> I think I'd first inspect the lower arms with a straightedge and
> make sure they're not bent. Also, I presume the bushings are in good shape?
> As I recall, the camber changes as these wear.
Not a bad suggestion.
> I've seen one top-flight shop adjust the camber on my MGA by putting
> a shim under the shock absorber. Memory is dim, but I think he only shimmed
> the inboard (or outboard) bolts. This would tilt the shock slightly and
> change the camber by some small amount. Certainly shims are cheaper than new
> suspension pieces. Don't know how much you can really shim though.
A couple of differences between the MGA (which uses the same front cross-
member as "big" MGs from the TD through the B) and the Midget.
The MG[TD,TF,A,B] crossmember mounts the shock absorbers horizontally.
To get a small amount of negative camber (see Notes), you add a shim
under the outboard mounting bolts of the shock absorber. This lifts
the outer end of the shock, which pulls the upper suspension arm ever
so slightly inboard. It's the standard camber "adjustment" from the
Fifties on up.
The Sprite/Midget shocks are mounted on angled supports just inboard
from the inner fender liner. Because of the angled setup, you can
put a flat shim under the entire shock and it will move very slightly
inboard, also adding a small amount of negative camber. Or you can
put washers under the outboard shock mounting bolts (between the shock
and the chassis), tighten everything back down, and get even more
negative camber. Or you can install shorter front springs, which always
gave me visible amounts of negative camber on my '74 Midget (but
which didn't work as well as stock springs with a stiffer anti-roll
bar; never got around to trying the shorter springs/stiffer bar).
Camber Notes
Camber, for Our Friends Not In The Know, describes the angle of a
car's wheels. For the vehicles we're discussing here, camber is
limited to the front wheels, as the solid rear axles require zero
camber angles. Negative camber is the condition where the tops of
the tires are closer than the bottoms of the tires; positive camber
is the opposite. Camber is basically toe turned 90 degrees, but
where toe is measured in fractions of inches (or mm), camber is
normally measured in degrees, because the car's body is typically
in the way of the string-and-measureing-tape approach.
For sporting driving, negative camber is preferred as it keeps the
tire flatter to the road surface as the car rolls in high-load
cornering. This is particularly important with modern, low-
profile/high-performance tires.
On a vehicle like a stock Midget or MGB, especially if the tires
are close to the original specification (145 to 165mm wide, on
13" or 14" rims of 3.5" to 4.5" wide), a fraction of a degree of
positive camber won't be a bad thing, nor will a fraction of a
degree negative camber. Negative is probably preferred, but until
you start exploring slip angles, you won't notice, and your
car probably won't wear tires out that quickly. Certainly
there are other factors (inflation, toe, and shock condition)
that will have a greater impact on how quickly your car wears
out its tires.
Again, I repeat my earlier advice to Dean: The adjustable-camber
upper suspension components are probably a waste of money for
your Midget, unless you plan to develop a competition suspension
and you want to be able to change the static camber settings to
match different kinds of tires. And even then, note that most
competition bodies will not permit these adjustable suspension
arms unless you run in a class where you basically can't
hope to be competitive without spending a LOT more money.
It's a very odd double-bind that often crops up in competing
with old British cars -- the only people who will really use
the new good parts are forbidden by the sanctioning bodies from
actually using them. This is because the sanctioning bodies
are typically supported by major infusions of marketing dollars
from Nissan, Mazda, and Toyota, in whose best interests it would
NOT be to permit an MG or Austin-Healey that could outperform
one of the sponsors' cars at a fraction of the cost.
(Don't mind me, I'm having my usual "why should I re-up with the
damn SCCA when all they want to do is make people buy Spec Racers
or Miatas?" crisis of the soul. My membership expires in September...)
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