Quote Originally Posted by VRaptor SpeedWorks, LLC View Post
Any idea of how many/what size holes would have to be drilled in order to prevent the engine from overheating and also still provide proper t-stat operation? I guess I never really understood the design of the t-stat/WP in that regard....what is the purpose of having the t-stat seal off that other part of the WP? Why not just make that a solid casting?.....or make the proper sized opening/bypass there in the first place to always provide enough flow so that engine doesn't overheat? I've always viewed the whole thing as completely bass-ackwards from what it should be.....which is why this whole thing is such an issue in the first place. One of those things that GM should have used 100 years worth of "this is what works" and stuck with it instead of making some thing so simple into something that doesn't work right.
I think the problem was likely packaging once the fuel injection throttle body was put where the thermostat housing was on a small block Chevy. It should be noted that the stock thermostats DO have a small hole in them, presumably to keep water flowing in slight amounts to the other side of the thermostat, and to also keep air from being trapped as the proper placement of the stock thermostat is to place that hole at the top of the housing. That said, it is important to note that the original design of the LS engine always, as far as I know, incorporates the use of a heater bypass valve. It is simply part of the systems design. You can find cheaper and easier ways around the problem, heck I tell people constantly that a heater bypass valve really isn't needed, and neither would your solution be for that matter, if they just want to pay attention to what they are doing and make sure that the Vintage Air control valve is not closed during a warm up cycle. Simple as that.

If you don't want to go to that trouble, and you want the solution that the OEM designed into the system, then that is the use of the correct heater bypass valve components.