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I remember your post, and I think I will probably end up doing the same thing soon. Thanks.
Manufactured heat exchanger kit (Full radiator delete) for sale
- Thread starter XRTEngineered
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I remember your post, and I think I will probably end up doing the same thing soon. Thanks.
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Yes it certainly is acting as a radiator. My heated bars are also on that circuit and acting as a radiator as well.
It was a very cold day with unusually fluffy and deep snow. We ride a lot of powder, but not always that deep. So I want to try this setup in a variety of conditions before I make any big changes.
I suspect I will end up insulating that bottle in some way so it doesn't create ice, and seal the motor off better with a bib (as described by Chadx).
Regarding the XRT coolant bottle and radiator guards acting as a bit of a heat exchanger, that is an intended (though rare) use case for my setup. Though not nearly as efficient as a real radiator without fins and much reduced surface area than a radiator, there are situations where heat exchange will be a benefit. As mentioned, to make my particular plumbing easier, I have my tunnel cooler return line going to the XRT coolant bottle. I intentionally bolted the bottle tight up against my raw aluminum Unabiker radiator guard to facilitate heat exchange when/I want it. Running my bib, when I still had radiators, proved to work well and greatly limit heat exchange (my powder-riding engine temps stayed nice and warm). And, with this setup, if I encounter a trail where keeping temps down is challenging with the tunnel cooler only, I can remove the bib and let air hit the coolant bottle/radiator guard and allow cool air to push back through the engine bay. It won't be near the heat exchange of radiators, but I don't want that and it will rarely be needed; just an easy to implement backup plan that will give slightly more cooling than when I'm all bibbed-up and relying only on the tunnel cooler.
My goal for adding tunnel cooler and deleting radiators is to avoid putting the bib off and on each when I transition from trail, to deep powder, and back to trail. The other condition I was solving for were long,, high-throttle pulls up steeps. That was a situation where my temps could get high enough that I'd have to turn out to let the temps come down because the bike wasn't getting enough powder/cooling.
If the only time the bib comes off is a few times per season for exceptionally boiler-plate trails, I'll consider the tunnel cooler install/rad delete worth the time and expense and call it a success. Much better than uncovering and covering the radiators 4 or 5 times per ride (trail to powder transitions) and turning out of long pulls (due to high temps) a couple times per ride.
My goal for adding tunnel cooler and deleting radiators is to avoid putting the bib off and on each when I transition from trail, to deep powder, and back to trail. The other condition I was solving for were long,, high-throttle pulls up steeps. That was a situation where my temps could get high enough that I'd have to turn out to let the temps come down because the bike wasn't getting enough powder/cooling.
If the only time the bib comes off is a few times per season for exceptionally boiler-plate trails, I'll consider the tunnel cooler install/rad delete worth the time and expense and call it a success. Much better than uncovering and covering the radiators 4 or 5 times per ride (trail to powder transitions) and turning out of long pulls (due to high temps) a couple times per ride.
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What skid year / model / size are you running? As I have gotten feedback from some customers, Theres an issue to address on some 2022+ skids.
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I have a 2023 Aro S Pro 129 3"
After running a heat exhanger since my 2014 build on a KTM 500 I found that:
1. any exposed aluminum to snow is a killer for good 190 running temps, I ditched my aluminum filler set up for a plastic arctic cat filler neck and , less heat loss in the powder, no annoying ice build up, no radiators.
2. after building several engine covers and finally getting the engine thoroughly covered 184 degree temps in all snow conditions...........EXCEPT when heading down hill packed trail to truck, I tend to click it into 6the gear and loaf along at low rpm pretty fast clip..........220 degrees quickly because with no engine rpm the coolant isn't circulating fast enough, soon as I drop back to 5th gear same ground speed more engine rpm, temps go right back to 184. Going up that same road in the morning working the engine with rpm, never an issue.
3.One of our riding group, KTM sno bike with high volume after market water pump kit, had to go back to stock to get temps up more consistently, just wanted to run too cold in many conditions...............no radiators and heat exchanger.
