Been doing this since the 60's. I had no idea that there was ever a doubt that it worked. I agree that you only need a 1/16 hole but an 1/8 will have no negative effect, just a wee bit longer to warm up. Frank
Aside from the holes, you just have to make sure you have no air pockets in the heads, (especially fresh dry heads) as the BBC exhaust guides are water cooled and if you have an air pocket at one it can hang a valve and that is messy! Vacuum filling or if thats not on option, jack the front of the car up 12-15 inches. Good Luck! Andrew
I've got one o/t rig sitting out in the driveway that is a real pain in the ass to fill the cooling system if you don't drill the thermostat. I'm going to use Larry T's suggestion of drilling a 1/16 instead of 1/8 hole on the rig I am doing today though and maybe Momma will be a bit happier if it warms up a bit quicker. I drove it 60 miles back down off the Pass last night before the thing was actually warm enough to be comfortable inside. In 19 degree F weather too.
Wel, I beg to differ. I drilled a 1/8" hole in one and the engine promptly burnt up. I really don't think that forgetting to put oil in it had anything to do with it. Really....exactly what kind of "gearhead" friends do you associate with?
jimv: that one inch hose like you encounter on Ford "FE" engines is not that hard to install. Fold the hose end-to-end with a pair of pliers so that both ends face away from you. Spray some WD40 into the ends. Push down between the two metal tubes while releasing the plier's grip. Voila! Install the hose clamps. You're good to go.
Another textbook case of confusing correlation with causation. I have no doubt that there was a hole in the thermostat, and that it was in a burned up engine. I am also certain that I wore red socks yesterday, and that I did not get hit by a bus yesterday. Red socks therefor protect me from bus collisions!
This is the first time hearing about drilling a t stat but i will start doing it on the next engine that I build or change the t stat. Could someone post a pic of the stat with a hole drilled in so I know where to drill?
i think the guys logic is flawed if he thinks drilling a hole in a thermostat is going to cause any "burn up" of any engine..sounds like a mental giant to me. ask him to scientifically argue his point..at a minimum it will be good for a laugh
Let's remember that some people out there can make anything happen. And who would then blame something someone told them to do . . .
Been doing it for years now... (you'll make a mess every time without one on the Ford 300/4.9 in a GSE application) I use No. 30 (approx. 1/8") drill bit, No. 40 seemed too small for quick refills... Saves time & no more coolant puking out onto the floor while you're purging the air out... Works OK, 115F to -15F Apply foot to his backside to preclude the possibility of further interruptions...
Guys and Gals, it is possible to burn up an engine by drilling a hole in the thermostat. But you have to be an idiot and drill the hole into the expansion cylinder of the thermostat. Maybe the idiot, who the idiot in your gang knows, did this. It WOULD prevent the thermostat from opening, as the expansion fluid/wax would come out of the idiot-drilled hole instead of opening the thermostat valve. I'm just saying it IS possible, IF you put the hole in the wrong place.
Been drilling holes in t-stats for probably 40 years now, and have never had a problem. All of my O/T rigs presently are running with one 3/16 hole, and have no problems with cooling or warmup. I'm running a blown BBC with the bypass plugged with three 3/16 holes. Also no problem! Only problem I see, is with your "build buddy".
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