Yesterday was a holiday for some of us lucky stiffs, and so I decided
to take the TR into the local Boulder british car place to have the
emissions tested, and the carbs tuned. The owner of the shop asked me
to to leave the 6 there so he could test it as time permitted. I
agreed and went for a bike ride... Upon my return I asked, "What's
the good word?" He replied, "The front carb won't budge, the adjuster
is frozen... If you care to save some $$$ you can try to unfreeze it
yourself." Now, this was a new twist... Before, I had left him the
car, I explained that I had rebuilt the engine and the carbs myself,
and so I guess he assumed that I would prefer to wack on the carb
myself! Wow! So, in his shop parking lot, I removed the carb top,
and was able to free the needle with some encouraging words. :-)
We then hooked up the emissions meter, and he proceed to twiddle the
carbs. He turned more screws on the carbs in less time then I could
have moved one carb needle! We got the car to run fairly smooth, but
there was a spurious miss during the idle... I knew as long as the
car mis-fired every so often, that the HC's would be off the scale.
And they were. Just couldn't get them low enough. Close, but no go.
Anyway, I asked him what could cause this miss. He suggested that the
distributor may have a bad lobe on the cam, and thus the points
weren't behaving consistently. He took a quick look and said, "Wow,
You've got just too much play in your distributor shaft!" I knew that
there was some play in the shaft, but never connected the
ramifications. So, there we have it. This makes sense to me as the
car runs GREAT on the open road, but it has never idled without an
occasional miss-fire. I assumed that this miss-fire was due to a
higher profile cam, but I think the distributor may be aiding problem.
When the engine is under load, the distributor shaft is either less
wobbly, or the time the points are open is much smaller, and thus has
less room for error. Anyway, I asked, "How about we put an electronic
ignition in there? That should take care of the points problem." He
agreed that this was a good idea, but unfortunately, he didn't have a
unit in stock. I told him that I would like to return with the unit
installed and we could retune the car then. He said "Sounds great!"
I then asked what I owed for the hour work... He replied, "Don't
worry about it until we get it through emissions." Wow! He won a
customer that day! And, with the tuning he did on the car for those
moments, it runs better then it has in a long time. He will be
receiving some Guiness in the near future... :-)
The beauty about putting an electronic ignition system into the car is
that if I spend $50 on tuning the car, I can get a waver for the
emission test! So even if the electronic ignition doesn't fix the
problem, I can still get my car registered in Colorado! I wonder if
new front springs and shocks help emissions? Jean tried to tell me to
get rid of the points several months ago, and I should have listened
then. Jean, I owe you a beer. :-)
One of the tricks this guy mentioned to get the car through emissions
was to set the gap on the valves quite large. Like .002 instead of
.001! I asked why this would help, and he didn't know, but said that
it does work. My theory is that opening the rocker gap up allows a
smaller amount of air/fuel into the combustion chamber and thus lowers
emissions. Comments?
paul gilders wrote:
> Well the other thing I managed to get from the Triumph Spares
> supplier is a set of HS6 carbs and manifold from a Triumph 2500.
> They're in excellent condition and I'm surprised how simple the
> substitution appears to be. I'm hoping that I will be able to get the
> correct needles and any additional linkages this weekend - I shall let
> you know how the conversion works out.
Yes do! And let me know if the conversion helps emissions! :-) BTW,
paul, since your distributor may suffer the bogus point problem as
mine, perhaps you should look into an electronic ignition as well. It
might solve your problem too! (of course, I guess it depends on how
worn your shaft is...)
Cheers,
-Scotty "What's the point?" Paisley
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