Gary Lewis Posted February 26 Share Posted February 26 Thanks! Thats a good idea. I have done just that to stand-alone test of a radiator. I think an air based test is more thorough. I tried to drain the coolant last week but the block drain plugs are hard stuck and I don't want to mess with them I'll need to turn it upside down to flush it. And you'll be able to hear the air hissing out in the cylinders if, perish the thought, there's a leak there. Link to comment Share on other sites More sharing options...
viven44 Posted February 26 Author Share Posted February 26 And you'll be able to hear the air hissing out in the cylinders if, perish the thought, there's a leak there. Yes agreed. On an unknown engine that would most certainly be warranted. Since this was a running engine and the compression test was excellent and didn't overheat, I think it will be fine. The coolant was absolutely full when I got the donor truck and green as can be. They botched the water pump job but otherwise no concerns. My main goal was (Still is as I need to repeat) to establish a good intake manifold seal and also good water pump seal. Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 26 Share Posted February 26 Yes agreed. On an unknown engine that would most certainly be warranted. Since this was a running engine and the compression test was excellent and didn't overheat, I think it will be fine. The coolant was absolutely full when I got the donor truck and green as can be. They botched the water pump job but otherwise no concerns. My main goal was (Still is as I need to repeat) to establish a good intake manifold seal and also good water pump seal. And I think you did that. Link to comment Share on other sites More sharing options...
viven44 Posted February 26 Author Share Posted February 26 And I think you did that. Do you think what that thermostat housing leaking, if there were other issues it would have shown up in the preliminary test? Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 26 Share Posted February 26 Do you think what that thermostat housing leaking, if there were other issues it would have shown up in the preliminary test? If I understand the question correctly, yes I think any other problems would have shown up. But you can test by sealing that leak and going again - unless you are in a hurry. Link to comment Share on other sites More sharing options...
viven44 Posted February 26 Author Share Posted February 26 If I understand the question correctly, yes I think any other problems would have shown up. But you can test by sealing that leak and going again - unless you are in a hurry. OK good. At the beginning, the leak was very slow. My bad also because I did not fill the coolant all the way up. So the housing itself saw more air pressure, and caused the leak to grow more over time and it got pretty leaky fast. Second time around I'm going to use water all the way up and then re-test. Now that i'm saying it out aloud, I'm a bit worried about running an air test as it might be analogous to a "burn-in" test of water gaskets Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 26 Share Posted February 26 OK good. At the beginning, the leak was very slow. My bad also because I did not fill the coolant all the way up. So the housing itself saw more air pressure, and caused the leak to grow more over time and it got pretty leaky fast. Second time around I'm going to use water all the way up and then re-test. Now that i'm saying it out aloud, I'm a bit worried about running an air test as it might be analogous to a "burn-in" test of water gaskets Air doesn't give more pressure than water. It is just that I THINK water molecules are bigger than air molecules, but I don't know that for sure. Jim will know. Link to comment Share on other sites More sharing options...
viven44 Posted February 26 Author Share Posted February 26 Air doesn't give more pressure than water. It is just that I THINK water molecules are bigger than air molecules, but I don't know that for sure. Jim will know. Yes thats absolutely correct. The molecules are smaller, so they are able to find smaller passages, and once the flow gets going, it will eat through the passageway due to the momentum of airflow. Since I like analogies now In current carrying capability testing of materials, this is analogous to electromigration where the momentum of electron flow can knock atoms enough to cause voids in metals and an eventual "open". Edit: its a hypothesis, i don't want to make it sound like a fact Link to comment Share on other sites More sharing options...
Gary Lewis Posted February 26 Share Posted February 26 Yes thats absolutely correct. The molecules are smaller, so they are able to find smaller passages, and once the flow gets going, it will eat through the passageway due to the momentum of airflow. Since I like analogies now In current carrying capability testing of materials, this is analogous to electromigration where the momentum of electron flow can knock atoms enough to cause voids in metals and an eventual "open". Edit: its a hypothesis, i don't want to make it sound like a fact How much pressure are you using? At 15 psi like in a cooling system I don't think you'll have any damage save for a gasket that might leak. Link to comment Share on other sites More sharing options...
viven44 Posted February 26 Author Share Posted February 26 How much pressure are you using? At 15 psi like in a cooling system I don't think you'll have any damage save for a gasket that might leak. Yes I agree, a gasket leak is all that i'm talking about. Just thinking an air test will be ideal in an experimental setting if you are comparing different RTVs (like Project Farm below) but in this setting I am a little worried it may potentially weaken a gasket and set it up for a coolant leak. I don't have any empirical data except the coolant housing leaking from air-only... but just paranoid. I know 15 PSI is low and probably be fine Link to comment Share on other sites More sharing options...
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