How to convert closed system to open system?

[kcclark]

I have an 86 xj with a closed system radiator I have an open radiator what is the best way to convert the system

[Slip Kid]

All I did was replace the radiator and get a heater control valve from an open system. All I had to do was make all the hoses fit.

[lawsoncl]

If you've got a radiator with a cap on it, just eliminate the plastic surge tank by plumbing directly to the heater core. You can either ditch the heater control valve or replace it. There is a neglible difference without the valve and it'll help keep the heater core from plugging up as bad. You'll need some sort of overflow bottle.

[winterbeater]

Don't need heater control valve. Run heater core direct and add a standard overfow bottle. For cheap, you could even adapt in an old antifreeze bottle.