Just getting started on a restoration of a '57 Chevy 3100. Lots of old British car knowledge but my first dive into domestic iron. I know where the engine block drain is, but this thing seems bizarre. Could a P.O. have drilled and tapped the block to provide another drain? I hate to remove it until I have an idea what it might be. And that is a wooden dowel on the end of the rubber hose, not a cork. Thanks in advance for your shared wisdom!
3100inSantaFe, 1st off, Welcome to Stovebolt! That being said, your question belongs in the Engine Shop so that where it has been moved for the best answers and further conversation.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
That's the oil canister return line. Someone removed the oil filter and plugged the line. Remove that contraption and screw in a 1/8 inch pipe plug
~~ Jethro 1954 3100 Back to Life In the Dity Gallery 1951 3100 (gone) / 1956 4400 (still in the neighborhood) / 1957 6400 with dump body (retired) / 1959 3100 panel (in the woods junked) / 1978 Custom Deluxe K10 / 1993 S-10 4.3 / 2004 Chevy Crew Cab / 1945 John Deere H / 1952 John Deere B / 1966 John Deere 2510 / 1967 John Deere 1020
Very well could be a circulating block heater connection. Looks like someone has installed an adapter in the core plug opening and tapped that for a pipe nipple. There would be another connection (maybe a tee in a heater hose) for a return. That was where a block heater was on my 216. But that was an insertion type heater with just the cord sticking out.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
It is a 235. I should have mentioned that! It has an 'accessory' style heater that mounts on the firewall. A donut style heater core with the blower motor in the center. I found the heater shown in a Chevrolet Accessory manual. But that manual did not describe where the hoses were to be installed. On this engine, one heater hose was connected to a port on the water pump. The other was connected to a port on the thermostat housing. So maybe the mystery part was used for the heater possibly before the PO found the option of either the water pump or thermostat housing port? So, a follow-up question. Where the pipe is connected to the block, could this be actually cast into the block? (and threaded?) I have looked at photos of blocks and never saw that option. Thanks again!
Regardless of what it was used for, remove it and replace it with a core plug or a solid rubber expansion plug.
While you have it out you can do a thorough flush of the block.
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
Thanks to all! I removed the rubber hose and clamps and as mentioned, this appeared to be a block drain. The 3/8 pipe nipple seemed to be firmly corroded in place so I chased the threads on the nipple, then used a galvanized clamp and Teflon tape and all seems well. Thanks for all of your help!
That being said, your question belongs in the 
