how long is too long for an engine to be open during engine work
 

i have the parts off down the the lower intake.
i plan to take off the lower intake and the heads.
the car is outside

once i get down to the block, is there a time period where i should start getting worried that it has been open too long?
i plan to order some parts and havent yet.
want to plan accordingly

like, if its open for a month, is that way too long?
how long, if ever, should i start worrying?


thanks

Well.... I would At least cover the engine up. They make engine covers for this, or at the least cover with a towel or some rags. Just check and make sure things arent getting rusty, or you may have to do some honing, which will require removal of the pistons etc.. Just pay attention to what you are doing and dont let it get moisture inside.