground option to consider on the cat (between cheapest and OEM)
is the cali CARB approved cats.

I don't want to start a flame war here about CARB but van-cafe does say on
their page that they notice a "dramatic" improvement in emissions when
installing them:
http://www.van-cafe.com/home/van/page_1678_275/catalytic_converter_calif_wex
tras.html

Anyone with first-hand experience (testing before and after)?

On Fri, Jun 29, 2012 at 12:37 AM, Dennis Haynes
<d23haynes57@hotmail.com>wrote:

> Proper maintenance, testing and operation is the key. The combustion 
> process has not changed over the years, only the tolerance of the
controls.
>
> Start with the fuel system. Make it is tight and that the vapor 
> recovery system works. This controls hydrocarbons being released into 
> the air from evaporating fuel.
> Do not over advance the ignition timing or during rebuild consider 
> engine modifications such as cam-valve lift/timing or increasing
compression.
> These changes and maybe even some engine conversion increase the 
> production of NOx. Make sure the O2 sensor system is working properly 
> and at catalyst replacement time consider the big bucks of OEM. I have 
> yet to see a replacement cat have as much material as the original.
> If you area has an emissions test program and you fail, get it fixed?
> Working right it will pass any states-local requirements easily.
> Failures for our years always mean something is wrong. No temporary 
> adjustments or magic chemicals should be needed.
>
> Then there is all there other stuff such as tires and alignment and 
> brakes not dragging. Slowing down can also make a huge difference. If 
> 30% more fuel is used at 70 vs. 55 not only do you make 30% more 
> greenhouse gasses/mile but the increased loading will further increase 
> the production of NOx which the Water boxer does not have EGR to help 
> control it. The three way cat and O2 sensor have to do it.
>
> Dennis
>
>