I finally got my custom aluminum radiator project finished up. I had decided to replace the original radiator with an aluminum one for 3 reasons. 1. The plastic endcaps on mine were bubbling from heat which scared me to be quite honest 2. The plastic mounting brackets are very flimsy and I could see them breaking out in the wild at the worst possible time in the event of a bad nap. 3. I really don't like the integrated thermostat and wanted some thing easier to service and tune. So.... I contacted Fontana Radiator here in SoCal and they were up for building me a custom one as they build similar custom radiators for race bikes. I already knew I was going to use a thermostat housing from Thermo Bob and had contacted him about the application. The radiator build turned out to be more work than either of us had planned on and required some rework on the mounting tabs to get things right. In retrospect I should have built them a bench fixture to work against so the mounting points etc. came out dead nuts. Anything custom is a process you work though. In the end it came out as I expected. Here's a comparison of the OEM radiator and the aluminum one. And finished up on the bike This shot shows the new T-stat housing and extra connector to create a return loop. In this design the coolant still circulates in the engine even when the thermostat is closed which prevents severe hot spots from forming while the coolant warms up. To access the T-stat I only have to drain the coolant and remove the 4 bolts on the top of the T-stat housing and I can R/R the T-stat. The total cooling capacity has been increased by about 25% or so and at anything from about 20 mph above it will sit right on the thermostat temp. I have a choice of thermostat temps and I chose a 80C. I have a 85C also and can get a 90C. As most of my riding is in hotter temperatures I'll probably leave the 80C T-stat in. The indicated temp in the dash is almost exactly halfway across the total bars. It was a big project and not cheap, but I really like my Husky and intend to keep it for quite a long time. The radiator setup was the only part of the bike (except the original air filter) that I really wasn't comfortable with. Now that's done..... and I can ride without worrying about my T-stat going out and not being able to fix it or any other aspects of the cooling system.
Is it a "plug and play" alternative? Does the radiator builder have the capacity to run off a few more? Maybe you could recoup some of your cost by seeing if there is enough demand from here or Advrider forum to warrant a production run for other TR650 owners.
The cost for this project was $475 for the radiator and about $125 for the thermostat housing kit. The price for the radiator included a lot of measuring etc. It could be a plug n play deal but I'd need to make up a welding fixture for the radiator guy to work to so they would be a drop-in. This one was completely custom, the prototype as it were. I wonder if there isn't another aluminum radiator from a different bike that might make it easier, not sure. There are a few mounting brackets associated with the radiator on this bike which makes it more complicated than some others. If you don't care about the plastic rad mounting brackets the easier approach is to just have some aluminum header tanks fabbed up and welded on the OEM core. Then use the external T-stat setup. If there was enough interest I could see what it might cost to make a batch and see about making the welding jig. I can make the fixture, it's just time and materials. I have my original OEM radiator to use as a pattern. The building has capacity to make them in small batch numbers.
Danketchpel, did you or the radiator guy check the flow rate capability of the OEM radiator and the replacement ?
No, the flow rate for the new one is equal or greater than the OEM unit. The core is thicker than the stock unit, the header tanks are deeper, the inlet/outlet are equal in diameter. It's setup to be a cross flow. I can tell you from riding it that it will sit on the t-stat temp at anything over 20 mph.
Thanks, discussing radiator and behaviour here and visual indications in dash has made me question whether the OEM Husky radiator is lower flow rate than the ones on the BM 650GS and G650X as there are some oddities in the Husky compared to the others which mostly have smaller fans
It would be an interesting comparison but I just didn't make the effort or have the setup on hand to do so. I do question the OEM radiator in terms of flow pattern and possibly even flow itself given how shallow the left hand header tank is. The OEM flow path is hot in the bottom cold out the top. This is pretty much reverse of many other units and how mine is setup. Mine has the hot come in the top flow across the top (there's a baffle plate in the right header tank) then across the bottom and out down to the pump. I discussed this with the radiator guy and that was his suggestion. This is also flow path for most cars/trucks. Another thing, the total coolant capacity is quite a bit more, maybe 2/3 as much considering how much extra coolant I had to add. I have found this has really increased the thermal inertia, meaning it takes longer to for the temp to rise once the air flow stops, say at an extended stop. I'd say it's nearly twice as long as the stock setup. I do think that if I were riding in colder average temps I might put in a lightly hotter thermostat, maybe a 85C or possibly 90C. I think the benefit here is boiling off the water condensate in the oil. I have seen the results of having the oil not get hot enough in the winter months on my Moto Guzzi. When I pull the valve covers off to adjust the valves in the winter there is always a white "sludge" buildup where it's cold on the covers. It is basically water trapped in oil. During the summer this goes away. It's quite typical for the Guzzi 1200 engine as it's somewhat over cooled for cold temps, but just about right for hot weather.
Good work, Danketchpel. A plug and play, particularly if the price came down a bit would be an attractive addition. The only significant issue I have had with the bike has been cooling related.
For your info the TR650 radiator is exactly the same as the Radiator used in the Nuda 900, an engine which runs a lot hotter. The Nuda radiator only just copes here in the Philippines as does the TR650, so I have removed the Thermostat from both of mine and all is good.
If you make a small batch, I would be interested. Mine the mounting tabs are cracked, using a B&G Racing guard to hold it in place should they break completely.
