As in, how long would it take a big block- cranked up from stone cold with NO cooling water to get hot enough to hurt anything at idle? I have always assumed that around 1 minute or so would not hurt anything. Anybody have any different knowledge/experiences? I have always pulled my driveline and run it on the trailer for a minute or so after I get it home to try and dry the headers. I seem to have a problem with moisture and my valves/rotating assembly getting stuck when I store it away. I even fogged it with WD-40 when I put it away a few years ago- and it still stuck- to the point I'm having problems getting it straightened out. Wondering if I could have hurt something trying to 'dry it out'.