4.I have welded up several sets of heat exhangers for sno bikes out of the Wahl bros aluminum stock, and as I have posted before hand, only takes a dinky heat exhanger to cool a 60hp four stroke. . I made two heat exhangers to fit inside the frame work on the older TS tube type sub frame, about 4" by 8" each and valves to run one or both, spent most of the year running one 4" x 8" aluminum exhanger, was actully better the first 2/3 of the year out in the powder.
5. And with heat exchnger and a totally covered motor, 180-190 temps, a KTM is a more powerful happier engine.
1. any exposed aluminum to snow is a killer for good 190 running temps, I ditched my aluminum filler set up for a plastic arctic cat filler neck and , less heat loss in the powder, no annoying ice build up, no radiators.
2. after building several engine covers and finally getting the engine thoroughly covered 184 degree temps in all snow conditions...........EXCEPT when heading down hill packed trail to truck, I tend to click it into 6the gear and loaf along at low rpm pretty fast clip..........220 degrees quickly because with no engine rpm the coolant isn't circulating fast enough, soon as I drop back to 5th gear same ground speed more engine rpm, temps go right back to 184. Going up that same road in the morning working the engine with rpm, never an issue.
3.One of our riding group, KTM sno bike with high volume after market water pump kit, had to go back to stock to get temps up more consistently, just wanted to run too cold in many conditions...............no radiators and heat exchanger.
4.I have welded up several sets of heat exhangers for sno bikes out of the Wahl bros aluminum stock, and as I have posted before hand, only takes a dinky heat exhanger to cool a 60hp four stroke. . I made two heat exhangers to fit inside the frame work on the older TS tube type sub frame, about 4" by 8" each and valves to run one or both, spent most of the year running one 4" x 8" aluminum exhanger, was actully better the first 2/3 of the year out in the powder.
5. And with heat exchnger and a totally covered motor, 180-190 temps, a KTM is a more powerful happier engine.
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So what is the issue?
My install is complete. Now to test it out....
@AllHatNoCattle In your image above, you used spiral hose protector on your coolant hoses. I have some of that inbound for another project and I also plan to use it on my snowbike build, but I just noticed that the temp range, of the particular brand that I ordered, is listed at "-60F to +175 Degrees F". Do you know the temp range of the hose protector you used? Any signs of degradation? Perhaps since that particular section of yours is back away from the engine and part of it in open air, even if your is rated like mine, it won't be any issue. On my YZ450F, a big section that I plan to spiral are inside my Selkirk surround, so won't get much air flow, and also only a few inches above my exhaust. I might be in for a mess. Ha.
I'll have to give it a good 200 degree engine/coolant temp heat cycle in the shop with no air flow to determine if the melt characteristics of my particular spiral hose protector are "it got a little soft" or if it goes straight to "melted drip-mode". Ha.
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Hi Chadx,
I actually just got that from the hose supply shop I bought the blue hose from. I never asked about heat ratings, and where I have it placed I cant see it getting very hot. I couldn't say how much heat it can handle. You could be in for a mess if you get too close to the exhaust.
Did you see the heat shield stuff I used in other parts of the hose? That was header wrap I got from an auto parts store here. I had to cut it down and then sew the cut ends to avoid fraying, but I think it would do a good job at deflecting heat. I originally had it on the hose sections close to my pipe, but then realized I had enough clearance with just the hose to be ok without it.
C
Got my HX up and running, did great on the first ride of the year.
I kept the right side radiator and restricted the flow through it a little.
The left side keeps the C3 heated bars fitting and ties into the HX.
Not as light as I could get, but it was simple with the fittings i could get.
Used a 1" to 3/4" PEX reducer out of the Tee in the frame.
A few more 90s and lots of hose clamps.
I kept the right side radiator and restricted the flow through it a little.
The left side keeps the C3 heated bars fitting and ties into the HX.
Not as light as I could get, but it was simple with the fittings i could get.
Used a 1" to 3/4" PEX reducer out of the Tee in the frame.
A few more 90s and lots of hose clamps.
C
Second ride in with the HX.
It was about 10 f most of the day.
Temps were pretty much between 170 and 190 all day.
