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Blower Cooling System - Adding Air Capture and Bleed Points
So, I am trying to get a better grasp on this system and where the air is coming from and where the air is ending up.
Since I have a stock lt4 blower and blower bricks, and want to keep my warranty, I am not going to pursue the idea of trying to port into the cooling bricks to allow a hard line to come out to an external tank to gather air that can then be bled off.
instead, im going to keep it simple, and just add T's and rubber hose that dead end into a bleed port fitting, throughout the system in different spots.
In this video, I show 1 location that I will put a T and a hose, but after I was done recording, I soon realized, it would be a simple task to add a few other T's and vertical hoses about 6 inches tall, around the system at different points. So, between the pump and the intercooler, and between those and the stock res tank, etc.
And then, all at the same time, after a week or 2, check them all, and try to be scientific about it, and figure out which one gathers the most air, and perhaps that will allow us to determine where the air is coming from. I also think one of these T's right next to the pump... will be a great location, as the cavitation bubbles that gather in the pump, would then hopefully find their way up the hose, next to the pump at that T.
I also thought about the idea, on my next vehicle, of adding a second water pump to the system... this would allow for the first one to be shut off, and the second one still run, and clear the cavitation out of the first, and they alternate shutting off on a random timer, where they each only shut off for 3 to 5 seconds, and then they are both on together the rest of the time, and they go back and forth, and I would disable the factory setup where the pumps shut off for 3 minutes at a time, which is a long time and its pretty much insanity... if you stop and think about it.
Some guys have managed to melt cooling bricks in the blower, or bust them somehow, but it has to do with the heat generated by the blower not being carried away, since the fluid just sits, since the pump being off for 3 min at a time.
My res tank has gathered air. Air could also be up in the bricks and other places in the system. Not sure how or why the system produces air, so thinking of adding T's with dead end hoses pointed vertically in different locations around the system to try to capture the air to be bled off routinely.
2 possibilities I can see for air getting in are
1. The filler cap by the Blower
2. The back side of the water pump's blades, easily creating cavitation in already hot water, as propellers boil water in a somewhat mysterious phenomenon (guys who own race boats know what it does to our props)
if anyone can point me towards the cheapest most effective T's i could use on these lines, as well as the best way to plug the hose and have a bleeder valve on the end, much appreciated.
Interesting ideas. I wonder if degassing all the coolant, prior to filling an emptied system, would be of any benefit? Applying a vacuum to the already-filled system should do some degassing, but would also lead to some of the released gas being trapped at higher points in the system.
I thought the highest point is the filler neck and those hoses. And the bricks are actually lower than the fill cap by a very small margin. I can’t believe GM would miss something that basic. Thanks
My res tank has gathered air. Air could also be up in the bricks and other places in the system. Not sure how or why the system produces air, so thinking of adding T's with dead end hoses pointed vertically in different locations around the system to try to capture the air to be bled off routinely.
2 possibilities I can see for air getting in are
1. The filler cap by the Blower
2. The back side of the water pump's blades, easily creating cavitation in already hot water, as propellers boil water in a somewhat mysterious phenomenon (guys who own race boats know what it does to our props)
My res Tank as of 7/21/18:
My res tank after purging it, 7/12/18:
Quick ?, That is exactly how my tank looks as of yesterday. How did you purge air out?
Thanks
I thought the highest point is the filler neck and those hoses. And the bricks are actually lower than the fill cap by a very small margin. I can’t believe GM would miss something that basic. Thanks
It MAY vary between 15-16 and 17-19 model year blowers, im not sure, but, the problem is the fluid passages go lower as they exit the blower out the stock purge and fill line, so the air stays trapped UP HIGH in the bricks, it has no reason to "come down" even when we pull vacuum on the system. Either way, I want to catch the air as it moves about, and see if i can keep air from ever developing around the pump, if i get the system so well purged.
Originally Posted by Warp Factor
Interesting ideas. I wonder if degassing all the coolant, prior to filling an emptied system, would be of any benefit? Applying a vacuum to the already-filled system should do some degassing, but would also lead to some of the released gas being trapped at higher points in the system.
