Besides the cleats, maybe you can find a hole or two, that you can use to bolt the engine onto the crate.
Shrink wrap will only get you so far, depending on how many times the forklift forks get shoved through.
I would try to make sure that the weight is centered, so that if the forks do pick it up a little on the left or right, the pallet won't try to tip over (remember, they only use 3 slats on the bottom side).

Good luck!

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D