Closed to Open Cooling System Conversion

[anthony]

thanks cw .. that is great info/tech sir

[Jeepncreepn]

mine doesn't lose any coolant at all. I don't understand your question. some punctuation might help. :dunno:

if it dosent lose coolant at the rad neck overflow nipple, what rad cap did you use?

[Pete M]

16 pounder.

 

what was the problem with the system before you swapped in the new radiator?

[Jeepncreepn]

16 pounder.

 

what was the problem with the system before you swapped in the new radiator?

 

no problem realy, just had the original single core rad in it, and a friend gave me one out of a 95 xj he parted that had the filler neck and was a dual core.

 

i had to use a bolt and small piece of hose and clamp it to the overflow nipple on the rad itsself

[360MJDude]

I've done this with a couple of my buddies Jeeps.

 

Ordered a inline radiator water filler neck from Summit racing (SME-xxxx 1.25 in/out) and placed it above the a/c compressor so it makes it the highest point and added a universal overflow from the parts store and some 3/8 heater hose.

 

Depending on the filler neck you could do it for less than $50.00

[comanche09]

16 pounder.

 

what was the problem with the system before you swapped in the new radiator?

 

I'm running an 18 pounder radiator cap on my converted open system, any problems/benefits with this? Thanks

[Pete M]

not really. by the time it overheats enough to blow, it'll likely blow any cap. :D His question was specific to retaining the closed system after swapping in a radiator with a cap.

[75sv1]

Just a few comments, the thermostat housing spacer is for the use of a valve cover spacer, that is needed if you use MOPAR roller rockers. See a "Comanche Named Sue". I think there was a write up on Cherokee America on this type of radiator swap, also I think MADXJ. There was a link on the CA site to someone who wired up the tempswitch for the fan and stuff. If you don't find it, I might have a hard copy of it. I'd have to search though.

I have heard the late model '97+ radiators have a better heat tranfer than the earlier radiators. I don't know that for a fact though. I did buy a 3 row DSG raditor myself. I do like the Mr. Gasket/Robert Shaw Hi-Flow thermostats. I would caution the use of the 180 F thermostats in cold weather. It might not let your temps get hot enough. I think they and the 160 F were mainly for the early Fuel Injected cars and drag racing. For a run or two, the computer would notice a cooler motor and dump in more fuel. A bit better ET time. In cold weather your oil might not warm up enough to cook of the water. Not good for dino oil.

Now for the closed-loop radiator system. Even though I am converting to an open system on my Comanche, my Ford Contour uses a closed system. I lot of newer cars do. Also, older Mercedes Benzs had it back in the early 80's. I hope/plan to convert my 240d to a closed loop system like the 300D's or 300TD's.

Good write up though.

Tom

[Waytec]

What did you do with the thermo switch? the new rad had no place for it.

[1989 Eliminator]

So its time for me to change out my radiator because I'm pretty sure its plugged. And converting to an open system to me seems like a better idea... A couple questions.

 

First off i have a 1989 4.0L

 

Can i use the stock heater control valve?

Do i need to buy new hoses?

 

[codymanche]

can you redue the pics they didnt come up/

[ajohnson928]

:agree:   I've got a crack forming in my closed system pressure bottle.  Something is going to have to be done soon but the radiator appears to be in good shape for now.  What do you all think: try to find a pressure bottle in good shape or do the conversion to an open system?

[zackcj7]

:agree:   I've got a crack forming in my closed system pressure bottle.  Something is going to have to be done soon but the radiator appears to be in good shape for now.  What do you all think: try to find a pressure bottle in good shape or do the conversion to an open system?

 I just bought a new pressure bottle last week from partsgeek.com for $22.

[ajohnson928]

Well that answers that question.  I'm heading there now.... :typing:

[91Pioneer]

I don't think anyone clearly explained the benefits of switching to an open cooling system. I've got a stock 88 with the closed system. I replaced the cap on the pressure bottle with the upgraded Stant 10244 cap and now my cap doesn't leak. The bottle has a slight crack but doesn't leak, and a new bottle is only $25 on Amazon. I don't see the justification in spending $600 on something that isn't broken. I'm not trying to start something, I just really want to understand what the benefits are. I don't care if my system is open or closed as long as it works :thumbsup:

[Rockfrog]

In my case it was done as the rad, bottle and valve/hoses all had to be replaced ... and I had 90% of thebparts leftover from redoing my XJ.

No benefit from it if it all works good.

My radvwas literally crumbling away and the bottle was cracked in several places ... it oozed coolant.

[ajohnson928]

Mine was in the same condition as Rockfrog's.  It was still rolling with the original 1989 radiator...or what was left of it.

 

I did the conversion in about 4 hours last Saturday with new radiator, overflow bottle, thermostat, rad hoses and heater hoses.  I deleted the heater valve.  Using all Autozone parts, the total was right at $250, so it's not a super expensive or time consuming project.