Steam Relief Tube experiment

[dr deuce]

In re-doing my CCKW engine with new freeze plugs and hardened exhaust valve seats, I discovered that the flair on one end of the steam relief tube was leaking. I could see it was damaged and not going to seal, so I put a plug cap on both ends and preceded for its maiden run.

I believe I have now confirmed my belief that the steam relief tube mess up the cooling circulation. See the civy engines do not have this tube. The early chevys and CCKWs had the tube going into the radiator via separate hose and fitting on the radiator

The Chevys have a valve on the back of the engine that controls the steam relief tube coolant flow. There is a tag on it that states that the valve should only be opened when ascending or descending steep grades.

During the run today, I pushed it to see if there were any problems. Everything was OK, AND the temperature stayed between 160 ad 165 which it NEVER did when I pushed it! So I will not replace the tube.

When I 1st got the truck, they had the heater connected where the steam relief tube is connected. It did seem to regulate the temperature better back then s it had a valve to close off circulation to the heater core (30 years ago)