first start break in

I wouldnt think you would have any problems if your cooling system is on par. I've seen guys put a garden hose in the thermostat housing too. When breaking in a new cam if you have any problems your supposed to shut it down right away. But if your worried about overheating you can always do it in intervals. It's not going to hurt the engine to run for 10 minutes and then cool down and run it for another 15 or so and then another 10. I had to do this one time because I had terrible neighbors. They would call the police anytime I was doing anything to the car for prolonged periods of time. Such as replacing floors, so Alot of cutting and grinding and whatnot. So when I broke in my new cam I ran the engine for about 10 minutes one day, then the next day I ran it for another 10 and then the day after that I ran it for another 15 minutes. I'm sure someone will say something about it not being good for it. But I don't see why it would be a problem unless someone gives me a bona-fide reason.