Wildcat Forum banner

1 - 20 of 22 Posts

·
Premium Member
Joined
·
1,746 Posts
Discussion Starter #1 (Edited)
I thought this was worth a separate thread from my turbo build, which is the root cause for my wanting additional cooling capability. Sand-n-Sea has shown us how to do it right (https://www.wildcatforums.net/forum/projects-how/91711-dual-core-dual-pass-radiator-project-hot-cats.html) if you have good tig welding skills and equipment. I have neither, but his dual core / dual pass creation piqued my curiosity and I had noticed that the mounting flanges at the front and rear of the radiator are completely symmetrical top to bottom and left to right. I could see that it would be possible to mount two radiators back to back, so I picked up a second radiator.

It turns out that the drain plugs are just a bit too tall, but this was easily addressed by grinding off the raised hex. With that done, the tank flanges control how close you can mount the radiators. The resulting gap between the mounting flanges at the front and rear of the radiators is just over 1". For now, I've simply strapped them together with safety wire.
IMG_1122.JPG

I have 1x1x1 aluminum channel coming from Online Metals to bridge the gap. The nut-serts on the radiator flanges are 1/4x20, so I'll be making a trip to Ace Hardware to buy a dozen screws to hold everything together.

Those with sharp eyes and good observation skills will notice that the bottom flange and the mounting ears on the bottom radiator have been removed. I needed additional clearance between the front of the lower radiator and the plastic radiator cowling. Somewhat surprisingly, the drain plugs, mounting ears, flange and the stock mounting tabs are the only modifications needed to make the radiators fit inside the cowling.

That was great, but radiators need fans, and there was not enough room for the stock shroud and fans. The fans sit on top of the shroud with four screws holding them in place. The threaded inserts in the shroud are also exposed on the back side of the shroud, so I ground down all of the un-used mounting tabs around the perimeter of the fans and enlarged the hole in the shroud so that the fans could be mounted to the back of the shroud. I did all of the work with an angle grinder. Notice that I had to put a bevel on the mounting posts to accommodate the shape of the mounting ears on the fans.
IMG_1113.JPG IMG_1112.JPG

Changing the way the fans are mounted resulted in a much shorter package. The fan in the foreground is mounted in the normal arrangement, while the fan toward the rear was mounted to the backside of the shroud:
IMG_1114.JPG
 

·
Premium Member
Joined
·
1,746 Posts
Discussion Starter #2 (Edited)
In addition to the changes I described above, the front radiator mounting points have to change. I had already removed them when I built my hidden harness bar, but I had to cut them down further to make room for the double stack. All I left was the mounting pad for the cowling:
View attachment 243737

I mounted the radiator stack to the rear mounts using the lower radiator mounting ears. At the front, the radiators are resting on the cut-down brackets. The double radiators fit pretty nicely!
View attachment 243739 View attachment 243741

There is no room for the overflow bottle in it's normal position, where it also restricts air flow through the radiator core(s). It "might" be possible to shoehorn it into the opening at the top of the cowling, but for sure there is room to install it between the radiator tanks and the cowling on the passenger side.

My next decision will be how to plumb the two radiators. My fallback solution is to make a pair of thermostat housings and give each cylinder it's own radiator. I would use the OEM thermostat housing (without a t-stat) to combine the two circuits and feed the water pump. One or more of the UTV cab heater companies make such thermostats, but it would add a fair amount of cost.

I am hoping that I can run the two radiators in series, plumbing the outlet from the lower radiator to the inlet on the upper radiator on the passenger side. I'm wary of how much the second radiator might restrict flow, probably because I very nearly ruined an expensive pro-built cylinder head on my race car when I tried to use a radiator that had been sitting on the shelf for several years. It was so corroded that the pump couldn't move enough coolant. I don't want to repeat that! My next step will be to see how long X amount of water takes to flow through one radiator, then add the second and see how much longer it takes. If there is a big difference, I'll go with the dual thermostat setup.

The one thing that I am certain of, is that this setup will be a PITA to burp. I've been wondering if I could install a bleeder into the plastic tanks, a lot like how a metal tire stem is installed in a wheel. Maybe I'll see just how hard it is to burp before I take that step.
 

·
Premium Member
Joined
·
1,746 Posts
Discussion Starter #3
My primary goal was to have enough cooling capacity to be able to run the turbo kitty hard without any overheating, but I also wanted to see if it could be done without any special skills or tools. That was pretty much predicated on running the radiators in series, but I've decided to run them in parallel, with each cylinder having it's own radiator. That means a pair of custom thermostat housings will be required.

I'm making the first housing on my lathe, but the thermostats that I'm using (Gates 34037S, 192 degrees) should work clamped inside a 1.5" radiator hose. The dimensions on a copper 1 1/4" by 3/4" solder-joint coupler look like they could be used to get from 7/8" heater hose (the size of the nipples on the radiator) into 1 1/2" hose for the thermostat and then back down to 7/8" hose. Those are not common couplers, but the Ace Hardware website shows that they can be ordered for pickup in just a few days. I may order a couple - making the housings on my lathe is time consuming.
 

