Ive heard of rust killing blocks that were left in the hot tank over the weekend.
Dont get your hopes up.
I really do hope it works out for you.
Take it to a reputable machine shop for a visual and hopefully they will be honest enough to tell you whether or not it is salvagable.
I realize yours ripped but I like to tent mine at the aft end, so the moisture has somewhere to go.
I ALWAYS see people cinching there tarps down tight all the way around and if moisture cant get in, it cant get out.
Its gotta be covered but let it breath.
Even if no water gets in, the condesation alone will get into your exhaust ports, and it will oxidise the fock outta your alumineeum.
-beerjet-
The reality is that a machine shop is going to have to clean it up until the pits (if any) are gone.
Or not...
-beerjet-