blown radiator

[Bill]

About 2 months ago put in a new radiator, while I had it apart I replaced the thermostat. I put in a Stant 14068 thermostat and a DeWitt A90M radiator. After about 500 miles the radiator started leaking. I pulled it out and sent it back to DeWitts’s. Tom checked it out and said it had been overpressure. 90% of the tubes were ballooned out the end caps were also expanded. These end caps are made of .060 inch thick aluminum, that took a serious pressure excursion. I had reinstalled the stock radiator to keep the car running. After about 500 miles the same things happened to the stock radiator. Before replacing the radiator again I checked out the whole system. The only questionable part was the Stant 14068 thermostat. Evidently the pressure relief function of the thermostat was not functioning properly. After several conversations with Tom DeWitt I put the stock thermostat back in with another new A90M. The radiator in ALL of the C4’s are the same. The LT5 engine was designed with a much higher water flow than the other C4 engines. The radiator was designed for the standard engine. This means that the by-pass feature on our ZR-1’s must work or the radiator (weak point) will break! From what I’ve learned pressures inside my radiator exceeded 50psi to cause the damage that it suffered. I am attaching pictures of the stock & Stant thermostats and the housing. BTW I don’t see how the thermostat can be put in backwards. It simply will not fit.
Stock thermostat

STANT 14068

housing


Thanks for reading