If the end of the pipe is screwed into the block, I think it was added by a previous owner to make the coolant drain from the block easier. Looks recently added. Probably replaces the block coolant drain plug or pepcock that used to in that block.
please post a better pic, without that hose blocking the view but i agree with the previous poster maybe the previous owner of the car had trouble getting air out of the cooling system?
found this on another forum: Buick straight 8 overheating - need some help here. First off......hello. I'm brand new to the forum. I've read the posts for awhile but didn't join until I picked up my new find, a 1949 Buick Roadmaster. Anyway, the previous owner had the car running, but never registered it. I checked the anti-freeze...........full. Radiator seems to be in decent shape. I drive the car about 5 miles and the temp gauge climbs; however, it doesn't overheat until I shut the car off...then it pukes out about a quart of anti-freeze out the overflow tube. I checked the 160 degree thermostat and it opens at temp. The bypass valve has been replaced with the factory upgrade fixed oriface housing. my hoses are good and no leaks. I did notice the drain cock behind the distributor does not drain coolant when opened. I stuck a small screwdriver in there and no coolant flows out. I could use some advice here before replacing the radiator or ripping the freeze plugs out to check for buildup. answer: Buick straight eights were famous for plugged water passages in the block. In the dealership I worked in in the 60's the mechanics pulled the rad and sent it to the rad shop to be boiled out and then they mechanically cleaned out the block. Some engines had five and up to ten pounds of crud in the water jackets. so maybe the previous owner had enough of the crud building up in the engine and decided to place that drain valve to drain the crud from time to time before it could cause overheating trouble? link to the aaca forum thread: https://forums.aaca.org/topic/175565-buick-straight-8-overheating-need-some-help-here/
Straight 8 Buick's had the coolant block drains on the drivers side of the engine. Don't have the slightest idea what that piping arrangement is for??? The oil galley's are on the right side of the block. Maybe has something to do with oiling???
in the post on the other forum the owner of the car typed this: I did notice the drain cock behind the distributor does not drain coolant when opened. on this straight eight the distributor is on the passengers side of the engine:
