Daniel Levitin wrote,
>I have a '66 Alpine with the stock Stromberg 150CDs. I just had to have
>it smogged for California emissions. It didn't pass at first, but after
>fiddling witht he timing and leaning out the mixture, it passed with no
>problem. I don't think there is a "magic combination" of after market carb
>components necessary to pass, the car just has to be in good tune.
I believe that Daniels statement is the bottom line.
With the exclusion of engines modified for performance, a well kept and
reasonably tuned car, should not worry too much about failing smog.
Smog testing for the older cars have quite a bit more lattitude for passing
than do the newer cars (wider emissions acceptance criteria).
The only tested emmisions parameters are for Hydrocarbons and Carbon
Monoxide.
With few exceptions, the acceptable HC and CO levels are somewhat higher
than the original factory emmisions specifications for the given model year.
As for the Strombergs carburators, the age old problem with them is when the
throttle shafts are worn, too much air leaks around them and thus bypassesm
the variable venturi. In order to get the car to idle OK, the main mixture
adjustment must be tweeked unnaturally rich. When the car is run at higher
RPMs and loads, the ratio of air that leaks past the shafts is small, and
the engine runs really rich.
A simple fix for the worn Strombergs for me was to use 4 valve guide seals
and some grease. The valve guide seals seal the carburator casings to the
rotating throttle shafts. The carburator can be used, and should be able to
pass smog, assuming nothing else is wrong (replace the throttle shafts at
your leisure).
Another thing to remember with strombergs, is that there is now provision
for air density compersation, nor for temperature compensation.
What this means is adjust the mixture in the same altitude and approximate
temperature as how the car will be tested( a 20 degree C difference in
temperature will impart a 6% change in air fuel ratio).
Jarrid Gross
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