I've seen at least 6-8 different approaches used in installing air separators in v8 conversions. The "in line" fill port mounted high in engine bay appears to be installed as a method of removing air and what I used in my installation with a expansion tank. This is the method recommended to me by Renegade and the fill port used was purchased from them.
BigKat83 (Bob) has a different approach at removing air and it works great for him. It requires more pieces/plumbing and appears to be a better mouse trap. He and I used to run our cars together and neither suffered from cooling problems. His setup is much easier to remove air from system if ever breached or upon initial fill.
Which is better? I'm not sure and think many factors can cause cooling problems with the v8s in our application. You may have a less than adequate radiator or fans, flow problems caused by improper hose size, insufficent burping of system, incorrect timing, lean fuel mixture, and the list goes on as to the cause of overheating issues.
There also seems to be different methods or locations as to where air should be removed i.e., engine bay or front trunk.
This would seem to be a simple problem to solve with so many water cooled cars on the road, but our configuration complicates things and does push a cooling system beyond its capabilities if not properly installed.
I'd suggest installing a simple fill port and overflow tank to start with. If that does not work, you could change your design and add a swirl pot, expansion tank, overflow tank etc..
There is some good info on this thread as well.
http://www.914world.com/bbs2/index.php?act=...2&t=35807&st=40I'm sure you have seen my setup. This one belongs to Bob.
John