Steve Johnson says if you are thinking of taking a spare engine on the Brick
Trek, maybe you should just install it.  Two comments:  if you just install it,
rather than bring it, nobody but you can use it.  Also, back in the 70s, just
about everybody had a 1200cc engine, good running condition, dollar value about
$43, off in a corner of the garage, or even a corner of the VW bus, referred
to as the spare and turned over with a wrench every month or so.  You'd have
thought that's what VW made them for.  Bringing a spare engine is good 
discipline because if you have what you need to swap engines, you have enough
for lots of other disasters as well.
B.