So what does the front engine mount do?

[Eric]

On a 4kq what exactly does the front mount do?  I looked at the wear
marks when I removed the engine and it looks like it only rubbed on the
driver's side.  As far as I know it has never been touched in the 200k+
miles it has lived so far.  The bottom of the support is open so it is
not supporting the weight of the motor.  The only thing I can come up
with is to help counter act the torque of the front drive wheels (maybe
also to the rear end?).

When they are new do they fit tightly side to side?

The reason I am asking is in making room for my FMIC I would like to
switch to a double hiem joint mount.  Since these can only counter act
movement in one axis this may not be enough.

Any thoughts?

Thanks
Eric Sanborn