Since there is WAY to much chit chat fluff in here, I thought we needed another solid tech thread.

Many of us delving into the deep stuff relocate our radiators into the rear. There are several different approaches; this thread is to talk about them. You can find how I did mine here: http://www.pirate4x4.com/forum/showthread.php?t=603541&highlight=radiator

Figured now that we have a mud forum it was time to drag it out of the depths of the Ford forum.

Discuss :D

this is a great idea. But is it worth doing on a street legal trail rig that only sees bumper deep mudwith 4" lift and 37's?

this is a great idea. But is it worth doing on a street legal trail rig that only sees bumper deep mudwith 4" lift and 37's?

For street legal, maybe not. If you mostly use it in the mud, then yes. Just because the mud is bumper deep, doesn't mean the backside of the radiator isn't getting a good coat of mud from the tires. I learned the hard way.:homer:

Was wanting to do this on my truck was curious the effects it would have on a diesel motor since i have not seen it done on one...another complication i was concerned with would be it being a crewcab would it put serious strain on the pump?

Hey look pictures finally :flipoff2:

this is a great idea. But is it worth doing on a street legal trail rig that only sees bumper deep mudwith 4" lift and 37's?


bumber deep mud on 37's is pretty thick mud. Definitely need some sort of radiator protection if your rig is not jacked 10' in the air and about to tip over when sitting.

Was wanting to do this on my truck was curious the effects it would have on a diesel motor since i have not seen it done on one...another complication i was concerned with would be it being a crewcab would it put serious strain on the pump?

I would get rid of the mechanical pump and run two electric pumps in line using all -16an lines. If you want to go on the cheap route you can use some cheap rubber hose and they have some 12v water pumps from Harbor Freight for about $30 a pop or so. Use one on each side(one going to the rad one going from the rad) perpendicular from each other and you can even put in a 3 position switch with a temp sensor so you can have it off, temp switch and on. Should hold you up just fine.

I would get rid of the mechanical pump and run two electric pumps in line using all -16an lines. If you want to go on the cheap route you can use some cheap rubber hose and they have some 12v water pumps from Harbor Freight for about $30 a pop or so. Use one on each side(one going to the rad one going from the rad) perpendicular from each other and you can even put in a 3 position switch with a temp sensor so you can have it off, temp switch and on. Should hold you up just fine.


there is no need for all of that. the stock pump will work just fine. my buddys truck has a 3" x 6" frame, filled with water. his stock pump moves it from the length of the truck and back without issue.

i used thin metal piping to run mine to the rear, with radiator hose where i needed a connection i could take apart. i welded up my own bends and connections everywhere else.

the biggest thing you need to do is have an air bleed at the high point at your motor.... other than that, it's pretty simple.

I see alot of people running exhaust tubing in the channel of the frame, and running regular radiator hoses to tie into the radiator and WP. I've also seen guys run the radiator in the front and run lines to one in the back also. I'd like to run mine in the rear, but im afraid it will get too hot in the cab. (K5 Blazer)

do you have to worry about rust forming on the inside of the pipe if your using metal for the runners to the rear? ive looked into other options but stainless is expensive and pvc is not great for cold weather so if yall have not had any trouble with it then i may give it a shot.

I ran rear mounted radiator on my last two rigs. I ran a large four core chevy radiator with dual electric fans. There is no need for auxiliary water pumps as the stocker will get the job done just fine. To combat rust I used galvanized fence pipe to run the water in. Some have used rubber hose all the way to the back but I like the fact that the water will lose heat on the way to the radiator and back when running metal pipe. You definitely must have an air bleed at the highest point of the motor. I used a petcock from a radiator to purge the air out. I also drill a small 1/8" hole in the t stat so when you fill up your system it will bleed all the air out instead of having to warm the motor up to finish filling. Also I've seen a lot of systems done wrong where they crossed the hoses and ran the return to the bottom and the suction to the top. Make sure the lower radiator hose goes to the bottom of the radiator and the top hose to the top.....and make sure you get lots of air flow across the radiator....properly designed systems will work with all the stock parts.

yeah, ive heard of people using concrete hose but it too is expensive. the galvanized direction seems to be the way to go for budget builders like me. do you still use a valve on the engine if the rad cap is the highest point in the system?

any pics of these set ups?

and what do you guys think about just running an extra water container in the back for extra water supply???? good or bad idea???

I wouldn't worry about rust. Antifreeze is pretty good at combating the formation of rust. Cast iron blocks don't seem to rust from the inside out.

