My Honda XR650L Oil Cooler Project
 

The Honda XR650L employs an air cooled engine with a dry sump oil system. The oil pump sends oil to an external reservoir in the frame, and the oil is cooled somewhat by exiting the engine for a while. :) However, the smaller, Honda XR250R and Honda XR400R also came equipped with external oil coolers, as well as the dry sump engine. Honda declined to install an external oil cooler on the XR650L, and installed air scoops on the fuel tank, instead. :roll:

http://i442.photobucket.com/albums/q...foorRes020.jpg

The stock fuel tank only holds 2.8 gallons, so most riders quickly buy a larger, aftermarket fuel tank. ;) However, none of the aftermarket fuel tanks will accommodate the stock air scoops. :( Therefore, the XR650L can overheat if run at high rpms for extended periods of time. Therefore, many XR650L owners install oil coolers on their bikes.

Some people install an XR400R oil cooler on the XR650L. However, a proper installation of the XR400R oil cooler requires welding studs onto the oil reservoir. :( The XR400R oil cooler also requires a lot of special, oil hose fittings, so it is an expensive solution. :roll: In addition, this oil cooler is located in close proximity to a lot of wires and cables on the XR650L, which can easily be damaged by the heat. :( Therefore, I ruled out installing an XR400R oil cooler. ;)

Two individuals also manufacture oil coolers for the XR650L. However, I believe both are vulnerable to damage, and both are fairly expensive. Therefore, I decided to design my own oil cooler. Here is my preliminary design. I am going to add a digital temperature gauge to my final installation, as soon as I receive shipment of the NPT brass fittings I ordered. :)

http://i442.photobucket.com/albums/q...lumbing012.jpg

http://i442.photobucket.com/albums/q...lumbing022.jpg

http://i442.photobucket.com/albums/q...lumbing016.jpg

http://i442.photobucket.com/albums/q...lumbing025.jpg

Spud :)

If you're interested in learning more about the XR400R oil cooler installation for the XR650L, you might enjoy reading the following thread. :)

http://www.4strokes.com/forums/topic.asp?TOPIC_ID=22902

Two individuals also manufacture oil coolers for the XR650L. Here are links to their vendor threads describing their oil coolers. :)

http://www.advrider.com/forums/showthread.php?t=652313
http://www.advrider.com/forums/showthread.php?t=578914

My oil cooler will cost much less than half the price of any of these oil coolers. I also hope my oil hoses, oil hose fittings, cables, and electrical wiring will be less vulnerable to damage.

Spud :)

Excellent idea, Spud! I wish that the XR250R came with a cooler, but it did not. Only the XR400 came with the steering neck cooler. My cooler is limited to the frame tube acting as a heat exchanger.

I have not yet plumbed my oil cooler into the stock oil lines. The weather is cool, and I am also awaiting shipment of my NPT brass fittings. Therefore, I intend to test my placement of the oil cooler by riding the bike with the oil cooler unplumbed. ;) For the final installation I will also need to cut some holes in the front fender to allow good air flow to the oil cooler. ;) However, I don't plan to perforate my front fender until the muddy part of the riding season is past. ;)

Spud :)

Thank you, Weld. :) I guess some early models of the XR250R didn't come with an oil cooler. However, the 1990 model year did have an oil cooler.

http://www.cheapcycleparts.com/model...ssemblies/7847

http://www.xlv.ch/Bilder/xr/zubehoer/Oil-Cooler_1.jpg

Some XR650L owners install the smaller, XR250R oil cooler. However, this oil cooler requires the same placement as the XR400R oil cooler, and entails the same disadvantages. ;)

http://www.4strokes.com/forums/topic...02&whichpage=5

Spud :)

Here's another link showing the installation of the XR250R oil cooler on an XR650L motorcycle. :)

http://www.advrider.com/forums/showt...7#post16044037

http://i704.photobucket.com/albums/w...r_2009/005.jpg

Spud :)

Here's another interesting link concerning the XR250R oil cooler. :)

http://www.xlv.ch/XR/Generalinfos/Oil-Cooler.html

I considered installing this oil cooler, but I think my design has advantages over the XR250R oil cooler. My oil lines are shorter, and less likely to damage other parts of the bike with heat. My oil cooler has a much larger surface area. Also, it is increasingly difficult to find used, XR250R oil coolers for sale. Therefore, my oil cooler installation will undoubtedly cost less than an XR250R, oil cooler installation. ;)

Spud :)

Excellent work, spud!!

I decided to design my own oil cooler.

I love it Spud!

