Drilling the thermostat??

[RICK LAKE]

Undy I have 1 3/16" hole in my thermostat. I am also using Dodge thermostat The outlet is 1/2" larger than the FE one. You where talking about spikes with coolant temp. I am running a shelby 482 motor and the heatup is quick for coolant, 2-3 minutes, the oil takes about 5-7 minutes. The thermostat is a 180. I had a overheat problem and spike temps, I changed everything. The biggest change was getting rid of overdrive pulleys. I had the March setup. They provided just enough flow to keep from hitting 225 when roadcourse racing. I limit the run to 5 laps. I am now running custom pulleys that are 5 1/2" crank and 5 3/4" waterpump. The temp after racing is in the 190's I still get the temp spike in the 190's until the thermostat opens but I get a drop to the 160's quick and after a couple minutes of driving the coolant is stable a 180-185 with the motor at idle. March makes a nice pulley kit for FE's and on the street they get by as long as you are not in a stand still for a long period of time. The under drive is about 20-25%, and IMO thats too much. ASP built my custom pulleys. I do have the bypass hose on and working. The dodge thermostat does out flow the FE one by alot. If you go to an autozone of pepboys and look at the back where the outlets are you can seen the differents. The only thing is you need to remove 2mm on the edge to fit in the stock location on the manifold. Like said before hole goes on top for air. Hope this helps Rick L.

[undy]

Rick,

Are you running the pump bypass or is it hooked up? I might have missed it in your responses.. IMO, I need to drill enough holes to give me the approximate volume that the bypass line had. I would assume that's a Ford designed predetermined flow that's required. No way one or two 1/8" to 1/4" hole will give you that. It looks like Gessford had already figured that out. Given the ID of the bypass hose I would think, as in Patrick's post, that 4ea 1/4" holes would approximate the volume of the bypass hose. I can calculate it closer mathematically too. Overheating isn't a problem. My pulleys are of the right diameters. The only problem is the intitial temperature spike before the t-stat starts to modulate.
dave

[Chaplin]

FWIW, I have the bypass hooked up and have my t-stat drilled as Gessford suggested- works great with no problems at all.