In this truck you can see the galvanized exhaust pipe right above the frame in the front wheel well.
http://i3.photobucket.com/albums/y55/grandeyota/RIP2.jpg

I don't think you would need an extra tank. You already get the extra capacity from the length of tube. Between the inlet and return lines (2" IIRC) going from the bed to the engine bay, there was quite a bit more water needed to fill it. The stock water pump in the 304 (wagoneer frame/drivetrain) seemed to keep the water moving just fine.

Another guy I know works for a pool company and he gets the stainless hand rail tube from near the pool steps whenever they tear one down. If ya know a pool guy it might be a good cheap source. It already has nice bends too :flipoff2:

i have always used the pipes out of a toyota mr2 , they come with bleeds and all and are s/s , and pretty much every mr2 has them still in it

I did mine an interesting way, I run two aluminum radiators in the bed, I turned my electric water pump upside down so instead of going out bottom passenger side it goes up to the drivers side. Then I turned the neck on the intake around so both lines run right down the intake next to the valve covers and down the back of the motor and follow the bellhousing of the tranny and then go up into the bed. It worked really slick. I run a front and rear motor plate and I didn't want the pipe going under each plate below the frame, this way it all stays confined in the engine compartment. I'll try to get some pics this weekend to better explain how they look. I just used exhaust tubing and radiator hoses at the elbows.

any pics of these set ups?

and what do you guys think about just running an extra water container in the back for extra water supply???? good or bad idea???

You didn't click on the link in post number one, did you? I run an overflow container off the rad cap, much like the stock setup. Thats it. As has already been mentioned, you are already adding a shit ton of extra capacity simply due to the remote tubing.

At the race car shop they also have a waterneck that has a radiator cap on it....run a cap at the engine and one back at the radiator....buddy has one like that...I prefer the petcock valve on the waterneck. You can find the waternecks with the thermovacuum switch on them so the neck already has threads..

I used aluminized exhaust tubing, way cheaper than stainless and easy to get. It's been on the truck for 6 years with no problems.

when i started my build i did not plan on putting the rad in the bed but with now room up front i had to put in the bed. anyway i used corrugated stainless steal hose. Its like the kits you use to make your stuff all pretty but i found and industrial hose web sight and ordered 30 feet of it to give enough and i used stander rad hoses to connect at the corners. As a bleeder Chevy lumanas have two in there blocks. The have a small hole when you unscrew them to let air out, it worked better for me than the rad drain cock.

Skeeter

In my next version, I will use 1 3/4 aluminum tube, .090 wall. I got a bunch of it, cheap. The military used to use them for tent stakes on the GP Medium tents... and they have slip fit couplers, so i if i want to weld it, i have an inner liner at the weld... light, cheap, dissipates heat, and fits in my tubing bender for cool looking bends.

anyone actually have any pictures of how to mount the radiator in the rear of a wrangler?

heres what i got
THE PUP
Samurai rear mount ( hot as hell in the cab )
Hard to get good pictures its tiny back there :D
http://i294.photobucket.com/albums/mm112/TRAINHORN69/radiators004.jpg

http://i294.photobucket.com/albums/mm112/TRAINHORN69/radiators003.jpg

http://i294.photobucket.com/albums/mm112/TRAINHORN69/radiators002.jpg

http://i294.photobucket.com/albums/mm112/TRAINHORN69/radiators005.jpg

PIT BULL chevy s-10 bed

http://i294.photobucket.com/albums/mm112/TRAINHORN69/radiators007.jpg

http://i294.photobucket.com/albums/mm112/TRAINHORN69/radiators009.jpg

Train Horn, A couple of quick questions on the sami. How warm would you say it gets in there? about what temp(motor) does it run? is it a pain to fill the gas tank with the rad there, and how warm does the tank get and does it/did it cause fuel issues? a last one, are the fans set up as pushers or pullers? thanks.

Train Horn, A couple of quick questions on the sami. How warm would you say it gets in there? about what temp(motor) does it run? is it a pain to fill the gas tank with the rad there, and how warm does the tank get and does it/did it cause fuel issues? a last one, are the fans set up as pushers or pullers? thanks.

As soon as motor hit's 160 you start to feel it ,also living in florida its hot on top of that , also depending on how hard im running it can get really hot in there (210) but not so much that i can't take it , but have had others that i've let take it for a spin and cry about the heat :shaking:
filling the tank we stand on back bumper and funnel in that way , it's not to bad .
funny you mention fuel issues , my fuel pump has taking a shit , have been noticing lately its bogging down when you flip the switch and has just cut right off on me,i think its had it !!!!! So we are replacing it today .
as for fans being pushers or pullers i'm not sure, but i will find out .

