Originally Posted by Bustedback

I'v never done the swap, but there are many that have on this forum. I'm sure somebody will share the needed info.

Originally Posted by Illuminator

I'm about to replace my radiator and was wondering if it's worth the extra money and work to convert to a open cooling system.

Originally Posted by Vstahl

I did it one mine, best thing for cooling in my opinion. You will need a new radiator, overflow bottle, and some heater hose is about it if I remember right. Wasn't really anything out the normal especially since you are planning a new radiator anyway.

Originally Posted by 5-90

I honestly don't think so - out of the five RENIX rigs I've had, the one that ran hottest had been converted when I bought it, and maintenance on the "closed" system is no more difficult than on the "open" system.

Get a quality aftermarket radiator (I usually use Modine, but reports from the field on the CSF have also been good) that is ALL METAL, and you'll be fine. (Yes, even the Jeep wrenches say to get aftermarket - the OEM ones tend to have tube clogs around 150-180Kmiles. Aftermarket units can put miles on like you can't believe - I've got a Modine still in service with somewhere north of 200Kmiles on it now, with no trouble.

The only real headache is filling the system - which is still easy to deal with. Look up my posts on drilling the thermostat to deal with that - drilling allows air to pass out from behind the thermostat and be displaced with coolant, which then allows the thermostat to function properly.

The only real "problem" I can see with the "closed" system is the somewaht flimsy plastic tank up near the firewall - keep it regularly replaced (every five years seems to be about right - change it and the fan clutch at the same time)
and you'll be alright.



Alternatively, you can get a metal unit that takes a standard radiator cap - I think the outfit that makes tham is called "Mac's" something-or-other, but they're spendy. Probably well worth it tho - they're aluminum, so they won't rust out on you. (I'd prefer copper or brass, but that's just me.)

Originally Posted by Caish

My only complaint with the renix cooling system is I can't get heat from it in less than hour in the winter time.

Originally Posted by Bustedknuckle

All mine did was over heat. Converted with a jy setup, one of the best things I've ever done, couldn't be more pleased.

Originally Posted by Illuminator

Anybody know if the open system heats up faster, currently my heater core is disconnected, thats also on the fixit list.

Originally Posted by 5-90

No faster, no slower.

The only odd time I have is on my 88 - which doesn't like running with any thermostat at all (no, I can't figure it out either. But, whenever I try to put a thermostat in, it will ht 240-260*F within ten minutes, no matter what I do to try to prevent it. I've overhauled the entire cooling system, including the heater core, so I know that's not it. I know it's flushed out, because I did that.

(Oddly, when I remove the thermostat and run without it, it runs just fine. It doesn't overheat, I've pulled the operating temperature down to about 190-195*F on hot days, and it doesn't heat up any faster or slower than normal - which is why it's an oddity. I can't figure it.

(It's the third vehicle I've had that acted that way - the other two were a 1980 Honda Accord with the 1800c/c CVCC, and a 1985 Cavalier with the V6-171. More or less the same results, definitely the same Sx and treatment, although the Chevvy did take about half again as long to heat up as a comparable vehicle. The Honda was just fine.

(Definitely one of the odder things I've run across in thirty years of swinging wrenches!)