Hi,
Hmmm. The initial post that started this topic is only 16 days old... I'm
catching up!
I'll share all that I know on this subject. Well, maybe not _all_, but
enough to get you on track.
First to dispell some rumors - you _can_ make the Webers work with the
stock TR6 distributor. Most intake manifolds that I've seen (I currently
have four, possibly more on the way) for TR6/Weber setups have a tap for
manifold vacuum on them. You just need the proper adapter to get a small
amount of vaccuum. One setup I have has a dual "tap", one larger pipe to
feed the TR6 vaccuum assist brake servo - you want this is you can as your
brakes will continue to work as they were designed... The other tap is
smaller, adequate to run a small hose to the vaccuum can on your
distributor. Any Weber "dealer" should be able to help you out with the
fittings.
Now, you didn't say exactly what distributor you have, so I'll make an
assumption or two.
The later cars all had a vac. _retard_ only setup. My '74 had this setup.
The advance springs on the '74 are very wimpy. What I eventutally
discovered with my car was that the dizzy needed to have the vac. retard
connected, or I would get full or almost full advance from the mechanical
advance part of the dizzy - at idle. Therefore, my entire advance was
whatever I had at idle plus a little bit, maybe a degree or two. As you can
imagine, this was sub-optimal, I could time for power, but the thing ran
lousey below 3000 RPM's, where street cars spend much of their time...
You could re-curve the unit for mechanical only advance... but you need
access to a distributor machine, and these seem to be getting more rare all
the time.
Ideally, you want close to TDC for the static timing and you want something
like 20 or 23 degrees _total advance_ for this setup. Total advance should
some in at around 3000 RPMs.
If you decide to recurve your Lucas unit, you may need to use some trial
and error to get things right, but if the best you can do is a 12 degree
"plate", then you'll have to set your initial advance to 10 BTDC to get the
total advance numbers quoted above...
So, what do you do???
You mention having a tach drive... this is a problem.
If you can lower your standards, you could buy a Mallory dual point unit
from TRF or Moss, but you'll have to skip on the tach drive. At least I
couldn't find one... but I never tried calling TRF or Moss about it. My
local Moss reseller was not able to come up with a Moss unit with tach
drive, so I suspect they (and TRF) sell the Mallory 2367801 (followed by an
H or M, I can't tell), and it does not have a tach drive.
The one drawback to this setup is that it comes sans the drive dog, so you
have to drill the shaft for the roll pin. This operation is not simple, but
doable if you have access to a drill press. If not - hand it off to a pro.
Anyway, with the Mallory unit and some basic tuning, the thing will run
great. I did get mine to run okay with the stock dizzy, but I also
converted to a Crane electronic ignition and then played with the spark
plugs to get it to run "right".
I wound up with Accel 116 (NON RESISTOR!!!) plugs gapped to .035 using an
Accel or Mallory high performance coil. That setup ran great, and I drove
the car something like 12000 miles in a year and a half with it. It was
rock-solid reliable - started every time on the first try, got something
like 23 MPG on the highway, and the car would pull past 6000 with ease.
The one problem with the Mallory dual point units is the lack of tach drive
on the units that seem to be available right now. But with $50 to $75 and a
little creative engineering, you could buy a cheapo electronic tach and
swap the guts of a mechanical Smiths units so that it "looks right". If you
have a few more $$$ burning a hole in your pocket, you can get one of the
instrument repair places to convert the tach for you to electronic...
depends on what you want to do.
But the bottom line - the Webers will work, the car can be made streetable
and it will work pretty well. You just need to be honest with how you
intend to use the car and then tune accordingly.
If you have further questions, I'll try to help, but you should start
looking for a local Weber expert with dyno access if you ever want to get
your car just right.
Oh, and Greenfield Imported in Greenfield, MA is a pretty good source for
Weber parts, I've bought thousands of $$$ worth from them.
Regards,
rml
=====================================================================
Bob Lang | TR 6 Guy | Editor: New England Triumphs
Phone: | 617-253-7438 (days)| 781-438-2568 (eves)
Occupation: | ComputerZ | TR fixer-Upper
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