Lucky86

Im about to change my thermostat to a 180 from napa, but here i keep reading about "drilling it". Why is this done and how do i do it. Thanks

92ragtop

It helps to avoid air-locks in the cooling system. Drill a 1/8" hole in the flat metal between the hoop and the edge.

Scootin_Z

Sorry to hijack, but I'm chasing down cooling issues and spotted this. What exactly is an air lock in a cooling system and how do they occur? Also what is the best way to bleed these cars to make sure the air is out of the system?

Thanks!

vetteoz

What year?
Proceedure varies by engine type

Scootin_Z

Sorry... 95

enventr

You have a bleeder screw by the thermostat housing.Open screw very slow to let out air out of system.Be careful and place a rag by the screw

don hall

No reason to hijack a thread..... start your own thread.

JrRifleCoach

Check this link out

PLRX

Here you go buddy.

Scootin_Z

Sorry...was just a quick question and was trying not to make a fuss...

Carry on....

RollaMo-LT4

What the hell you drilling Pete?

ghoastrider1

drilling the stat is a really old racers trick. Running without a stat, the coolant circulated to quickly, so didn't have enough time spent in the radiator/engine to properly cool. The racing engines needed a bit more circulation than stock, so drilling 2 holes in the thermo was the answer. Not sure if it goes back to the early 50s (flathead days), but I know it was used in the 60s. The holes were drilled in the flange , close enough to the spring tower so coolant could still pass thu. Not sure what all this thermo stuff is about.. the thing doesn't help cool nor hurt it (modern days). Its job is to allow water temps to come up quickly to operating temps.I bet when you change thermos, you will see no difference in operating temps.

desertmike1