bigger radiator test

I´ve just bought a pair of cheap eBay Chinese radiators. The main purpose was to have them as a spare part for a long desert and mountain raid I’m having next month. Also got a Chinese silicone hose kit, and a Trial Tech digital temperature gauge with a hose sensor.

To my surprise, the rads look really good, much better than expected for the money (good welds, thick walls, thick body, but crappy cap). Also, had some good comments about their better cooling ability due to more capacity, since they are 40mm instead of the 23mm or so from OEM rads.


I always thought this bikes run a little bit too hot, specially at low speeds or hot enviroment (desert, wind form behind, hi-reving in mud or deep sand, etc) , and I think that some extra cooling would help in engine durability, reliability and efficiency., so I decided to kill my curiosity and test them.

First installed the temperature gauge right after the engine water exit.


Then run the test with OEM rads, from a totally cold engine, one day in the morning. After that, installed the CHN rads and run the same test in the afternoon, also form a totally cold engine and almost same conditions (same spot, about same ambient temperature, etc)

The test I run was very simple, home-made-non-scientific. First the “static test”: start the bike and keep it completely idle for 10 minutes (not a single gas turn). Take temp readings every 30sec the first 5 min, then every 1 min. At minute 10, turn it off and keep reading for another 5 min. After that, the “dynamic” test: run the bike hard for 3 minutes. After stopping, read the current temp and then again 1, 3 and 10 minutes after that.



After that, installed the CHN rads and hoses, and repeat the test. (kept the OEM cup)


Here, the results. (The temperature is in Celsius, sorry Fahrenheit fans)


My interpretation and oppinion:

They cool a little more (about 2 ºC) when the bike is heating up, up to a certain temperature when them both cool the same. When riding, the also cool 2-3 ºC more. When stopped, the CHN get cold faster 4ºC).

They look stronger. Couldn´t test that yet, we´ll se after a few falls if that´s true :rolleyes:

They are heavier (rads+coolant weight like 0.5Kg more)

They don´t fit so well: the shrouds needed some hard pulling to get in place.

My general conclussion is that they seem to run a -little- better, specially when running and after stopping.

Not worth the replacement for performance reasons, but a very cheap replacement choice.

General data:

Bike: 08` WR450f with stock water pump and exhaust pipe. OEM rads non bent nor hit.

Altitude: sea level

Coolant: water with no special coolant (there´s a reason for that)

Env: 24-25 ºC, no wind, cloudy

Next step:

Try them in the desert raid.

Install a fan cooler and run the test with different coolants (i think THERE will be a difference)

Install a hi-flow water pump.

Best regards, from Argentina.

Thanks for the information. This helped me decide to buy some also

Really nice write up! :thumbsup:

That is really nice. Once my bike shows up (07 WR450) ill have to do something like this. Was thinking of putting radiator fans in.. I would like to keep the bike cool/operating temp.

I bought those for the DRZ400 that I had last. I felt the same, great product & price.

The cooling performance really doesn't improve without installing a fan(s). If the air isn't flowing, the heat isn't either.

It's not worth your time to test again with & without a fan, but I'd think the larger Chinese rads would cool better then. But since the OEM cool quite well when the air flows I just mounted a fan.

I purchased a set off ebay for 85.00. From superraduator. They work great. The cross over tube at the top of each that connects the two together did not line up. I had to tweek the pipe a little. Other than that they fit great. The plastic fit great. I have 2 hard weekend's on them already on my 2003 wr450f

These are the pictures of when i installed my ebay radiators







sweet. Nice Thermo guage btw.

Just picked up a pair for around $90 shipped. I recommend folks change out the hoses when you do this. its cheap and you are already in there.

Thanks, diekatze450, awesome write up.


I think I'll get some for my 02 KTM 400 EXC.

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