What Hoses For A Closed To Open Cooling Swap

[87mjdriver]

alright I am doing a closed to open swap, I have the radiator but i don't know what hoses i need to get and whether or not to include a heater control valve, I heard the late model xj's did away with the valve completely (true?) last time i replaced the heater hose on my renix I remember on of the hoses was an odd ball had a 3/4 I.D. on one end and  a 1/2? on the other end.  can anyone help with part numbers or  maybe a picture

[Blue88Comanche]

I believe the heater valve can be bypassed as the cabin temperature is regulated with a flap in the dash.

[ParadiseMJ]

I've converted two Renix Jeeps to open and deleted the HCV on both with no ill effects.  I used the molded hose for a 97 on both as well.  I have to remember to ask for 92-96 cooling parts, except for the t-stat housing.  The 90 XJ has a 92 t-stat housing from the JY, the 88 has a new 88 t-stat housing.  The 90 XJ has a plug/petcock in the sensor hole (you won't need that sensor as it won't work for the e-fan).

 

Note:  The 88 housing allows for the t-stat to be installed backwards, FYI, the spring goes in the block.   The 88 housing is also a bit larger inside, other wise identical flange & bolt holes

[Rockfrog]

When I converted my MJ this summer I used stock 88 rad hoses, an '00 rad (spare from my XJ), and generic 5/8" heater hose. Heater hose was tight on one side and fine on the other. I ran two lines straight from heater core to thermo housing deleting the valve altogether.

[87mjdriver]

Ok so just get the 2 heater hoses for a 97+ xj and no valve, I already have the radiator hoses.

I'm trying go for a cleaner/neater look I the engine compartment, I think I might do the 97+ washer fluid bottle upgrade too

 

 

Paradisemj: can I retain the 87 thermo housing or do I need to get a newer one?

 

By the way thanks for the replies guys

[Rockfrog]

Here's mine

Heater hosing (stock '88 thermo housing) just used bulk 5/8" hose for both runs

Coolant recovery (I pulled the hose out so you could see it, usually it tucked away ... will be installing a '92 XJ bottle soon)

 

Hope that answers a few questions for you.

[ParadiseMJ]

What ever t-stat housing you have now will work.  I  replaced mine because the flange had a hairline crack in it.  The crack was visible on the outside, but I could not see it on the inside...so just to be safe I bought a new one for $12 or so.  It's shiny which is super important to me!!

[Exgrayxj]

On my LT1 Chevy powered xj Waggy, and again on the '90 mj, when I converted to open system, I used the original pressure tanks, just modified them to work.

 

Both had pressure split at the seam, so were NFG anyway.

 

I sawed the nipple off the bottom and the side, cleaned things up, and used a metal tubeless tire valve stem, did a little searching in my junk box.

 

Ran hose from radiator nipple along heater hoses to bottom of tank. Zip ties.

 

There is no pressure there now, so no pressure to make the cracked tank leak..

 

Gutted the screw on cap. Simple.  Screwed a countersunk pipe plug into the top(side) port.

 

After things equalize, you will find that the level varies hardly at all, I usually run with only about an inch or so of coolant in the tank, and things seem to be working fine ... tank remains in stock location, and I didn't have to buy more parts or find new location.

 

Don't forget a new rad cap.

[carnuck]

'91 rad and all heater hoses works fine. I put a "universal" vacuum heater switch on. Aside from taking a few minutes running to engage, it's fine.