I was going to suggest a fender-ectomy or fender-otomy. Maybe a wide opening with a screen or mesh of some sort to keep rocks from breaking an oil line. Maybe a 'dry' and 'wet' season fender? Nothing wrong with running a full fender in the wet season as it's by it's very nature going to be cool enough AND even with reduced airflow to the cooler it will not be any worse than stock.

It stinks Honda cheaped out on this longevity increasing feature.

My 1996 XR250L did not have a cooler and cracked the head at 25,000 miles, I think due to overheating. I frequently ran that poor thing at 65-80 MPH on the San Francisco Bay Area freeways all year long...

Thank you, Jim. :)

Spud :)

Thanks for the good tips regarding "winter" and "summer" front fenders, Doc. :) Indeed, I plan to install wire mesh over the holes in the front fender, as shown in the photograph below. ;)

http://i1006.photobucket.com/albums/...t/IMG_0465.jpg

Can anyone recommend a good size wire mesh, and a good place to purchase it? I guess I will start looking at the local ranch supply stores, Home Depot, and Lowes for suitable material. :)

I didn't research when Honda implemented the oil cooler for the XR250R. I assumed Honda added the oil cooler in later models, but I guess Honda eliminated the oil cooler for the later models, as a cost cutting measure. :roll: Hondas are still good motorcycles, but "Mother Honda" makes a lot of decisions that way. ;)

XR650L engines will drop valve seats when they get too hot. 8O I'm hoping my oil cooler will allow me to gear up my XR650L, and make some freeway runs at high rpms later this year, without fear of toasting the engine. ;) I am adding a Trail Tech TTO Temperature Gauge to my oil line so I can constantly monitor oil temperatures. :)

Spud :)

That mesh looks like what is put up to keep squirrels out of places. Problem is that you may have to buy a roll of it. Also called hardware cloth I think. Check local hard stores.

I think I may have some galvanised mesh. I can send you a chunk of it.

Thank you for your gracious offer to help, Allen. :D I will check out my local options, first. ;) I was thinking I would like to get a finer mesh than the one shown in the photograph. Perhaps I can get a scrap piece of mesh from Home Depot. ;) As you can see, I don't need a very large piece. :)

Spud :)

Check with the local places that do window screens.

Thank you for the good tip, Allen! :D

Spud :)

I haven't examined one of these Polisport fenders, but they might do the trick without the mesh and holes: Polisport Front Fender with RADS Scoop You certainly can't beat the price, and I'm sure that the CRF version can be made to fit your bike.

The galvanized material will eventually rust, so I'd look to a local metal shop for stainless. I have a piece of woven stainless that I intend to use for an exhaust screen, and I think it came from Metal Supermarket. Perhaps you have a shop like that.

That's an interesting fender, Weld. Thanks for providing the information, and the link! :D I wonder if the radiator scoops would deflect enough air to cool the oil? My oil cooler is located directly behind the fender. Brother Andy has warned me the heat from the oil cooler might melt my front fender if I am not careful. 8O I was thinking the holes in the fender would help prevent this from happening. :?

Spud :)

This afternoon I found some 1/8", hardware cloth at the local, CAL-Ranch store. It is galvanized, but it only costs $4.99 per running foot; the roll is 3 feet wide. The helpful gentlemen at the store said they would see me 1/2-foot of the mesh, so I could get enough screen to cover 6 fenders for $2.50. :) However, I think I could also get aluminum, plastic, or fiberglass mesh from some other source. What do you guys think?

Spud :)

Plastic that looks like expanded metal would be very good for your project, although I'm not sure where to find it.

For the $8.00 investment, it would be interesting to learn if the scoops would direct air to the cooler. You'd get a good idea of how the air would flow once you installed it.

I can't tell from the photograph, but I don't see how the the air scoops can accommodate the fork boots on my XR650L. :? If the fork boots fit inside the fender, won't they block the air flow? Thank you for providing the interesting link to that fender, Weld. :D However, I must admit, I also don't care for the looks of that fender. :lol:

I can buy a number of vented fenders. Here's an Acerbis vented fender.

http://a248.e.akamai.net/origin-cdn....13650227-2.jpg

Here's a Polisport vented fender.

http://www.rockymountainatvmc.com/im...1288600001.jpg

However, I really want to cut air holes in the stock fender. If I screw up, I can always buy another fender. ;) Also, this afternoon I just got the front fender shimmed properly to clear the oil cooler, so I don't want to repeat this process all over again with another fender. ;)

Spud :)

Nice job..
I have made a cooler for my XT
getting it on is a winter job..
The Xt is dry sump so I will pumb
it into the return line back to the
oil tank in the frame..

http://img600.imageshack.us/img600/7246/ssa41851.jpg
By petenz at 2012-03-29

pete, that's really cool! Where did you find a heat exchanger like that?

