Geez, is this great or what? There sure is a lot of expertise on this list.
Thanks Kelvin, this is a "keeper".
Larry Hoy
http://pages.prodigy.net/larryhoy/
> -----Original Message-----
> From: owner-mgs@autox.team.net [mailto:owner-mgs@autox.team.net]On
> Behalf Of Dodd, Kelvin
> Sent: Thursday, September 23, 1999 1:26 PM
> To: Larry Hoy
> Cc: mgs@autox.team.net
> Subject: RE: MGB rear springs
>
>
> Larry:
>
> Let me get out my carpet duster.
>
> Rear Springs
>
> No idea. So far as I can tell the best way to go is get the spring
> with the correct number of leaves for your application. CB cars use less
> leaves than RB cars and GTs.
> Then fabricate spacers to get the car to the ride height that you want.
> Alternately Doug Jackson makes some nifty plastic springs. Problems with
> those are the expense, and they are now only available in one ride height.
> Again spacers may be necessary. The plastic springs are really
> of interest
> to those with V8s as the torque tends to rip regular leaf springs apart.
> (ask me, I know).
> Re-arching leaf springs seems to be troublesome, I've seen lots of
> failures. I think this may be because British manufacturing uses
> different
> hardening techniques and metallurgy than US.
> I will know more about this after playing around with different
> spring rates on my Bs. My GT V6 had new GT springs. The ride
> height is now
> pretty low, but those springs were damaged by excessive windup
> before I put
> on the locating bars.
> My racecar got lowered springs, that raised the car 1". I built
> spacers, the stiffer spring kept the inside wheel on the track and reduced
> wheelspin. But then I run a rear sway bar, so I'm not following
> the popular
> concept.
>
> Bushings
>
> I'm using all types.
> Rubber- Black, soft often of dubious manufacture and longevity. Only
> useful in fully supported situations. Typically designed to
> seize on ID and
> OD. Pivoting is accomplished by shear, not rotation. Drawback. Many
> people install with lubricant which prevents the rubber from bonding. The
> soft rubber then tries to pivot which it will not do well. Also these get
> installed with the car on a jack. The bonding occurs with the
> suspension at
> full travel. When the car is at regular ride height the rubber rips.
> When installed correctly there is no component to pivot movement, as
> the rubber bonds to the pivot, so no sqeeks.
>
> Metalastic- ID and sometimes OD is bonded to steel bushing. The
> ID bushing
> is typically clamped by fastener. The OD is typically an interference fit
> to component. Again rubber shear is used for movement. Again a major
> problem if the bush is installed in unloaded condition. Also ID
> bushing can
> rust to fastener or inner pivot. Greasing the ID prevents this.
> Since the
> rubber is supported these bushings hold up well. There should be no
> component to pivot movement, so no squeeks.
>
> Poly-urethane Usually red-black. Can readily be dented by fingernail.
> These pivot and work on the supporting surfaces. They do require smooth
> mounting surfaces. Since there is component to pivot movement
> there is the
> likelyhood of squeeking. Some manufacturers supply special
> lubricant. The
> softer poly bushings seem to be pretty quiet.
> Many kits include a steel sleeve which is clamped by the fastener. This
> gives a smooth, replacable surface for the bush to pivot on.
> Again, care is
> needed to ensure that this sleeve does not seize to the pivot.
>
> Nylatron- Compound of Nylon and Molybdenum Disulphide. These
> can be barely
> dented with a finger nail. I've had these on a street car for some years,
> and have been happy. There appears to be some wear to the pivot
> points, but
> nothing too worrisome. On the B the material works well for upper front
> bush (originally metalastic) and rear spring pad and shackle.
> These can be
> difficult to install as the material does not really give. I
> do'nt recomend
> them for inner A arm bushings, as the geometry of the assembly has to be
> perfect.
>
> Delrin/Nitrile- Very hard, cannot be dented by fingernail. Used
> on racing
> applications where no displacement is wanted. Geometry and condition of
> pivot points has to be perfect. This typically requires
> additional assembly
> time and effort. High wear in dusty (street) conditions. TRs use this
> material on the front suspension, but have steel pivot sleeves and rubber
> sealing washers.
> Delrin will crack when subjected to stress, the bush must be fully
> supported. I am using these on my race MGB inner A arm bushings. I have
> not noticed obnoxious noise or vibration transmittal in street use. (the
> car is muffled and uses street tires).
>
> Hopefully this helps out.
>
> Currently I have experience with the following types on an MGB, e-mail if
> you want specifics.
>
> Delrin- Inner A arm bushs
> - Upper F. shock bushs
> - F. sway bar end bush ***A disaster, the bush sleeve ruster to
> the pivot****
>
> Nylatron- Inner A arm bushs
> - Upper F. shock bushs
> - R. Spring Pads
> - R. Spring shackles
>
> Poly- Inner A arm bushs
> - F. sway bar bushings
>
> Metalastic- Inner A arm bushs
>
> Kelvin.
>
>
>
> > -----Original Message-----
> > From: Larry Hoy [mailto:larryhoy@prodigy.net]
> > Sent: Wednesday, September 22, 1999 11:18 PM
> > To: MG List
> > Subject: MGB rear springs
> >
> >
> > I know this has been beat to death before, what can I say? I
> > used to sleep
> > through some of my classes too.
> >
> > I'd be interested in comments from the group regarding rear
> > springs. I am
> > interested in these for my 1967 MGB vintage race car,
> > (roadster). It is my
> > understanding that the lower the better, but stiffer isn't necessarily
> > better. Apparently the front suspension needs to be stiff,
> > the rear a bit
> > softer. Moss shows 5 different springs in the "Accessories"
> > section of
> > their catalog. Any suggestions?
> >
> > Second item. Can someone explain the difference in the
> > following bushings;
> > rubber, polyurethane, Nitrile, Delrin, Nyatron. Which is
> > harder, are some
> > brittle?
> >
> > Thanks.
> >
> > Larry Hoy
> > http://pages.prodigy.net/larryhoy/
> >
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