crossmember update (more pics..)

[treed2@u.washington.edu (T. Reed)]

Al,

I'm afraid I don't understand. When you step on the gas the engine twists
axially around the side motor mounts, in the same direction as the wheels.
If you sit on the drivers side of the car looking at the driver side wheel
it is turning counterclockwise when the car is going forward. When you
accelerate, it turns counterclockwise harder and pushes down on the front
motor mount. The front motor mount is tied in to the crossmember bar, so
the force vector points straight down.

Perhaps you're thinking that the placement of the inner cv joint relative
to the axis of rotation at the side motor mounts would make the engine
twist the opposite direction as the wheels. If this were the case, why is
my crossmember cracked on the bottom rather than the top? Tension causes
cracking, not compression (or at least it takes a great deal more
compression to crack sheet metal in general)

Could you clarify your statement?

Thanks,

-Toby

On Mon, 3 Mar 2003, Allyn wrote:

> > First of all, the force vector acting on the crossmember points straight
> > down.
>
> umm, during a downshift perhaps, but the major load is in the upward
> direction, during acceleration. i think this makes your whole explination
> backwards (as far as tensile/compressive stresses), but it will work just
> the same.
> Al
>
>