Resend, maybe this fell email though the cracks 2 days ago. All I am after is
if 0.5 degrees less positive caster on the left is bad on a 100-4. Alignment
and tire shops recommend 1/4 (sometimes 1/2) less caster on the left to
counteract crowning of the road for daily drivers (and 1/4 more negative camber
on the right) Racers will create a bigger caster split to favor left turns.
thanks
Bert
Hi,
As I was going over my 100-4 BN2 frame one more time before sending it off to
paint, I noticed the left front suspension front A-arm bracket sitting higher
than the right one. Measurements confirmed that it is about 5/16" higher, the
rear A-arm bracket is about 3/16" higher than the left one.
This prompted me to re-attach the front suspension and re-evalute
camber/caster. I took multiple measurements with a digital level with a
magnetic mount that snaps to the hubs and I confirmed camber with a plumb line,
measurements and trig math using a calculator on the web.
Here's the results:
LH Camber 1.1 shop manual spec = 1.0
RH Camber 0.6
LH Caster 1.2 shop manual spec = 1.75
RH caster 1.7 (measured from -20 to +20 degree wheel rotation)
I could adjust the camber with upper adjustable offset bushes and actually
bring this close to 0 degrees which seems to be the current preference with
modern tires.
Note that the car is on a rotisserie, connected by the bumper bracket mounts.
It is easy to level the car. The car is not loaded, no engine/trans just the
frame + body panels so no flexing.
The caster numbers confirm the measurement of the brackets height.
1/8" of height difference between front and back compared to left correspond
roughly to 0.5 degrees. Adjusting the caster will require cutting and welding
brackets and probably shock plate.
But before I do that I would like to ask if a 0.5 degree difference in caster
is noticeable. These numbers could also change again when the frame is fully
loaded. I remember camber was measured at the reputable Healey shop where we
did the body/frame repair (left rail repaired with kilmartin sections) and was
exactly 1 degree on both sides with the car pre-loaded with 600-700lbs of lead
simulating engine/trans weight.
Upon removal I tagged the suspension according to the side of the car but the
previous owner could have swapped them around. So I might also test changing
the suspension from left to right and re-measure. Is this usefull at all?
Am I worrying to much over this? Is 0.5 degrees difference still within spec?
Should I just have the frame painted, the car assembled and see how the car
rides and bring it to an alignment shop and change things if required?
Looking forward for your advice and experiences
Bert
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