Id say it is doing exactly what its supposed to do, and the thermostat does as well.
The only shortcoming ive noticed is the extra ice build up out back.
Got pretty thick on the structural supports to the ARO 3 assembly.
It was about 10 f most of the day.
Temps were pretty much between 170 and 190 all day.
Id say it is doing exactly what its supposed to do, and the thermostat does as well.
The only shortcoming ive noticed is the extra ice build up out back.
Got pretty thick on the structural supports to the ARO 3 assembly.
@mumur I just buttoned up everything last weekend after a yard test and final coolant drain/fill. I sat and idled until bike was over 190F (my thermostat) and then rode ahead 50 feet and it cooled right down. Did that 4 or 5 times. Mainly just to leak test (which I did with Evans Waterless prep solution as to not waste the Waterless itself). Even though it was a leak test, it was nice to see temp drop down like that. I then drained and refilled with Evans waterless and heat cycled it to get the air out. Just have to install one piece of protective rubber sheet around my hoses and secure to frame and will do a shakeout ride.
For shakeout, I'll put on about 10 miles but never go more than 1/2 mile or so from the truck and stay on the trail. And will stop often and just check everything over like coolant level, all hoses/connectors, chain tension, belt tension, track tension and all fasteners I had off which was a lot. I had the entire kit off the bike, entire skid out and apart to lube everything, pulled belt and pulleys off to replace cracked belt surround, new chain, radiator delete, tunnel cooler install, new temp gauge sensor, etc. so lots to keep an eye on. A shakeout ride, like I do it, is boring but makes for an easy recovery in case I messed anything up horribly. Ha. Then I'll go home and go through everything thoroughly in the shop. Then I'm ready for a real ride.
As a reminder, the only XRT part I used is the coolant bottle. I used C3 tunnel cooler since I have a Yeti. So that is why I'll start a different thread for my project rather than detail it here. But, I did leave images in this thread for my XRT coolant bottle install and I'll will post any opinions on that as the season progresses. So far, it was the ideal solution for a radiator delete and happy with it.
I see The Newph also did an install video for his XRT tunnel cooler and coolant bottle.
For shakeout, I'll put on about 10 miles but never go more than 1/2 mile or so from the truck and stay on the trail. And will stop often and just check everything over like coolant level, all hoses/connectors, chain tension, belt tension, track tension and all fasteners I had off which was a lot. I had the entire kit off the bike, entire skid out and apart to lube everything, pulled belt and pulleys off to replace cracked belt surround, new chain, radiator delete, tunnel cooler install, new temp gauge sensor, etc. so lots to keep an eye on. A shakeout ride, like I do it, is boring but makes for an easy recovery in case I messed anything up horribly. Ha. Then I'll go home and go through everything thoroughly in the shop. Then I'm ready for a real ride.
As a reminder, the only XRT part I used is the coolant bottle. I used C3 tunnel cooler since I have a Yeti. So that is why I'll start a different thread for my project rather than detail it here. But, I did leave images in this thread for my XRT coolant bottle install and I'll will post any opinions on that as the season progresses. So far, it was the ideal solution for a radiator delete and happy with it.
I see The Newph also did an install video for his XRT tunnel cooler and coolant bottle.
My 2020 gets that much ice build up as is it seems. Very interested in how this performs.
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To everyone waiting for my response on this thread- I deeply apologize for my absence and lack of a response.
I initially was waiting a few more days to get feedback and do more testing before I make a statement, and then I got busy and forgot.
I will keep tabs on this thread going forward, and answer all questions and concerns.
Also, for anyone that had purchased one and is not getting the cooling they wanted, contact me through email I will get it right for you!
@AllHatNoCattle - the culprit is within the track and skid design itself.
Little bit of background: When I started this project, all we had for testing was the first gen ARO and RIOT kits. On some of the setups we did, the small size heat exchanger was more than big enough for even icy trails. It just never overheated. As @CATSLEDMAN1 stated earlier: "only takes a dinky heat exchanger to cool a 60hp four stroke" which he has had success with on multiple setups.
And as evident by some other users giving their feedback here- works great! No overheating.