My radiator had no choice but to be in the back , i run a 358 and there isnt room under that hood for a tooth pick ..........lol
If you ever need info let me know i'll do my best .

see above post for further info if you missed it

to answer the fan question

Pit bull truck has pull fan's
The pup has push fan's

:D

Thanks for the info. If you want even less room in there, stuff a bbc in it. one of the guys up here had one setup for drags and had a rad,water tank and pump on a cart to cool the motor for the same reson. The question about the gas tank was i thought it might get warm enough to cause fuel delivery issues, good to see that is not the case.

Mine is a BBC in a CJ and was hoping to see how others have placed/mounted the radiator successfully.

Here is my rear mounted radiator. Its all E-bay stuff (fan, radiator, pump). I used aluminized pipe down each side. Once I got the air out of it, it works awesome. The motor is bored .60 over, 13.5 to 1 pistons, and a stroker kit on racing gas and it stays around 155 driving around (drove it 3 miles back to the shop from a 4th of July display) and only got to about 190 doing a long freestyle.

http://farm3.static.flickr.com/2445/3570963810_c3808e233c.jpg

Good thread! Its nice to see some different ideas.

My setup in my cj5. I used 1.25 type L copper and brazed fittings for tubing.
No overheating since I made the shroud for the fan and put on the3 back as a puller.

http://i63.photobucket.com/albums/h154/jsjeep/shop011.jpg

http://i63.photobucket.com/albums/h154/jsjeep/jeepproject058.jpg

iniviate, does your friend use the whole frame as plumbing? I would think that would add a lot of water to the system, but would also add cooling ability due to the extra convection surfaces.

iniviate, does your friend use the whole frame as plumbing? I would think that would add a lot of water to the system, but would also add cooling ability due to the extra convection surfaces.

I've always thought that this would be pretty cool, cooling wise; but always gave me a little pucker corrosion wise. Theoretically, you shouldn't have any corrosion with the properties in the anti frieze, but we all know that doesn't always play out like it should.

I'm glad to see this thread is still prospering with more ideas and builds. When I first did my rear mount radiator nearly ten years ago most people had never seen anything like it and were totally confused. Today, its become far more common and there is a great deal more hands on experience and information.

Keep it up, folks :smokin:

With small volume/surface area frame, you could increase the ability to cool quite a bit. The only concern for me would be the temperature gradients in the frame may cause hotter parts to expand too much relative to cooler parts.

iniviate, does your friend use the whole frame as plumbing? I would think that would add a lot of water to the system, but would also add cooling ability due to the extra convection surfaces.

yes.... it took a lot of water.

the whole frame would be steaming when he came out of the mud. :laughing:

ttt lets keep this going

Gunna dig this one up from the grave yard. Anyone ever use 1" galvanized conduit? Just curious because I have a bunch of it laying in the back so if it is useable i'll def put it to use.

Edit: And I mean on the long stretch down the frame rail. I will use some flexible rad hose in the motor compartment and in the bed of the truck.

not 100% sure on this, but have been told that galvanized wreaks havoc with corrosion inside the engine when it's used as coolant lines. maybe google it if no one can confirm this.

hmmmm. Will have to look into this. I'll try google and i'm sure someone will chime in with their opinion or fact on the subject.

not 100% sure on this, but have been told that galvanized wreaks havoc with corrosion inside the engine when it's used as coolant lines. maybe google it if no one can confirm this.

I've heard the same thing, in that there can be some funky chemical interactions. Having never used the stuff myself, I can only repeat what I've heard (albeit from reputable sources). Personally, I'd rather stick with copper pipe, or rubber hose.

Does anybody have tried these: http://www.jamestowndistributors.com/1/1/286-zinc-anodes-pencil-zinc-anodes-brass-cap.html

Personally, I'd rather stick with copper pipe, or rubber hose.
copper for sure, but i don't think i'd run more than a foot and a half of rubber hose in one stretch unless it had one of those spring forms in it to keep it from squeezing itself closed.
Does anybody have tried these: http://www.jamestowndistributors.com/1/1/286-zinc-anodes-pencil-zinc-anodes-brass-cap.html
i don't know that this would do any good for this situation, but the theory sounds plausible in how it works. maybe i'll do a little search to see if i can find out exactly what type of reaction happens between anti-freeze/coolant and galvanized pipe.

i'm using galvanized conduit.... i'll report back if there is a problem.

Hmmm definately do that. You gunna have the motor torn apart anytime soon to where you can check it out? I'm gunna try and have this put together before summer hits.

Iniviate, what rad and fan setup r u running?

Hmmm definately do that. You gunna have the motor torn apart anytime soon to where you can check it out? I'm gunna try and have this put together before summer hits.

i'm thinking about building the engine this summer.... but it won't be apart in the next couple of weeks, if that's what you're asking.