·
Registered
Joined
·
41 Posts
Interesting! this is the sledding world but guys seem to of been using the Skii doo XM thermostat housings for some mods I've seen, I can't remember what their temperature rating was but good flow and cheap to get.
 

·
Premium Member
Joined
·
1,746 Posts
Discussion Starter #5
Octane, I wish you had posted that a few days ago, but of course I hadn't shared my latest plans. Oh well...

Some of the ones pictured currently on ebay look like they would have worked. Maybe someone will follow in my footsteps and benefit from that great piece of intel.
 

·
Registered
Joined
·
41 Posts
haha it happens but exactly... now you know! and or everybody else if they ever stumble upon this thread.
 

·
Premium Member
Joined
·
1,746 Posts
Discussion Starter #7
Everything fits under the stock plastic, but just barely. I'll post pics later to show how I made some of the adapters and how I used most of the stock hoses. I also have a trick to share about purging air from the high point in the radiators.
 

·
Premium Member
Joined
·
1,746 Posts
Discussion Starter #8 (Edited)
The ID of the radiator hoses varies from ~ 3/4" to 7/8" at the radiator inlets and outlets. 3/4" copper pipe and couplers are pretty much ideal for joining the various pieces of stock hose and the 7/8" hose that I added. The only thing missing are the raised rings for hose retention, but a propane torch, some bell wire and a bit of solder fixes that:
IMG_1127.JPG
This is a coupler, which is ideal for joining 7/8" hose. I made other fittings from 3/4" copper pipe (tubing) and another using the coupler at one end and 3/4" pipe at the other. I took the pic before I smoothed the solder rings with a file and some sandpaper.

There was plenty of room at the rear cylinder for a custom thermostat housing that replaces the 90 degree water outlet on the cylinder head:
IMG_1126.JPG

The exhaust primary is a bit too close for something like that on the front cylinder. The thermostats that I chose have a rolled flange around the circumference. The flange is 1.5" in diameter and fits perfectly inside a piece of 1.5" hose:
IMG_1128.JPG IMG_1131.JPG
As I mentioned previously, a 3/4 to 1 1/4" copper pipe reducer/coupler is perfectly sized to go from 7/8" hose to 1 1/2" hose. I ordered a bag of five via Amazon, but when they arrived the big end was the same size as 1 1/4" pipe instead of sized to accept the pipe. I had to add a coupler (actually half of a coupler), and then do the bell wire trick:
IMG_1134.JPG
Two of these and a short length of 1 1/2" hose quickly makes a nice, cheap thermostat housing.

Since the front cylinder thermostat was going to be about a foot away from the cylinder head, I was concerned that the thermostat would take too long to open. I drilled several small (1/16"~) holes around the perimeter of the t-stat so that there would always be some coolant flow. This turned out to be a mistake - the front cylinder takes much, much longer to come up to temp compared to the rear cylinder. The sensors are in the same position (part of the new coolant outlet), and I had verified their readings against each other, so it would seem obvious that my bypass holes were a bad idea.
 

·
Registered
Joined
·
2,406 Posts
Your project is over the top sir. But once its all done you will have a nice ride for sure. Only real place you will be pushing it will be in Glamis or wide open desert and even then your not really WOT.
 

·
Premium Member
Joined
·
1,746 Posts
Discussion Starter #10 (Edited)
Now for the plumbing. The stock hoses were surprisingly adaptable.

For the rear cylinder, I installed the custom t-stat housing, a length of very flexible 7/8" heater hose and the U shaped hose that formerly connected the front cylinder outlet to the OEM t-stat housing:
IMG_1145.JPG
The storage tray butts up fairly tight to the radiator. It might be possible to trim the radiator flange and mounting ear so that the U hose curves left instead of right, but I didn't want to make any changes that would prevent the radiator from being mounted and used in the normal manner.

I don't have clear pictures of the routing for the front cylinder to radiator layout. The hose runs straight out for about 10", then turns toward the back of the car and connects to the radiator. I had a molded 90 degree 1 1/2" hose left over from a different project that I used as a t-stat housing (the pic will be much easier to understand if you click on it, which will rotate it to portrait mode):
IMG_1149.JPG
I'm sure this particular connection could be solved any number of ways.

The OEM radiator outlet hose connects to the lower radiator outlet (outlet points down) and another OEM hose piece connects to the top radiator outlet (outlet points up). I wanted to connect the two circuits across the top of the radiator so that air could easily get to the filler neck. I used two copper Tees and stubs. I don't expect to ever need to dis-assemble that hose and fitting assembly, so I used Oetiker clamps for the hose connections:
IMG_1148.JPG
The two blue hoses run down to the OEM t-stat housing which merges the two coolant flows. I spliced another piece of OEM hose that had a bit of a wiggle in it to the normal t-stat hose. That got the lower end of the hose a little further away from the exhaust primary. My harness bar / radiator mount would have pushed the blue hoses too close to the cockpit plastic if I had gone over the front of the harness bar. Instead, I removed most of the radiator flanges and the 1" aluminum channel spacer.