I figure if a couple of those T's are around, it would catch the air as it goes by anyway. Adding T's into the stock system will add length... i realze down low, between the pumps and the front intercooler, the T will be laid diagonal, so that the stock hoses each angle up to the 90 degree of the T, and the straight path across the TOP OF THE T, if you will, will go to the dead end, which will be pointed diagonally UP... that way the fluid has to do a 90 degree turn as it flows, and hopefully more air goes straight and up the dead end hose, when the fluid takes a 90 degree turn.
Another cool thing about the dead end hoses is one can experiment with keeping the system under slight vac, just by squeezing these hoses to bleed them, and then sealing off the bleeders while the dead end hoses are still squeezed and collapsed. Now they have room to expand as time goes on and air is made.
However, vac only allows fluid to boil easier, so im not sure that is going to be of any benefit... but still wanted to point out the possibilities.
Does anyone have an idea what the most cost effective way to add bleeder valves and block off the end of these hoses will be?
Maybe ordinary tire valves? Although I'm not sure how much vacuum they would hold if you vacuum-bleed the system.
so then next stupid question... how would I dead end and attach the black hose that dead ends to those valves? I will look into it, but would rather save the time if someone else knows quickly.
I think i would rather have bleeders like the brass ones up top so I can just open them, squeeze the hose or gravity fill the system with the big hose on the fill port... so if anyone has an idea for those, I think that would be ideal
i found a radiator drain valve at autozone or whatever store i was at. It is threaded, and about a half inch in diameter at the threads. It would be ideal if it was barbed, but since the system is not really pressurized much, i am pretty confident that a hose clamp around the threads and maybe some thread tape on there, will make it seal up fine.
It was pouring rain outside, so i grabbed the hose i thought was the right size, 1/2 inch, but once i got home i realized the hose on the car is more like 5/8 inch, it doesn't say the size on the hose, so i went in with just a photo with my finger next to the hose for reference... but i think i can make it work... or ill just buy some 5/8 tomorrow while im out. I also went to home depot to buy the metal barbed T, and that was a fail. I'll have to find the barbed T tomorrow at my local hydraulic shop.
My res tank has gathered air. Air could also be up in the bricks and other places in the system. Not sure how or why the system produces air, so thinking of adding T's with dead end hoses pointed vertically in different locations around the system to try to capture the air to be bled off routinely.
2 possibilities I can see for air getting in are
1. The filler cap by the Blower
2. The back side of the water pump's blades, easily creating cavitation in already hot water, as propellers boil water in a somewhat mysterious phenomenon (guys who own race boats know what it does to our props)
So, I am trying to get a better grasp on this system and where the air is coming from and where the air is ending up.
Since I have a stock lt4 blower and blower bricks, and want to keep my warranty, I am not going to pursue the idea of trying to port into the cooling bricks to allow a hard line to come out to an external tank to gather air that can then be bled off.
instead, im going to keep it simple, and just add T's and rubber hose that dead end into a bleed port fitting, throughout the system in different spots.
In this video, I show 1 location that I will put a T and a hose, but after I was done recording, I soon realized, it would be a simple task to add a few other T's and vertical hoses about 6 inches tall, around the system at different points. So, between the pump and the intercooler, and between those and the stock res tank, etc.
And then, all at the same time, after a week or 2, check them all, and try to be scientific about it, and figure out which one gathers the most air, and perhaps that will allow us to determine where the air is coming from. I also think one of these T's right next to the pump... will be a great location, as the cavitation bubbles that gather in the pump, would then hopefully find their way up the hose, next to the pump at that T.
I also thought about the idea, on my next vehicle, of adding a second water pump to the system... this would allow for the first one to be shut off, and the second one still run, and clear the cavitation out of the first, and they alternate shutting off on a random timer, where they each only shut off for 3 to 5 seconds, and then they are both on together the rest of the time, and they go back and forth, and I would disable the factory setup where the pumps shut off for 3 minutes at a time, which is a long time and its pretty much insanity... if you stop and think about it.
Some guys have managed to melt cooling bricks in the blower, or bust them somehow, but it has to do with the heat generated by the blower not being carried away, since the fluid just sits, since the pump being off for 3 min at a time.
