What material is used for coolant lines for a rear radiator?

Area for Offroad Modification Tech
Post Reply

Topic author
AwesomeJ10
Posts: 3031
Joined: Sat Aug 27, 2011 10:26 am
Location: Off the grid on Storm Mountain Colorado
Contact:

What material is used for coolant lines for a rear radiator?

Post by AwesomeJ10 »

I am swapping a GM 8.1l engine into the honcho :D and I am planning to run a rear radiator in an effort to keep it cool.

What is the best material to use for the coolant lines that is reasonable in cost? I'm seeing on pirate that everyone is using anything from DOM, to aluminum, to EMT, to pipe and even rubber hose.

Thoughts? Whatever I use, must be very reliable...
User avatar

Tatsadasayago
Posts: 3684
Joined: Thu Aug 28, 2014 2:22 pm
Location: Sacramento, CA

Re: What material is used for coolant lines for a rear radiator?

Post by Tatsadasayago »

In my younger days I ran around with Rod Hall's son Chad. I got to see quite a few of his dad's SCORE/BAJA pickups being built in their shop. Rod used 1-1/2" rigid copper plumbing pipe and sweat fittings for the rear radiator and it seemed to work great. The connection to the engine and rad were rubber hose which prevented electrolysis stripping of the copper by the cast iron engine block. This nice thing about copper pipe is you only need a torch, flux and solder to repair a leak out on the trail as opposed to trying to plug weld steel or plug aluminum or rubber.
I've seen 3/4" rolled soft copper tubing employed in the under seat school bus heaters back in the day. The tubing ran along the underside of the floor and was secured by rubber coated U-clamps.
1977 Cherokee Chief - The Blair Jeep Project III
A collection of parts flying in close formation

Topic author
AwesomeJ10
Posts: 3031
Joined: Sat Aug 27, 2011 10:26 am
Location: Off the grid on Storm Mountain Colorado
Contact:

Re: What material is used for coolant lines for a rear radiator?

Post by AwesomeJ10 »

well I don't carry a torch on the trail. But I do carry gorilla tape and at least one gallon of antifreeze. Guess if I went this route, I'd have to carry a torch and stuff on the long trips to Moab, dunes, Ouray, etc.
User avatar

Tatsadasayago
Posts: 3684
Joined: Thu Aug 28, 2014 2:22 pm
Location: Sacramento, CA

Re: What material is used for coolant lines for a rear radiator?

Post by Tatsadasayago »

I started carrying a MAP gas torch after struggling to remove the tapered axle nut on a CJ-7 that had sheared the keyway while up on the Rubicon.
I think if I was going to do the rear rad setup, I'd use the heavy rubber hose used on Class A trucks which would likely outlast the rig.
1977 Cherokee Chief - The Blair Jeep Project III
A collection of parts flying in close formation
User avatar

Stuka
Site Admin
Posts: 11789
Joined: Thu May 12, 2011 5:53 pm
Location: CA
Contact:

Re: What material is used for coolant lines for a rear radiator?

Post by Stuka »

Most buggies and baja racers and such run the coolant through the cage tubing.

I would not use rubber for the full length. Make the main length out of rigid tubing (material of your choice). Steel would be my guess, then run shorter rubber hoses between the rad and rigid tubing.
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

SJTD
Posts: 1924
Joined: Tue May 21, 2013 12:02 pm
Location: Lompoc, Sunland or somewhere between

Re: What material is used for coolant lines for a rear radiator?

Post by SJTD »

Tatsadasayago wrote: The connection to the engine and rad were rubber hose which prevented electrolysis stripping of the copper by the cast iron engine block.
I think someone was overthinking this. You'd want that connection to have some give for vibration and the frame flexing. Same at the radiator. At least that's why I'd use the hose.

Also, iron is sacrificial to copper. It's the one that would corrode.
Sic friatur crustulum

'84 GW with Nissan SD33T, early Chev NV4500, 300, narrowed Ford reverse 44, narrowed Ford 60, SOA/reversed shackle in fornt, lowered mount/flipped shackle in rear.
User avatar

Tatsadasayago
Posts: 3684
Joined: Thu Aug 28, 2014 2:22 pm
Location: Sacramento, CA

Re: What material is used for coolant lines for a rear radiator?

Post by Tatsadasayago »

You're quite right, I had it backward.
1977 Cherokee Chief - The Blair Jeep Project III
A collection of parts flying in close formation
User avatar

carnuck
Posts: 3881
Joined: Sun Mar 04, 2012 2:48 pm
Location: Lynnwood, WA
Contact:

Re: What material is used for coolant lines for a rear radiator?

Post by carnuck »

Rear rad only? If you ran dual rads I would use 1" copper tube and have shut offs in case one or the other sprung a leak. Especially desert driving. We packed 5 gallons of drinking water (and 3 days food) so that if we were stuck in nowheresville, we'd be fine and a major leak could be fed to get us back to the highway. I thought about filling the front bumper with backup mixed radiator fluid. Heck, I even considered plumbing the tube front bumper to the rad for extra cooling.
Check my parts for sale near Seattle
User avatar

Cecil14
Posts: 727
Joined: Mon Oct 01, 2012 6:40 am

Re: What material is used for coolant lines for a rear radiator?

Post by Cecil14 »

Copper would be a dual-edged sword; a nice long run to the back would help dissipate a good deal of heat in addition to the rads, however it's going to get pretty warm as well so you'd want to tuck it up somewhere.


aa
1983 J-10 - 4.6L(MPFI)/CS130D/Hydroboost/NV3550/D300/44/44/3.54/Disc-Disc/32s/42 gallon 'burb tank

Topic author
AwesomeJ10
Posts: 3031
Joined: Sat Aug 27, 2011 10:26 am
Location: Off the grid on Storm Mountain Colorado
Contact:

Re: What material is used for coolant lines for a rear radiator?

Post by AwesomeJ10 »

I think I'm gonna end up running 1 3/4" roll cage tube for the water lines. Only thrbrear radiator as I'm kinda curious how that works and I would like to move as much weight as possible to the rear.
User avatar

tgreese
Posts: 7118
Joined: Fri Jun 08, 2012 6:31 am
Location: Medford MA USA

Re: What material is used for coolant lines for a rear radiator?

Post by tgreese »

The main problem with copper over steel is that copper work hardens, and steel does not. So if there is any flex in the copper lines, they will crack eventually. If you put enough flex couplings in the run, I would not expect this to be a problem. The main advantage is you can get dozens of different types and sizes of copper pipe and fittings, and they are easy to solder together to get the shape you want.

It's think the premium solution would thin-walled steel or stainless tubing. TIG weld it together, and join it with short lengths of flexible rubber tubing.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
Post Reply