That completes the routing of the hoses, but I had been worried about burping the lower radiator. The radiators are laid over at a flatter angle than stock, which enlarges the air pocket at the top (remember, the outlet points down in the lower radiator). I fished a piece of copper tube through the passenger side radiator outlet hose, with the tube sticking up into the top corner of the radiator tank. I bent the other end so that it finishes just below the radiator cap:
IMG_1146.JPG IMG_1147.JPG
The tiny copper tube gives the air otherwise trapped in the upper part of the lower radiator a way to escape. Any tubing that will retain it's shape at radiator temps would work. I would have used aluminum if it was available locally, if only to completely remove any chance of galvanic corrosion. I *think* the two metals have to be touching to corrode, but my confidence in that is only about 60%. I have to say that it was extremely gratifying to watch the air bubbles trickle out of the little copper tube as I filled the radiators.

Relocating the OEM temp sender was a little tricky. It uses straight threads and an o-ring to seal. I was able to machine the mounting boss into the front cylinder outlet, but I suspect there may be adapter fittings available, or it might be possible to find an NPT sender with the same resistance pattern. I used a bolt left over from a Mazda Miata project to plug the original location. The Japanese auto companies love to use bolts with an integral flange instead of a bolt and washer, and it worked perfectly for this.
 
  • Like
Reactions: izom

·
Premium Member
Joined
·
1,746 Posts
Discussion Starter #11 (Edited)
I suspect anyone that might attempt this project has a turbo or supercharger. The charge air piping for your system could make this easier or more difficult. MCX routes the charge air around the lower corners of the radiator, up through the radiator grills to the intercooler. I had to add a hose with a 45 degree angle on the driver's side to get everything to line up. The passenger side was even trickier, with the charge pipe, radiator hose and the gas tank filler hose, but it all worked out without any modifications.

The attachment points for the heat shield and the rear cylinder ignition coil bracket have to change a bit, but these are minor problems that probably don't need discussing.

In the pics in the previous post you can see how I squeezed the overflow/coolant recovery tank into the gap on the passenger side. The added volume of the second radiator also adds to the volume of coolant that is pushed out as everything heats up and is then pulled back in as it cools. The stock recovery tank will fill to overflowing and then be completely emptied, so I'm working on a plan to add some capacity.
 
  • Like
Reactions: mtgott and izom

·
Premium Member
Joined
·
1,746 Posts
Discussion Starter #14
I just spent 2 and a half days chasing Sand-n-Sea around Ocotillo Wells. We rode fast, but not flat-out fast (keep in mind we both have turbos, so we probably rode harder than a stock X could manage flat-out). The highest temp I saw was 197f, and I checked it frequently. I'm very pleased.
 

·
Registered
Joined
·
997 Posts
Fun times! Mark's version on the double radiator is easier and well thought out. Excellent job!
 
  • Like
Reactions: izom

·
Registered
Joined
·
1,233 Posts
...cmon guys wheres the pics or vids from you 2 ridin !? ;- ()
 

·
Registered
Joined
·
41 Posts
Awesome to see guys doing all this custom stuff, I'd love to have a turbo on my ol wildcat BUT as it's stock I worry about blowing belts and let alone the rear diff anyways lol..... maybe down the road on another chassis ;)
 

·
Administrator
Joined
·
27,615 Posts
Awesome to see guys doing all this custom stuff, I'd love to have a turbo on my ol wildcat BUT as it's stock I worry about blowing belts and let alone the rear diff anyways lol..... maybe down the road on another chassis ;)
Edited your post. You can't promote sites like you did in this video. It's against forum rules. Only Supporting Vendors can promote their sites.
 

·
Premium Member
Joined
·
1,746 Posts
Discussion Starter #19
...cmon guys wheres the pics or vids from you 2 ridin !? ;- ()
turbos at Ocotillo.jpg

My wife took lots of pictures of the area, but hardly any of the Wildcats. Sand-n-Sea's daughter snapped this pic.
 
  • Like
Reactions: izom and DeanTeck

·
Registered
Joined
·
41 Posts
Awesome to see guys doing all this custom stuff, I'd love to have a turbo on my ol wildcat BUT as it's stock I worry about blowing belts and let alone the rear diff anyways lol..... maybe down the road on another chassis <img src="http://www.wildcatforums.net/forum/images/smilies/wink.png" border="0" alt="" title="Wink" class="inlineimg" />
Edited your post. You can't promote sites like you did in this video. It's against forum rules. Only Supporting Vendors can promote their sites.

Sorry did not use it to promote but just sharing a YouTube video.
 
1 - 20 of 22 Posts
Top