Who is having overheating issues on hard packed trails: those running a Gen2 ARO 3" skid.
From all the testing I could gather along with the help of several other guys, the conclusion we have come to is the skid design (more so the track) is made to perform on the snow and was not built to throw snow up at the heat exchanger. The 3" paddles do a good job to fling off all the snow when going around the rear idler wheel in a nice big roost and it doesnt make it to the heat exchanger. It appears the paddles are made from a softer composite and that plays a part in it.
To give more floatation the new tracks did away with windows down the middle, and snow cannot "exit" from the track as it spins around which would otherwise provide excellent cooling on the hard packed trails.
The solution for riding hard packed trails and not overheating on these specific skids is ice scratchers and /or a snowflap. Without them even snowmobiles overheat pretty quick.
Alternatively, you can run 1 radiator in line with the heat exchanger to give cooling on the trails, and heat exchanger for cooling on the playgrounds. But be aware of your hyfax still needing lubrication! Its very easy to burn up your hyfax with such a setup.
Nonetheless- riding on the mountain through trees or any hill climb it will never overheat which is what really matters. The trail is just for getting there...
Another change on the new skids is the position of the rear upper idler pulley changes the direction and ability for the track to throw snow at the heat exchanger when it is mounted in the forwardmost position.
To overcome this on the Gen 2 ARO skids and help with cooling on the hard packed and icy trails, we have a couple solutions.
- Larger heat exchangers: We now offer 3 sizes.
- Standoff spacers. Allows for more airflow between tunnel panel and heat exchanger. Also allows you to keep your gas can and toolbox mounted on the tunnel panel and no interference with mounting the heat exchanger.
- Hose fitting extension runners to position the heat exchanger in the most optimal location above the rear upper idler wheel.
More info on all of this on my website, take a look I've added alot on there: https://xrtengineered.com/shop/timbersled-aro-heat-exchanger
I initially was waiting a few more days to get feedback and do more testing before I make a statement, and then I got busy and forgot.
I will keep tabs on this thread going forward, and answer all questions and concerns.
Also, for anyone that had purchased one and is not getting the cooling they wanted, contact me through email I will get it right for you!
@AllHatNoCattle - the culprit is within the track and skid design itself.
Little bit of background: When I started this project, all we had for testing was the first gen ARO and RIOT kits. On some of the setups we did, the small size heat exchanger was more than big enough for even icy trails. It just never overheated. As @CATSLEDMAN1 stated earlier: "only takes a dinky heat exchanger to cool a 60hp four stroke" which he has had success with on multiple setups.
And as evident by some other users giving their feedback here- works great! No overheating.
Who is having overheating issues on hard packed trails: those running a Gen2 ARO 3" skid.
From all the testing I could gather along with the help of several other guys, the conclusion we have come to is the skid design (more so the track) is made to perform on the snow and was not built to throw snow up at the heat exchanger. The 3" paddles do a good job to fling off all the snow when going around the rear idler wheel in a nice big roost and it doesnt make it to the heat exchanger. It appears the paddles are made from a softer composite and that plays a part in it.
To give more floatation the new tracks did away with windows down the middle, and snow cannot "exit" from the track as it spins around which would otherwise provide excellent cooling on the hard packed trails.
The solution for riding hard packed trails and not overheating on these specific skids is ice scratchers and /or a snowflap. Without them even snowmobiles overheat pretty quick.
Alternatively, you can run 1 radiator in line with the heat exchanger to give cooling on the trails, and heat exchanger for cooling on the playgrounds. But be aware of your hyfax still needing lubrication! Its very easy to burn up your hyfax with such a setup.
Nonetheless- riding on the mountain through trees or any hill climb it will never overheat which is what really matters. The trail is just for getting there...
Another change on the new skids is the position of the rear upper idler pulley changes the direction and ability for the track to throw snow at the heat exchanger when it is mounted in the forwardmost position.
To overcome this on the Gen 2 ARO skids and help with cooling on the hard packed and icy trails, we have a couple solutions.
- Larger heat exchangers: We now offer 3 sizes.