Thank you, Pete. :) I am using the same plumbing method as you. ;) The oil pump will feed oil into the bottom line of my oil cooler. After the oil exits the top of my oil cooler, it will flow into the oil reservoir in the frame. I plan to install a digital temperature gauge in the oil line before it feeds into the oil cooler, so I can monitor the oil temperature directly after the oil exits the engine. ;)

Spud :)

I made it...
2 peices of 40mm solid 200mm long..
bored a 6.5mm hole though them then
put the fins in with a 3mm parting tool
leaveing a 12mm dia section up the centre
14mm deep fins..then mill flats on so they
can fit togeather

You've got skills! Did you make that on a milling machine? I can see the fitting that joins the two reservoirs; does fluid fill one cylinder and then dump into the other?

Most of its made in a lathe apart from the flats that were milled..
oil goes in one section flows across though the brass nipple into
the other sction then out... It was only going to be one section but
I had the room so made a second section in the end..

I have a lathe & mill in my home shop..

http://img822.imageshack.us/img822/5915/ssa41854.jpg
By petenz at 2012-03-29

I found some plastic, 1/8" mesh at the following website. :)

http://www.countryporch.com/darice/view.asp?item=33400

What size mesh do you guys think I should get? Perhaps 1/4" mesh is less likely to clog with mud?

Spud :)

I can get "plastic canvas," or vinyl weave at a crafts store. ;) Do you think 7 holes per linear inch is too small?

http://en.wikipedia.org/wiki/Plastic_canvas

Spud :)

I think that the smaller holes will quickly clog. One thought I had. Drill a stock fender with alot of 3/16 holes. Maybe 1/4". I don't think anything smaller than a 1/4" will hurt anything.

Simply genius! Thanks for sharing that with us. I might think about a similar project for my XR.

Too small clogs the holes, too large allows the mud to clog the cooler. it might just take some experimentation.

I still like the cooling ducts. :)

I like that idea a lot, Allen! Thank you. :D

I think it would be pretty hard for any sizeable rock to make it past a 1/4" hole in the fender. :D Also, I can drill 3/16" holes, and enlarge them later if I wish. In addition, I don't need to worry about purchasing and attaching mesh to the fender, and I don't need to worry about rusting steel. ;)

I am considering arranging the holes in rectangular blocks, as shown in the photograph below.

http://i1006.photobucket.com/albums/...t/IMG_0449.jpg

If I don't like the way the holes perform, I could always cut out the rectangles later, and install mesh. :idea: What do you guys think?

Spud :)

The radiator duct fender is indeed, a "cool" idea. ;) Thank you for bringing it to my attention, Weld. :D I wish I could see one in person; it would help me decide if I like the way it looked on my XR650L motorcycle. ;)

http://images.motorcycle-superstore....RADS-Scoop.jpg

I think I now realize how the scoops work! :idea: The forks pass the fender in the middle of the scoops. However, the forks don't completely block the air scoops; the forks merely reduce the size of the hole in the air scoops. The air exits the rear of the scoops, and is deflected downward toward the radiators on either side of the frame. ;)

It would appear the size, and placement of the fork scallops is critical. I'm not sure one of these fenders designed for a Honda CRF would fit my XR650L. :?

Spud :)

A top tip for you Spud.

Use a STEP drill from HF to drill the holes from the inside. This will self-deburr and leave a perfect result.

I continue to like FastDoc's idea of employing "summer" and "winter" fenders. Instead of installing some type of velcro "bra" to the oil cooler in colder weather, I could just install the "winter" fender which lacks the air holes. ;)

Speaking of oil cooler "bras," what is a good material for this purpose? My oil cooler is a 4-inch square. Therefore, if I had a rectangular piece of material 4" wide by 10-1/2" long, I could secure this material around the oil cooler with a velcro strip. ;)

I thought about installing a Jagg oil bypass, but my hose lines are too short to accommodate one of these units. ;)

http://www.jagg.com/by-pass.htm

http://www.jagg.com/images/accessori...-300pxwide.jpg

Spud :)

As always, thanks for the good tip, Doc. :) I see the step drills bits are on sale at Harbor Freight. ;)

http://www.harborfreight.com/catalog...tep+drill+bits

Spud :)

Just wrap some tape on the bit at the correct depth so you don't cut too big a hole.

Used in plastic it gives a very nice result.