Shouldn't there be a little air space in the intercooler tank to allow for fluid expansion? There is no overflow tank like on the engine cooling system.
The underlying problem is cavitation in the pump and its partly caused by having the inter-cooler core between the tank and the pump inlet causing friction loss leading to low pressure at the pump inlet and cavitation across the pump. This causes bubbles to form and they do not collapse easily back into the fluid.
So bleed to your hearts content but the bubbles will form and the tank will show a small pocket at the top again. That pocket of vapor in the tank is NOT the problem, it never gets to the bottom of the tank. The cavitation across the pump still happens and the pump shuts down. The system is poorly designed with components in the WRONG order.
I'm not defending GM but, that car has sensors for everything. How can there not be one for that important of a system? I run my car down 27 in Miami at 150 for miles all the time and never had any problems with anything. Aren't both feed and return lines on the driver side of the intercooler and the tank is plumbed into the passenger side of the intercooler as an expansion tank? I would like to see a schematic because I cannot figure how the pump would be starved for fluid and then heat up and shut down. I'm sure engineers from all car companies have looked at this set up, GM would be laughed into having to redesign. I'm an aircraft mechanic, I know almost nothing about this. It's hard to follow the flow of everything because I cannot see it.
The car does have sensors, it does know when the pump is in cavitation, and it does shut off the pump for 3 min and this is the problem. The intercooler overheats within the blower.
I am well aware of adding aftermarket tanks etc, and changing the flow pattern. This also voids the warranty on the vehicle, so please don't pretend there is not a negative trade-off, in addition to the thousands of dollars one must spend on GSpeed equipment, etc.
All that being said, in my first posts, I go on to say that adding another pump, for a total of 2 water pumps in the system, would greatly reduce cavitation, and when cavitation does occur, instead of either pump being shut off for 3 minutes, all one has to do is shut it off for 5 seconds or more, and the flow of the other pump will cause the bubbles to be washed away from the blow that is shut off, and they take turns shutting off, each for 5 seconds or longer, but the entire time the system has flow, so the blower no longer overheats.
In the meantime, I want to see IF getting all of the air out of the system, CAN eliminate cavitation, or to what degree it can be reduced to.
Shouldn't there be a little air space in the intercooler tank to allow for fluid expansion? There is no overflow tank like on the engine cooling system.
I would rather it expand into the dead end hose, and have the air there... than have air in the system loop that can get back to the pump again.
I'm not defending GM but, that car has sensors for everything. How can there not be one for that important of a system? I run my car down 27 in Miami at 150 for miles all the time and never had any problems with anything. Aren't both feed and return lines on the driver side of the intercooler and the tank is plumbed into the passenger side of the intercooler as an expansion tank? I would like to see a schematic because I cannot figure how the pump would be starved for fluid and then heat up and shut down. I'm sure engineers from all car companies have looked at this set up, GM would be laughed into having to redesign. I'm an aircraft mechanic, I know almost nothing about this. It's hard to follow the flow of everything because I cannot see it.
Diagram in Post 11 shows how the system is plumbed.
The car does have sensors, it does know when the pump is in cavitation, and it does shut off the pump for 3 min and this is the problem. The intercooler overheats within the blower.
I am well aware of adding aftermarket tanks etc, and changing the flow pattern. This also voids the warranty on the vehicle, so please don't pretend there is not a negative trade-off, in addition to the thousands of dollars one must spend on GSpeed equipment, etc.
All that being said, in my first posts, I go on to say that adding 2 pumps in the system, would greatly reduce cavitation, and when cavitation does occur, instead of either pump being shut off for 3 minutes, all one has to do is shut it off for 5 seconds or more, and the flow of the other pump will cause the bubbles to be washed away from the blow that is shut off, and they take turns shutting off, each for 5 seconds or longer, but the entire time the system has flow, so the blower no longer overheats.
In the meantime, I want to see IF getting all of the air out of the system, CAN eliminate cavitation.
Correction. The PUMP has a cavitation sensing and shuts down. The Car's ECU has no idea.
07-22-2018, 01:56 AM
Blower Cooling System - Adding Air Capture and Bleed Points
