Greetings,
I have been watching the list and read all of the mail on
idle/emissions/ignition with great interest. Mostly because my '72 has
some interesting idle problems itself.
On the temperature controlled retard switch (this is on my 72), I have
found it IS needed to make the engine perform properly. Being from
California and knowing that they added a similar switch during the late
'60s/early '70s for emission control, this is read make the engine work
less well but pass the smog test. I happily left this switch off. The
list made some interesting comments on engine idle vs. temp so I did some
research. As usual I found that the Brit's do things backwards. We have
vacuum retard as opposed to vacuum advance so the temp switch was
installed in the radiator line.
Experiments have shown that my engine is much better behaved with the
switch installed. Where idle wandered around between 500 and 1100
depending on temp it now seems to sit very nicely at about 650. While this
changed when the switch went in (so I'm leaving it) I'm not convinced it
should have had this effect.
I also saw some questions on the PVC valve. Mine is gone, so I chatted
with our local shade tree mechanics. The consensus was that if it was a
Chevy 350 leave it off. But on an engine that has relies on vacuum to
dynamically adjust the carbs it might be a good idea to leave it on. The
theory being that there is a certain amount of restriction in the valve.
I have a new PVC and will install it this week to see how that effects the
engine.
While looking at the Moss catalog
(http://www.mossmotors.com/cgi-bin/db2www/mossmotors/MossUSA/Shop/ViewProd
ucts.mac/report?T=37085&ModelID=41000&PlateID=3729)
I found another interesting part (index 82 ) identified as a "Restrictor"
which is installed in the major vacuum line going from the charcoal
canister to the carbs. I wonder if 1. do others have this device
installed and 2. is this another thing that needs to be there to make the
engine behave properly.
As an aside, and not meaning to cause problems, I've found that the
restoration/repair part of these cars is almost as much fun as the
driving.
Stephen L. Hanselman
1972 TR6
tr6@kc4sw.com
Manager, Defense Systems
Datagate Incorporated
+1.775.882.1313 x253 (voice)
+1.775.882.1689 (fax)
Stephen.hanselman@datagateinc.com
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