- Standoff spacers. Allows for more airflow between tunnel panel and heat exchanger. Also allows you to keep your gas can and toolbox mounted on the tunnel panel and no interference with mounting the heat exchanger.
- Hose fitting extension runners to position the heat exchanger in the most optimal location above the rear upper idler wheel.
More info on all of this on my website, take a look I've added alot on there: https://xrtengineered.com/shop/timbersled-aro-heat-exchanger
C
I'm 15 rides into the season and no complaints about the tunnel cooler.
I kept the right side radiator because I was having trouble sourcing parts and pieces to plumb in the xrt coolant bottle.
I choked down the flow through the radiator to about a quarter inch hole.
Have not ridden on hard pack yet, actually have not rode in any condition that would challenge the cooling system.
Most of my rides it seems like heated bars are enough to keep everything cool,
Sometimes I have to turn them off too.
The system holds about 2 l of coolant now, and I'm sure with keeping one radiator my system is not in any lighter.
A coolant bottle that mimicked a radiator would make for easier plumbing, a 1-in fitting at the top left and 3/4 inch at the bottom.
All in all it has made for easy temperature management
Keep the engine blanket tight and if anything just turn off the bars if it's still too cool.
I kept the right side radiator because I was having trouble sourcing parts and pieces to plumb in the xrt coolant bottle.
I choked down the flow through the radiator to about a quarter inch hole.
Have not ridden on hard pack yet, actually have not rode in any condition that would challenge the cooling system.
Most of my rides it seems like heated bars are enough to keep everything cool,
Sometimes I have to turn them off too.
The system holds about 2 l of coolant now, and I'm sure with keeping one radiator my system is not in any lighter.
A coolant bottle that mimicked a radiator would make for easier plumbing, a 1-in fitting at the top left and 3/4 inch at the bottom.
All in all it has made for easy temperature management
Keep the engine blanket tight and if anything just turn off the bars if it's still too cool.
I've had my C3 tunnel cooler (on Yeti kit), radiator delete and XRT coolant bottle out about 5 times now. Of those 5 times, 4 I ran hot on the trails (Last time was right after snowstorm so plenty of snow-dust on trail to keep tunnel cooler doing it's thing). My advice is keep one radiator just to leave yourself with a good air-cooled option. I might put one of mine back in rather than the coolant bottle. I've experienced several times where temps climbed higher than I would have liked in sections where I could not duck off and catch any snow. A ski scratcher may also resolve, but unfortunately, the ski cable scratcher I ordered doesn't see like it will work on the back of my CMX ski because the back of that ski kicks up. I need to figure out if I can rig a way it will mount with enough scratcher on the snow. Not straight forward, unfortunately. That being said, off trail, a tunnel cooler has been everything I'd hoped, so no matter what brand tunnel cooler you do, I say it's well worth the effort for consistent temps. I'll solve for on-trail cooling by adding back in a radiator or sticking with the original plan of using scratchers.
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@AllHatNoCattle what coolant are you running? Is it evans waterless?
Also send me an email, I will get you setup with the proper heat exchanger.
Also send me an email, I will get you setup with the proper heat exchanger.
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I am running just regular Prestone coolant. I have found it to be more readily available so I run that on my snowbike in case I ever need to "top it up".
I figured out that my thermobob thermostat was old and it wasnt opening and closing correctly. I replaced it with a new internal thermostat and this is my experience now:
- Riding in any powder the bike is near perfect temps all the time. It will sit between 160f and 180f all day without issue.
- On the trail, without scratchers I will overheat pretty quick. I have two ice scratchers now and it keeps the temp gauge right at 180 all the way down the trail
- However, even though the gauge reads 180, the clutch will lose pressure and I get excessive freeplay if I am on the trail for a while. If I stop and open up the engine blanket and throw some snow onto the clutch cover it goes away. I am not sure what is going on there. I have purchased a new clutch and will see if that solves the problem.
Other than the wierd clutch issue I have no complaints. It seems to be working fantastic.
@AllHatNoCattle Can you post an image (and any pertinent details) of your scratcher setup? (or, if you've already covered in another thread, feel free to point me there)