Iniviate, what rad and fan setup r u running?

it's a nascar radiator and a taurus fan.


http://www.jaxracing.com/chris/rad2.jpg

http://www.jaxracing.com/chris/rad3.jpg

Thanks I just read it in ur build thread. That radiator is huge!

i'm thinking about building the engine this summer.... but it won't be apart in the next couple of weeks, if that's what you're asking.

Ahhh, that's cool. I'm gunna go ahead with the galvanized I have And if you do tear down and find any issues i'll just re-do mine with copper. You can be the test dummy. :grinpimp:

Ahhh, that's cool. I'm gunna go ahead with the galvanized I have And if you do tear down and find any issues i'll just re-do mine with copper. You can be the test dummy. :grinpimp:

a bunch of mud trucks before me have done it.... i think it'll be fine. we'll see i guess.

a bunch of mud trucks before me have done it.... i think it'll be fine. we'll see i guess.

You think 1" will be fine? Me n my buddy were talking about it and idk if that is big enough...

Your thoughts?

i used 1 1/2" .... it's basically the same size as all my radiator hoses, which made things easy.

i used 1 1/2" .... it's basically the same size as all my radiator hoses, which made things easy.

Yea, that's another thing I was thinking about. I would have to get all kinds of adapters and b.s.

I'm gunna talk to my pops tomorrow and see if he can grab me some scrap 1 1/2 from work just so I can be safe. All my hoses are 1.5" also.

I run 1.5" EMT (galvanized) in my toyota for about a year now with no ill effects. I havent torn down the motor (probably never will), but it still runs the exact same way it did when I moved the radiator to the bed. I used 1.5" agricultural sprayer hose and 1.5" flexible radiator hose for all of the solf connections. No leaks as of yet using double worm-gear hose clamps from Lowes.

Stock GM 4.3L radiator w/ ford taurus fan, keeps it cool all day long. Almost too cool.
http://i818.photobucket.com/albums/zz104/aletz12485/radiatorhoseroating009.jpg
http://i818.photobucket.com/albums/zz104/aletz12485/forsale005-1.jpg
http://i818.photobucket.com/albums/zz104/aletz12485/radiatorinbed001.jpg
http://i818.photobucket.com/albums/zz104/aletz12485/IMG_2806.jpg

Well unfortunately I won't be joining the galvanized guys. lol
I called the ol man today and he hooked me up with 2 sticks of 1.5" aluminum conduit.
I'll post detailed pics once we're done.

But I got a question, all these guys are running petcocks on there thermostat housing, so could just drill a hole in my lower intake and tap it for a petcock? Right at the thermostat housing?

I was wondering what aluminum tube I could use to run from the front to the back that I can bend, the local supplier said his usual is aircraft grade and will crack instead of bend.

When I had my truck I cut up a trampoline frame and used that for the piping. It worked great.

I was wondering what aluminum tube I could use to run from the front to the back that I can bend, the local supplier said his usual is aircraft grade and will crack instead of bend.

I'm using aluminum conduit. That can be bent. I'm not sure of any other terms for it, I just know it as conduit. It's industrial grade aluminum pipe that electricians run wire through. Maybe check an industrial supply store?? Or electrical supply store.

Alright, back to the top. We have built the fugly bracket that will hold the radiator. (I hate it, the radiator will eventually be mounted on rear roll bars, but for now this will have to suffice.) Have the pipe ran down the frame rails also, now I am just looking at my options to get the coolant from the motor/radiator to the pipe. I am thinking about going to the junkyard and cutting a bunch of elbows off of radiator hoses and running a neat and clean system down there. But I would like to see where you guys are getting the nice looking clear braided hose that I have seen before.(I think it is for pool pumps??? Not sure...) If that isnt too pricey I may go that route. Or if anyone has any other alternatives that are decent prices let me know what it is and where the hell to get it at. Thanks fella's.

Some one here said they used 1.5" piping with rubber elbows but I cant find it now...

Where did you or would you get rubber elbows?

I'm running through the frame on mine. The thing I am worried about is I'm going to go into the frame at the mid point. I'm wondering what the water on the other side is going to do.
http://i165.photobucket.com/albums/u44/nnelgrepooc/b6e3edd7.jpg

That was why I shied away from doing my frame as the coolant lines, what about a rubber hose in the frame rail? I might change mine up like that.

To add to the thread. I have a 3.8 v6 in a samurai. Rear radiator. 1 3/8 rubber hose, gutted thermostat and a Taurus fan. The radiator is a stock mustang radiator. It runs 150-160*

Well Andy it would take a 1lb out of your 5lb bag lol. I was impressed by how well GZ did. looks like you had fun.