Cooling System Air Lock?

Any guesses on which hydro dynamic principle I am missing on my deal... Pretty standard set up, CSR water pump, Inline rad cap is the highest point in the system. This thing air locks really bad when filling with water. Giant PITA....

dkp

(A) Maybe use a little WaterWetter to reduce the water's surface tension.

(B) Have someone repeatedly turn the water pump on/off as you fill it with water.

(C) If it's a low slung big tire full chassis car with the engine sitting in the chassis crank-nose down, it might sometimes be hard to chase out air/steam pockets trapped at the back of the heads. If so try jacking the front of the car up a little when filling it with water to help any possible trapped air/steam pockets at the back of the heads work their way to the front of the engine & towards the in-line filler neck.

This might be worth trying. I had that problem when my Mustang was my daily driver and it was time to change out the anti-freeze. I made up two fitting and installed in the system. One for a constant water supply and the other to pull a vacuum. Using my brake bleeding canister, I would pull some vacuum and introduce the water until I saw no more air bubbles in the line. Just like you would do when doing a one man brake bleed. Problem solved!

For about 10 years or so I had a VW Fox as a daily driver car back and forth to work. I put a timing belt on it a couple of times, a water pump and a hose or two. That car was IMPOSSIBLE to fill with water. I used to mess around trying to get it full and I never could until I figured out the secret. Put in as much water as you can then start the engine with it running pour in the coolant.

In that system the jug is pressurized and has a hose out the bottom that goes to where the lower hose connects to the water pump. It also has a small line that comes from the thermostat housing on the head. With it running I just poured in the water until steady water came out of the little hose and it was full every time. I wonder if you could do something similar?

thx guys... good thoughts.

I appreciate your time..

dkp

IF running a thermostat, I always put a 3/32 or so hole in the flat flange of the thermostat to make for a constant bleed, and as said above fill while running.

All good points, I use the washer no thermostat, top it up, then I run the car with water pump running and top up with a bucket under the catch can, when it starts to splash out of the filler i put the cap back on and let it run till operating temps are reached and open the drain for the catch can... it is streeted with water and water wetter an usually sits at 180 occasionally briefly reaching 190-200 after a pass and cools right back to 180^

Thx for the input guys... this is on my A460 block race motor with aluminum C460 heads. Electric pump, small rad, no thermostat. not a lot of airflow under the hood. when I try to fill it with the pump off it stops after a gallon or so goes in.. starts overflowing out the cap. so start the pump. big surge of flow then nothing... pump goes dry. Add more water with pump running very quickly starts to overflow. if I wait for air bubbles to come out it will very slowly start to go down but water doesn't circulate. after about 10 minutes of dribbling water in the pump finally picks up the prime and starts to move water around... I think I am going to eliminate the inline upper rad hose rad cap and try the expansion tank type system...

Is it worth plumbing bleeder lines in to the back of the intake manifold?

dkp

bosshoss wrote:Thx for the input guys... this is on my A460 block race motor with aluminum C460 heads. Electric pump, small rad, no thermostat. not a lot of airflow under the hood. when I try to fill it with the pump off it stops after a gallon or so goes in..   starts overflowing out the cap. so start the pump. big surge of flow then nothing...  pump goes dry. Add more water with pump running very quickly starts to overflow. if I wait for air bubbles to come out it will very slowly start to go down but water doesn't circulate. after about 10 minutes of dribbling water in the pump finally picks up the prime and starts to move water around...   I think I am going to eliminate the inline upper rad hose rad cap and try the expansion tank type system...

Is it worth plumbing bleeder lines in to the back of the intake manifold?

dkp

I don't think they will be helpful if the engine sits in the car close to normal with the front up by a few degrees.  On a 383 Cleveland that I built for one of my customers with a Pantera he was always worried about trapping air in the back of the heads because the engine sits level in the car.  He had experimented with drilling the corner of the heads and installing petcocks but on my build I drilled the corner of the head and put in a couple of small AN lines which T'ed together into a single line which ran over the top of the engine and then down to the suction side of the water pump.  In that fitting I put about a .060 orifice just to allow a small amount of water and any residual air to escape and not accumulate in the heads.  After quite a few open road events it has worked very well.

Here is a picture of the Cleveland in the Pantera:

DaveMcLain wrote:

bosshoss wrote:Thx for the input guys... this is on my A460 block race motor with aluminum C460 heads. Electric pump, small rad, no thermostat. not a lot of airflow under the hood. when I try to fill it with the pump off it stops after a gallon or so goes in..   starts overflowing out the cap. so start the pump. big surge of flow then nothing...  pump goes dry. Add more water with pump running very quickly starts to overflow. if I wait for air bubbles to come out it will very slowly start to go down but water doesn't circulate. after about 10 minutes of dribbling water in the pump finally picks up the prime and starts to move water around...   I think I am going to eliminate the inline upper rad hose rad cap and try the expansion tank type system...

Is it worth plumbing bleeder lines in to the back of the intake manifold?

dkp

I don't think they will be helpful if the engine sits in the car close to normal with the front up by a few degrees.  On a 383 Cleveland that I built for one of my customers with a Pantera he was always worried about trapping air in the back of the heads because the engine sits level in the car.  He had experimented with drilling the corner of the heads and installing petcocks but on my build I drilled the corner of the head and put in a couple of small AN lines which T'ed together into a single line which ran over the top of the engine and then down to the suction side of the water pump.  In that fitting I put about a .060 orifice just to allow a small amount of water and any residual air to escape and not accumulate in the heads.  After quite a few open road events it has worked very well.

Here is a picture of the Cleveland in the Pantera:

IIRC back in ancient times Paul Bedoian of Pro Stock Engineering offered some kind of steam pocket bleed-off/cross-over tubing kit for FE's that was threaded into the rear of either the intake or the heads.