No, the coil is actually a bimetal strip, which is two pieces of metal having different expansion coefficients. They are laminated together and wound into a loop. When the coil is heated one side expands more than the other and the coil winds tighter. You adjust the coil by tightening or loosening the coil to reach the proper balance between the tension from the coil and the weight. The operation is explained in the Truck Shop Manuals.
Again, BE CAREFUL when spreading the shaft, they break real easy, then you’re sunk.
My only answer to the belief that the thermostatic control is not needed is, that the bean counters at GM would never have allowed the engineers to have wasted the material and time on it for all those years that it was part of the system if it weren’t necessary. But, I guess some backyard mechanics know better than a staff of GM engineers with seventy or eighty years experiance. Might I also add that every other engine manufacturer equipped their engines with a heat riser also. So as I said, believe what you will, it’s your engine.
Denny Graham
Sandwich, IL
Last edited by Denny Graham; 11/05/2010 12:10 PM.
