Rusty block coolant passages. does it affect?

When I built my motor 5 or six years ago I had the machine shop hot booth the block when it came out it was still rusty in the coolant passages. If I drive the motor like this will it help cause overheating or anything else bad?

 

little surface rust and discoloration or a blockage? if they are clogged it can cause over heating, little rusty walls, probably none the wiser

 

Oh ok, it was surface rust. so i guess im in the clear. They were blocked i think at one time. Sorry, having a five year ago flashback.

 

Any raw cast iron will get surface rust after a while just sitting around. Put coolant in it, run it and you'll be ok.

Bob

 

if your really concerned and want to clean it ... grab a cup-o joe and read the thread i started http://www.jalopyjournal.com/forum/showthread.php?t=408074

 

Sweet, im gonna have to try that one. thanks drfreeze!