stopping rust in a 4 year old race motor

[Crew Chief]

I have used the product CLR with great results. CLR is Calcium, Lime, Rust. In Canada any hardware, department store will have it. I had a friend who bought a used Corvette. When a hydrometer was used to check the antifreeze, it was so brown/cloudy it couldn't be read!! I dumped it, then put water and a quart of CLR in it and went for a ride. When we go back we drained it out and man it was unbelievable how much crap came out!! I ended up doing that 4 times before we got it cleaned out. I wouldn't leave it in there for any great length of time but it sure works to clean out a cooling system.