Have a 1946 Chevy 3/4 ton truck with a 1952 216 engine. In the process of getting it running and road worthy. The engine is overheating so am doing a flush. The manual says to drain the cylinder block but does not mention where the drain plug is located. Did a little Google search and think I have located the plug. See pictures. When I took the plug out nothing drained out? Am guessing it is full of crud? I poked a bit with a wire but no luck. Any thoughts on getting it unplugged. Thank you.
That's the plug. 70 plus years of crud build up is a guess. I used a wire hanger and finally got the crap out. Try left, right , up and down along the cylinder walls. Others will be by with some suggestions.
Try using various lengths of bicycle brake cable chucked in a drill. It will make some of the bends.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
A blast of compressed air into the hole will sometimes free things up.
Some years ago. I adapted a little pool pump to a container and circulated white vinegar through my engine, out the upper rad hose, back into a container, and into the the drain hole. My engine was a non-runner at that point. Probably more practical to use the running water pump to cycle whatever flush solution you prefer.
But before you try flushing, it would be good to remove what you can by prodding around, blasting with air, water, etc.
Adapt an air hose quick coupler to the drain port and connect a compressor to the port- - - - -leave the radiator cap off so the radiator won't be damaged when the pressurized air blows through the crud. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I had great luck with the Evaporust treatment that someone posted here. Prior to Evaporust, every coolant change water would only dribble out of the drain even when I used wire and brushes in the drain. This year after I drained the block and let it dribble out for several days I used Evaporust. I took 3 treatments - I let it sit in the block for a day or two each time. After waiting each time, I removed the fixture on the block and used a shop vac to suck out the gunk. The third time, when running the shop vac there was a "pop" and the Evaporust poured strongly out of the drain - no more dribble. I then rinsed it with water 2 times and the water gushed out clean. Then I rinsed once with coolant. As a hint, I disconnected the lower radiator hose L fitting and pointed it upward (Instead of down). That way I could pour the Evaporust into the block without pouring it into the radiator.
Finally got it unclogged! Used a drill, wire, dental tool, even made a copper tube with the end pinched and holes drilled in that I connected to the garden hose. The second time using compressed air it finally opened up.
When I restored my '37 I had to replace the head on the 216. The block drain was plugged so I commenced trying to clear it. After pulling the "freeze" plugs and removing the water pump, I had reasonable access to the water jacket through the top sides and ends. This is with the engine removed and on a stand. I was astonished that there was 3 to 5 inches of dense mud-like deposits throughout the jacket. I mention this only to emphasize that clearing the drain plug is good, but only a small fraction of the problem. I had borrowed a "Zoo gun" (named for city of Kalamazoo) which combines water and compressed air to remove deposits. This uses the radiator hose connections and it had only removed deposits for the forward 2 inches of the water jacket.
Over many days I was able to remove almost all of the deposits with a combination of long screwdrivers stuck through the various holes, flushing with water, letting it dry and vacuuming using a small hose duct taped to the vacuum cleaner, ect.
I don't know how that much crud could be deposited but I am told that antifreeze was not used that much back then (with it's associated anti-corrosive agents) water from a horse trough may have been used to replenish adding contaminents, ect.
During the restoration the radiator was cleaned so now I have a pretty clean system. I have no problems with driving in 110+ degree heat.
