Used engine question - Audi content

["Robert B." <robbrauns@bb.eulink.net>]

Hi List:

I just looked at a 20V turbo engine for my project car and since the
motor is out of the car, I couldn't run it. But I noticed that where the
AC compressor sits (on the cool side of the engine (this swap is going
to be more involved than I thougt)) that there are 4 cast in bolt
studes, nipples, bosses (what are these things called, anyway?).

Of the 4 bosses, one has a snapped off bolt, 2 are OK and one is broken!

So, my questions:

1. Can broken bits of the cast iron block be welded back on?
2. If the car was hit so hard that the AC compressor broke off, could
the block have hairline cracks that will cause problems later on?
3.Since casrt iron is hard, heavy and somewhat brittle, how much damage
would a real hard collision do to the motor block?

Thanks in advance.

Rob
Germany