I read Larry Bichel's post on the list last week on his Weber experience
with the
TVR with great interest. Unfortunately I lost your email address so I
will post this up to the list ( listers forgive me if this is
redundant).
I bought a 74 TR6 with the dual downdrafts ( I recall that is your
setup) and can't get them running right. I do not know if any internal
work was done on the engine but I am 95% sure the cam etc is stock as
the Webers were installed by the immediate prior owner who had bought
the car partly in boxes and put it together then sold it to me. He made
no mention of doing any engine work other than installing the Webers in
August 96 ( I bought the car in Oct 96). I'd bet they are out of the box
specification for all jets, emulsion tube, etc.
I have the car running very strong on hard acceleration all the way up
and over 5K RPM. But it hates to run much under 2200 and once warmed up
really is rough on takeoff under normal driving conditions about town.
Not backfiring or spitting but more just rough running until under way.
When cruising under say 2500 RPM it gurgles more than burbles. I have
done my level best to optimize the engine timing by road timing it,
rather than using specs since the Webers change everything. I run an
electronic ignition with a hot coil, a TRF rebuilt distributor and the
right
plugs, so its not an ignition problem ( you can see I went down that
route first). The car has a new fuel tank, filters (they stay nice and
clean) and fuel pump and pressure regulator, so its not fuel flow.
Though I am only an amateur at all this, my understanding, and your
comments, point to the standard Weber setup being inappropriate for
normal street running speeds. I am running on the rich side ( based
solely on the exhaust perfume) but need
to be that way to get some, but not anywhere near all, of the roughness
out of the initial acceleration or low RPM driving. Your post and the
posts of some others seems to consistently state that the idle jets need
to be changed and now you also comment on the emulsion tubes.
I kept your specs on file for all jets, tubes and venturi, but I noticed
you said your engine was modified with a cam at least. Do you think
your proposed specs would help settle my engine down though it is stock.
If not, what changes to your specs would you recommend to run the Webers
on a stock block.
Again, I have never had experience with Webers. Can some of the jets
tubes and venturi be
changed while the carbs are mounted, or do they need to be removed and
reinstalled each time a change in components is tried?
Any other wisdom? Any other listers have ideas? I love these carbs when
I can open them up on the road, so there is no going back to dashpots
for this car!
Thanks
Keith Ehrlich
Concord, Mass
74 TR6
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