ORIGINAL: Colorado_Mustang

I wish that were the case. I've had a 'self-burping' 302 crack open pretty quickly. I run a 1/8" hole in every thermostat I install, and warm up time does not suffer, nor does the ability to keep the engine cool. Which means the thermostat is working just fine.

ORIGINAL: Soaring

Never heard of it,. Not sure what you would be accomplishing. You need a bigger radiator, at least a 6 blade fan some wetter water, a shroud and an overflow.

ORIGINAL: Soaring

It depends of how much money you are willing to spend. You can get a 3 or 4 row copper/brass or you can get a 2 row aluminum one. If you want a really good one, get a Griffin or a BeCool aluminum. There is another popular one, but the brand sips my mind right now. Something Dyne. Maybe the younger minds can help out here.The brand doesn't really matter on the copper/brass core rads.

ORIGINAL: JMD

I know you already know this, but for the benifit of others, I am going to try and explain the dynamics of an air lock under the thermostat. I have not lost an engine because of an air lock,, but I have come damn close more than once...

It is a fact thatfrom time to time thermostats can and dotrap air behind them, this can happen whether the radiator is higher than the engine, lower than the engine, or just right in relation to the engine.

Thisissue can lead toa majorproblem when thecoolantis not actually touching the thermostat itself because an "air bubble" is taking up the space below the thermostat.Thecoolant gets very hot,and the air does not heat up so fast, by the time the thermostat opens, the car can be way (way, way, way)overheated, and therefore the engine may become damaged, this is not cool,,,,

I agree that an 1/8th inch hole drilled in the edge of the thermostat is good insurance, it costs nothing, and in the worst case, it will not hurt a thing. The"air lock" issue usually occorson the first start of a new engineor after coolant has been drained and replaced for one reason or another, sometimes when the heat guage has not been hooked up yet, and in the case of an airlock, you don't get the benifit of a "boil over" to tell you an engine is hot until it is way too late, usually when the thermostat opens.

And speaking of when the thermostat opens........ when it finally does open,,,,, all of the super heated water rushes out of the engine,,, and all of the cold water rushes in,,,,,, guess what happens now,,,, instant cracks, now the engine is junk.

ORIGINAL: mikethebike

I've had 427 Chevells that ran in the 11's, 305 Gurney-Weslake that made 470 hp on pump gas, BOSS 302's with dual X-BOSS inline 4's, HI-PO 289's and SBC's that were radical and I nevr had to drill holes in the thermostat to evacuate the system. I grew-up in Burlington NC in the 50/60's when Sox& Martin and Herb McCandless were racing and I never heard any of them talk about drilling holes in the thermostat.
Dan Perron in Charleston SC raced modified eliminater SBC'c that reved 13000 rpm and he never once mentioned drilling holes in a thermostat.
Not going to see me drilling holes in MY thermostat. You can do what you want though, it's your motor.