[Healeys] BN2 Caster Angle

[Michael Salter]

Re:
*Still wondering how adjusting camber, for instance--zero camber is
recommended (newer cars have slightly neg. camber)--for the radial tires
most of us run is a hazard (assuming it's done properly). *
I would have completely agreed with you Bob until I started doing some
basic designing of front suspension systems.
Although changing the camber may seem like a small thing you would be
surprised at how much a small adjustment in any of the suspension angles of
dimensions affects other things including "kingpin offset" and "bump steer"
each of which can have a profound effect on ride and handling.
As an example I have a Mitsubishi 3000 GT VR4. This car has 4 wheel
steering but I don't think that is relevant.
When I bought it fancy alloy replacement wheels had been installed. These
wheels moved the front tyre contact patch outboard around 1.5 cm.
The car was absolutely horrendous to drive with profound torque steer upon
the application of full throttle (320 BHP), appalling "tram tracking" and
incredible tyre wear.
I had another 3000 GT come in for service and as a test fitted the wheels
off that car onto mine. The transformation was absolutely unbelievable;
both the handling problems vanished completely.
I almost managed to talk the owner of the other 3000 into swapping his
regular wheels for my fancy alloys but just couldn't do it and came clean
by letting him drive my car with the alloy wheels back on.
Small changes can have VERY LARGE consequences.
M

On Wed, Jan 6, 2021 at 11:22 AM Bob Spidell <bspidell at comcast.net> wrote:

> That's odd; the bearings should be immersed in grease (although I've
> wondered how well greasing the top trunnion works, as a lot gets squished
> out).
>
> I installed the Torrington bearings on my BJ8 years ago; I thought
> steering effort was reduced a bit (but I think part of it was confirmation
> bias). Agree that it would make more sense to install them on the bottom,
> load-bearing, trunnion.
>
> Bob
>
> ps. Still wondering how adjusting camber, for instance--zero camber is
> recommended (newer cars have slightly neg. camber)--for the radial tires
> most of us run is a hazard (assuming it's done properly).
>
>
> On 1/6/2021 7:34 AM, Michael Salter wrote:
>
> I installed a couple of sets of those many years ago. Unfortunately the
> bearings were made from carbon steel not stainless and they rusted up after
> about 1 year.
> Hopefully the manufacturers now make them from stainless andor brass.
>
> M
>
> On Wed, Jan 6, 2021 at 9:49 AM Bluehealey <bluehealey at gmail.com> wrote:
>
>> These are the ones.
>>
>> https://www.ahspares.co.uk/austin-healey/big-healey/suspension-front/top-trunnion-bearing-kit-pair.aspx
>> Well worth doing.
>> The other often overlooked source of heavy steering is the Steering
>> Idler. It is rarely lubricated, has no real reservoir for oil, and a poor
>> seal at the bottom. I suggest releasing the ball joints that connect to the
>> drop arm to check it for stiffness. Complete removal of the idler isn’t a
>> difficult job and is the best way to clean and lubricate.
>> The caster is pretty good on these cars (the initial design was good).
>> Camber could go from positive to negative to be more compatible with radial
>> tyres. Also check and minimise toe-in. This has a radical impact on
>> steering feel when wrong (in either direction).
>> If after all that you still have problems, then go for the caster changes
>> you have in mind and tell us about your findings. The Team may learn
>> something.
>> The only other aspect that seems to vary from car to car is bump steer.
>> Some can be horrible on fast bumpies and others are on rails.  I’ve never
>> seen a decent treatise on dealing with this on our Big Healeys.
>> Have fun.
>> Alan - from my iPad
>>
>> On 6 Jan 2021, at 13:35, Team.net <lawrence.swift at gmail.com> wrote:
>>
>> When I rebuilt the front end on my BT7, I had the trust bearings at the
>> top of the kingpin replaced with bearings - made a huge difference in the
>> ease of steering.
>>
>> On Jan 5, 2021, at 10:36 AM, Bob Spidell <bspidell at comcast.net> wrote:
>>
>>
>> re: "The other two are factory fixed and too dangerous to play with or
>> maintain...even if Kilmartin makes the parts"
>>
>>
>> How so?
>>
>>
>> On 1/4/2021 9:40 PM, gradea1 at charter.net wrote:
>>
>> I'm with the philosophy "set the toe and let 'er blow" The 1/16-1/8"
>> toe-in is most important for proper tire wear.  The other two are factory
>> fixed and too dangerous to play with or maintain...even if Kilmartin makes
>> the parts. Hank
>>
>>
>>
>>
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