Dixie :
The actual tests, and limits, vary from state to state. It's a funny
situation, but our EPA doesn't actually have the power to pass the laws
that govern such things, they can only pressure the states to pass such
laws.
In California, until this year, the 'tailpipe sniffer' test was done at
idle and at 'cruise', which was no-load around 2500 rpm (I believe the
exact rpm varied from car to car, perhaps based on engine size). The
idle test was for unburnt hydrocarbons (HC) and carbon monoxide (CO),
while the cruise test was for HC, CO and oxides of nitrogen (NOx). I
believe the tester also checked free oxygen (O2), mostly to look for
exhaust leaks. There was also a long string of other tests, including a
visual for excessive smoke.
I have a printout for my 59 TR3A from 1982, which shows the state
standards as :
HC(idle) 1200 ppm
HC(cruise) 400 ppm
CO(idle) 8.0 %
CO(cruise) 6.5 %
NOx(cruise) no limit
Standards for a TR4A _might_ have been slightly stricter, since I
believe all cars delivered in California after 1964 were required to
have smog equipment, which I believe was actually supplied by the state
at one point (for a fee, of course). On my 67 Plymouth, the smog
equipment consisted of a PCV circuit (required by federal law, I
believe), a disconnected vacuum advance and a 'calibrated' vacuum leak
(which conveniently connected to the disconnected vacuum hose).
Starting this year, the cruise test is done on a dynomometer. I don't
know if the standards have changed or not, since I haven't yet had any
of my cars inspected. As part of the dynomometer deal, all cars 1973
and older do not have to be periodically inspected. However, they are
still subject to roadside sniffer tests, which the state is trying to
automate ...
Randall
Adrian Dix-Dyer wrote:
>
> Being in UK I would like to know what are the emission levels your TR4A is
> expected to pass?
> Is it simply a CO level test? or is there a lot more to it?
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