Air in 914 V8 cooling system, Need advise.... Options

[boxstr]

Today after installing front Konis on the V8 914 , started the car and the water pump hose clamp was loose so it puked out a fair amount of coolant. Added a 50/50 mix. ran the car until warmup and drove the car, cold and rainy weather, so it didn't really get hot. @ 160-170.
Any suggestions that I should do as far purging out any air that might be in the system. Or maybe I don't need to do anything.
TIA
CCLINV8CANTWAIT

[John2kx]

Craig,

Anytime air is allowed into system this is how I remove it:

Ensure car is completely cool. Open fill port and add water until almost full (about 1/2" from top to allow for small amount of expansion). Start engine and leave cap off at fill port. Have water available to add if necessary. What your doing here is allowing any air bubbles/pockets to work their way to high point (fill point) of system and escape while water is circulating throughout cooling system.

In about 2-4 minutes your engine temp. will begin to rise and water expansion will occur. Watch opening in fill port and you'll see the air bubbles work their way to this point and release to atmosphere. You'll want to have radiator cap handy to install before it starts pouring out of fill port. One other thing you can do to allow car to run just a little longer with system open is increase idle to about 1200-1500.........this will drop water level at fill port while allowing you to run engine just a little longer and remove additional air pockets. Note: have radiator cap in one hand and install as water expands to top of fill port.......do not allow idle to drop off before installing radiator cap or you'll have a mess on your hands.

Take car out for a drive and allow to get to operating temperature. Turn engine off and allow to cool to about 170F. At this point, crack petcock at radiator and allow water/air to escape until a steady stream of water is present.

Do the second part of this procedure (drive and purge) one more time and you should be good to go. You know what your water gage/temps. looked like prior to this and if you see anything abnormal, (spiking or high water temperature readings) you know there is still air in system.

One other thing here Craig. I've heard of several folks actually blowing hose off at inlet of water pump. This happens while engine is cool at startup and is caused due to water pump dead head heading while thermostat is fully closed. This is where the one to three 1/8" holes in thermostat come into play. They prevent the pressure buildup at inlet hose to water pump prior to t/s opening. The holes also allow air to escape during the procedure I mentioned above. Without these holes, the procedure I mention above will not work since your not "recirculating" water and allowing air to escape at fill port while t/s is closed. These holes are what speed up the bleeding process. You can remove air by simply cracking open petcock as described above..........it will just take longer since the majority of air is actually removed while fill port is open.

If you are unsure weather you have the modified t/s (1/8" holes), open fill port and start engine. If you see no flow of water here, you don't have holes in t/s and will not create the needed flow until engine temperature approaches 140F or so. You will also notice water expansion at a rate that will prevent fill port to be open for more than just a few minutes.......in other words, it will begin to overflow at a uncontrolable rate due to expansion during the heatup process.

BTDT lesson learned: never turn engine off during the warm up period with fill port open. This will create the biggest mess you've ever seen in engine bay as about 1/3 of your coolant pukes out of fill port...........don't ask : )

John