> First the starter question:
>
> Can these be "reconditioned" at a reasonable cost,
Brushes yes, I'm not so sure about the armature. If it's really
badly burned, the number of pieces you have to take apart might
make it more cost-effective to replace the starter.
If you go the reconditioning route, some good tips on burnishing
the brushes and contacts:
- Use Brakleen (or equivalent) to get the crud off the commutator
and the brushes
- Use a fine wire brush on a Dremel to burnish the surface of the
commutator; this will help remove any oxidation on the copper and
restore good metal-to-metal contact
- If you put in new oilite bearings, remember to soak them in oil
first as they're a porous bronze, but don't over-oil them or they
will gradually contaminate the commutator-brush connection (oh,
right, like all the oil dripping off the motor WON'T :-)
> Second question:
>
> There is no vacuum line attached to the advance on the distributer. The car
> was rebuilt about a year ago. The connector on the advance mechanism is not
> plugged with anything - just open.
>
> Is this acceptable? All the vacuum lines attached to the forward carb seem to
> be accounted for. Where would I attach a line from the distributer advance?
There might be a vacuum connection on the intake manifold itself. Some MGs
came with carburetor vacuum connections, some with manifold connections.
The disconnection from the distributor isn't going to cause much of
a problem, as there are still centrifugal advance weights in the
distributor. The opening to the manifold, however, is going to cause
a vacuum leak. You can check for it with carburetor spray if you
can't see it right off; spray carburetor cleaner (which is non-inflammable)
on the carb bodies, NOT the throats, and if the car stumbles, you have
a leak somewhere.
Remember also, if you replace the vacuum advance hose, that the hose's
internal dimensions are critical to the intended tuning of the car.
A larger-diameter hose, or a significantly longer or shorter one, is
going to have damping characteristics (like capacitance in a wire) that
will affect how rapidly the distributor vacuum advance responds to
changes in engine vacuum.
Note also that many racing/high-performance cars do not use any
vacuum advance, relying solely on mechanical advance to adjust
timing. This is because vacuum advance works mainly at low-RPM
and part-throttle applications, such as you encounter while driving
on the street. Virtually all ignition systems dial in full advance
before the midpoint of the RPM range -- it should be about 3000-3200
RPM on your B -- and therefore a racing engine almost doesn't care
about advance curves since the only time it should fall below 3000 RPM
is when the pace car is out. But for toodling along in traffic, the
advance curve will have a noticeable effect on your car's drivability,
and the vacuum advance is part of the whole story.
On the other hand, this means one less thing to check when you
set the timing. :-) Remember not to over-tighten the pinch bolt
on your distributor when you're closing up after timing the car.
--Scott
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