My Honda XR650L Oil Cooler Project

[SpudRider]

After finding the highest oil temperature my bike sustained without a front fender, I decided today to test a drilled fender. I drilled as many holes as I could, while still trying to maintain the structural integrity of the fender.



After mounting this fender, I actually removed it, and drilled more holes on the outside edges. Then I went for a ride on the freeway. Riding at 75-80 mph for about 30 miles, my oil temperature reached a high of 279 degrees. :roll: This oil temperature was 24 degrees higher than the 255 degrees I observed riding under similar conditions without a front fender, and I consider it unacceptable.

If I didn't fully understand before, I certainly understand now. Maximum airflow is the key to keeping oil temperatures lowest. Althought the drilled fender looks well ventilated, it is undoubtedly more than 50 percent blocked. :roll: Here are a few photographs of my bike after the freeway run.





I decided this was my final ride with this drilled front fender.



After I arrived home, I cut a large square out of the fender, and installed some 1/4-inch, galvanized hardware cloth. I'll post a photograph of the modified fender later.

The next time weather permits, I am going to make another freeway run, and this time I expect the high oil temperature will be much closer to 255 degrees than 279 degrees.

Spud

[katoranger]

Is the aluminum I sent too small? I will take that roll with to Kansas.

[katoranger]

Is there some way to make some air scoops to direct more air over the cooler?

[SpudRider]

Originally Posted by katoranger

Is the aluminum I sent too small? I will take that roll with to Kansas.

The aluminum mesh you sent me is excellent! Thank you, Allen. I decided I wanted to connect the wire mesh to the fender with small zip ties, and they won't fit through the smaller mesh. :oops: I think larger mesh might also resist getting clogged with dirt.

Here are a few photographs of my modified fender with the 1/4" hardware cloth, and the excellent aluminum mesh you sent me. As always, thank you for your help, and your generosity.





Spud

[SpudRider]

Originally Posted by katoranger

Is there some way to make some air scoops to direct more air over the cooler?

The fender sits immediately in front of the oil cooler, so I think the wire mesh should solve my airflow problem, Allen. Weather permitting, I will take a test run down the freeway this afternoon, and note the oil temperatures.

Spud

[SpudRider]

Here's a photograph of the modified fender installed on my XR650L.



I'll take a freeway run as soon as weather permits.

Spud

[SpudRider]

I got a little wet at one point, but I still made several, freeway test runs of my oil cooler today. My latest fender modification was successful. Riding the same stretch of freeway that yielded a high oil temperature of 279 degrees yesterday, my high oil temperature was 248 degrees today.

I also rode the same section of freeway that yielded a high oil temperature of 255 degrees without my front fender mounted. Today, with my modified fender mounted, I reached a high oil temperature of 253 degrees. Riding back home along this same stretch of freeway, I encountered very strong headwinds that kept my speed at 75 mph while riding wide-open-throttle. My high oil temperature under these conditions was 235 degrees.

This oil cooler installation works very well. Other than the XR650R C/S sprocket, I think this is the best modification I have made to my XR650L. I am very pleased with the current configuration of my oil cooler; at this point I don't plan to make any further changes. I will certainly report if I encounter any difficulties with this installation.

Another forum member promised to loan me his XRs Only temperature gauge next week. After riding a few miles with his oil dipstick thermometer, I will report the difference in temperature between my temperature probe located near the engine, and the oil dipstick thermometer located in the oil reservoir.

Spud

[FastDoc]

Your TTO seems to be paying for itself already. I'm interested in the comparison.

[Weldangrind]

Sounds like you've optimized it, Spud.

[SpudRider]

Originally Posted by FastDoc

Your TTO seems to be paying for itself already. I'm interested in the comparison.

I'm addicted to my TTO Temperature Gauge. The large, digital display is very easy to read at a glance. I don't know how I ever lived without this thing! I shudder to think how hot my XR650L was running before I installed this oil cooler! 8O

Spud

[SpudRider]

Originally Posted by Weldangrind

Sounds like you've optimized it, Spud.

I think so, Weld. I'm glad I spent the $95 to install an oil cooler. I'm sure fixing a dropped valve seat is much more expensive.

Spud

[Weldangrind]

Are you planning on a fan now?

[SpudRider]

I don't think I need a fan, Weld. This oil cooler dissipates heat very well, even when stationary. If you are moving even slowly, the heat transfer increases. This oil cooler is just about the perfect size for the XR650L; I think I found a winner!

Spud

[Weldangrind]

What was the original application of the cooler?

[FastDoc]

I'm now thinking of getting a TTO for my oil or my coolant on the YZ. Although I've never heard of anyone doing this on the TT forums...

Looks like cheap insurance that's for sure.

I WISH I had a cooler and gauge on my little 250 back in San Francisco. :roll: