[Guest]

Hi
I have a 68 Coupe with a 289 that has'nt run in 5+ years that i just got. Well I have rebuilt the carb, new fuel sending unit, new tank, new fuel lines,fuel pump, spark plugs cap rotor and wires, changed the oil, and new battery just to get it running .
Then when I got it running it will run untill the thermostast opened then with the rad cap off will push water 8 in. into the air so I thought maybe it was the Thermastast so I changed it well now it puts water up 1-2 in. then settled so I let it run for half an hour maybe a big air pocket? and after a time it worked like it should and did not get hot Then started to surge up and down spilling water on the ground and was starting to get hot so disgusted i shut it off and noticed that it started to put out a LOT of steam to the point the when cool the radiator is almost empty I have no clue any help would be apreciated and thank in advance

 

[09Frank65]

You put cold water into the radiator.

You then heated the water to 180 degrees or so.

It expanded. Being trapped behind the thermostat it built up pressure head.

The thermostat opened and you didn't have the cap on and it REALLY expanded (pressure head ---> velocity head).

You poured it all over the ground. Now it's all gone.

Fill it back up and run it till the first surge. Then put the cap on and see how it runs. If it builds up too much pressure it will bleed (depending on what radiator cap you have). Make sure the overflow tube is in place.

Good luck. Sounds fairly normal to me!


Frank

 

[dailydriver]

Suggest you leave the cap on when doing this, and check it after it cools off. Do NOT remove the cap when the engine is warm, as this may be very hazardous to your health.

Another thing that may be happening is:
When an engine sits for long periods of time, a lot of corrosion takes place in the block. When you started it up and warmed the engine, a lot of the crud will come loose, and when the water surges into the top of the radiator, it plugs off the cores. Suggest you remove the radiator and turn it upside down. Stick a garden hose (or two) into the lower hose opening and pack rags around it to help seal off as well as possible. Have somebody turn on both hoses full blast. Observe the discharge from the upper hose opening (which is now resting on the driveway) and see if you don't have a lot of chunks being discharged. While you have the radiator out, blow water through the rest of the system both ways, including the heater core.

Reinstall the radiator and put in a Gano filter on the upper hose fitting. Run a good commercial flush through the system per mfgr recommendations. Pull the upper hose and inspect the Gano filter after finishing the flush procedure. Refill with 50:50 water:antifreeze, making sure to top it off after a warm/cool cycle. Do the warm/cool cycle thing with the radiator cap ON! Recheck every day, for a few days, to make sure all of the air is out of the system. If you are running without a catch tank, the normal level will be down from the cap an inch or so, just above the radiator cores, so there is never any need to fill it above that point, as it will just blow it out the next time it warms up. This should fix your problem unless it's timing related, so recommend you check the timing as well. Have Fun!