Date: Sun, 8 Feb 1998 21:11:24 EST
Joel Widell wrotre:
>I'm considering a suspension rebuild on my 77B as soon as S. Florida MG season
>is over(June, when it gets too hot. Feb. is the perfect weather!. Perhaps
>someone in the know can answer some questions before I start.
>1. Should I "lower" the suspension for handling purposes? (note-I have shock
>conversions in the front and rear, and have 185-14 tires. Would there be a
>clearance problem if I lowered the suspension?)
I run 185/70-14s on a lowered rubber bumper 'B. No clearance problems,
however,
lowering a RB MGB is a topic of great debate in MG circles. Here's the
lowdown:
If you signifigantly lower a rubber bumper MGB, you will induce some
bump steer.
This affects transiant handling and can make the car spooky to those
without
sharpened skills. There are ways of getting around the bump steer.
1) Install a chrome bumper crossmember. The CB crossmember has the rack
in
the correct position for the lowered stance. The bump steer comes about
because
if you simply lower a RB car, you are working in the top 1/2 of
suspension
movement, where the tie rod is angled up. With this extreme angle (a
difference
in the static height of the tie rod end and the center of the
rack--compensated
for in the mountings of the CB crossmember) the tie rod describes a
smaller
radius than the wishbones, resulting in the toe-in under suspension
bounce,
scaring the unprepared driver.
This would also happen in a stock RB car if you hit something hard
enough to get
the front suspension to full bounce. Basically the further you go in
the
suspension movement the worse the bump steer is (in a stock car) and
with
just lowered springs you're working in the upper limit of the
suspension.
2) Do various tricks with modified steering arms and Heims joints et
al. Not
advisable unless you've got the right tools and people. This is the
route
I'm taking. Why? Well, I'm sticking with the RB crossmember because
it's
the easiest way to get a Rover V-8 into the car. But, along with all
the
extra HP, I want better handling. I'll be driving my 'B in E Modified,
and
I want to have at least better than stock RB handling. Again, don't
fool with
steering arm mods and so forth unless you've got the right stuff. I
don't
do the mods myself: I do the basic engineering and take the parts to
someone
with far greater experience with metallurgy than myself. This is a work
in progress, involving some racing bits and lots of steering arms
that've
been scrounged. What I've done so far seems to help, but I'm not
finished yet,
I'll give a full report when the steering is tuned a bit better.
I think it's probably possible to lower a RB 'B some without causing too
many other problems, maybe 0.5" ~ 1". For better general purpose street
handling, go with a good sway bar set.
>2. Are the "V8" bushings better?
Yes. No question about it.
>3. The spring replacement is pretty straightforward, but I've yet to
>understand the kingpin situation. How does one tell if they're bad, and what
>exactly is "reaming" the kingpin?
Bad kingpins will clunk and have play. "Reaming" is a machining process
related to drilling, however more precise. The kingpin ream for a 'B
has two different diameter cutters, so that the two bushings in the
kingpin
have holes with the same centerline. Two options here: buy the ream,
or
buy a complete set of kingpins/spindles.
-Keith Wheeler
Team Sanctuary http://www.teamsanctuary.com/
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