My Honda XR650L Oil Cooler Project

[SpudRider]

Originally Posted by Weldangrind

What was the original application of the cooler?

I bought a transmission oil cooler. It is made of thick aluminum plates, and it is tough as nails!

http://www.bakerprecision.com/trucool.htm

I bought the SmallPS oil cooler, for $29.95.

Spud

[SpudRider]

Originally Posted by 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:

I wish Honda hadn't removed the oil cooler from your XR250. :roll: My XR650L has several known problems; I have tried to resolve all of them. Here are the known issues with the XR650L.

Extended, high-rpm riding overheats the engine, and the bike drops valve seats.
Lack of cush drive on rear wheel destroys countershaft.
Subframe cracks with heavy loads.
AC CDI unit overheats and fails.
Shift lever can puncture stator cover after falls to the left.

To prevent engine overheating, I installed my oil cooler. I saw a 31 degree drop in oil temperature yesterday merely by cutting a hole in the front fender. This temperature reduction was noted after the oil cooler was installed with a drilled fender! Therefore, the temperature drop from stock configuration must be even higher. 8O

To protect my countershaft, I installed an XR650R C/S sprocket, which has 60 percent more contact area with the countershaft.

I reinforced my subframe with triangulated struts, and removed the battery box which weighs over 10 pounds.

I learned to repair my CDI unit. I then relocated the CDI unit to the airbox, where it is subjected to much less vibration, and is cooled by the air flowing into the carburetor.

I reinforced the stator cover with an aluminum plate.

Honda knows about all these issues, but they haven't improved the bike since it was introduced in 1993. :roll: However, Honda did remove 3 grease zerks from the progressive shock linkage, and also removed the oil drain plugs from the forks! 8O

Spud :roll:

[SpudRider]

Originally Posted by 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:

Indeed, you can get the TTO gauges for $35, and they are excellent insurance.

http://trailtech.net/tto_temperature.html

Just measure the diameter of your radiator hose, and select the proper temperature probe.

Spud

[SpudRider]

Today a local, XR650L owner loaned me his XRs Only temperature dipstick. Therefore, I was able to take a ride and compare the oil temperatures between my TTO Temperature Gauge and the oil reservoir.



As you can see in the following photograph, the oil cooler receives an unobstructed airflow over the front wheel, and below the front fender.



The above and below photographs also reveal the oil lines are well protected by the forks and their high location inside the outer edge of the fuel tank.



The motorcycle must warm up a bit before the temperature of the oil in the reservoir stabilizes. However, after the temperature stabilizes, the oil temperature in the reservoir is 25 degrees cooler than the oil temperature exiting the engine, when the bike is idling. After riding about 50 miles, I took the following photograph of oil temperatures with the engine idling.



As you can see, the TTO temperature probe located in the oil line before the oil cooler shows a temperature of 225 degrees, while the oil dipstick thermometer shows a temperature of 200 degrees.

After the engine is turned off, the temperature of the oil in the external lines and cooler quickly drops 30 degrees in several minutes. In contrast, the oil in the reservoir cannot radiate the heat as well, and the temperature remains elevated. I took the following photograph about 3 minutes after turning off my bike’s engine. The oil temperature in the cooler has dropped to 94 degrees, but the oil in the reservoir is 125 degrees.



If you wait longer before starting the engine, the temperature of the oil in the external lines and oil cooler drops even more. After stopping to take some photographs and enjoy the scenery, I recorded the temperature difference in the following photograph. The temperature at the TTO probe is 97 degrees, while the temperature in the oil reservoir is 160 degrees.





When pushing the bike to it’s maximum oil temperature, the temperate at the TTO probe and the oil reservoir are identical. Indeed, this must be the case. If the temperature of the oil in the reservoir is lower, the reservoir temperature must continue to rise until the two temperatures are equal, or a maximum temperature cannot be reached.



During most of my ride today, the oil temperature at the TTO probe was 10 to 15 degrees hotter than the temperature at the oil dipstick. The temperature difference is greatest at idle and low engine rpms. The temperature difference decreases as the engine load and engine rpms increase; the two temperatures are identical at the maximum oil temperature of the system.



After exited the off ramp from an extended, wide-open-throttle run on the freeway, the oil cooler quickly drops the temperature of the oil it sends to the reservoir. Even after riding about ½ mile, and pausing at several stop lights, the following photograph shows my cooler dropped the temperature of the oil in the reservoir 28 degrees before I parked the bike outside Wal-Mart. The oil coming from the engine is 253 degrees, but the oil inside the reservoir is 225 degrees.



Please note, in this instance, reading the dipstick thermometer alone would be deceiving, since the oil coming from the hot engine is still 253 degrees. It takes a short time for the cooler oil in the reservoir to quench the hotter oil still inside the engine.

I can easily keep oil temperature below 240 degrees if I ride at 65-70 mph on the freeway. When I push the bike continuously, wide-open-throttle for 40 miles or more, I can get a maximum oil temperature of 258 degrees, before the temperatures from both thermometers equalize. Running less than wide-open-throttle will always show the TTO temperature probe running at least 5 degrees hotter than the dipstick thermometer in the oil reservoir.

Spud

[Weldangrind]

Another beautiful day in Spudland.

That's excellent empirical data. The only remaining variable is the accuracy of both instruments. If you were so inclined, you could place both probes in boiling water to compare the readings. Using one gauge, right or wrong, allows you to quantify changes, whereas two gauges mess up your data if they don't agree.

I'm not trying to convince you to verify the accuracy of both instruments, it's just a point of trivia.

[FastDoc]

Since the two instruments correlate appropiatly under all circumstances and they have different mechanisms I bet they are right on. Still to put the dipstick one in boiling water would be an easy test. I'd probably try it. :wink:

[SpudRider]

As always, thank you for your replies and helpful input, gentlemen.

The TTO temperature gauge was correctly reading the heat of the ambient air in my home before I installed it. Of course, I now don't want to remove it from my oil line.

The XRs Only temperature gauge has been repeatedly tested, and is know to be accurate. However, I think I will test this particular probe in boiling water to verify it is still accurate.

Spud

[Weldangrind]

Yep, hard to beat the latent heat of vaporization with water. As long as it's boiling, it will always be the same temperature. That's where I prefer the Metric system; freezing is zero and boiling is 100. Super easy to remember.

[SpudRider]

Originally Posted by Weldangrind

Yep, hard to beat the latent heat of vaporization with water. As long as it's boiling, it will always be the same temperature. That's where I prefer the Metric system; freezing is zero and boiling is 100. Super easy to remember.

I prefer the metric system as well. I wish the United States had switched over to the metric system a long time ago. :roll:

Spud

[Weldangrind]

We're quite bi-polar in Canada. How much do you weigh? 200lbs. How fast do you drive on the freeway? 110km/h. How tall are you? 6 feet. How much milk is in a big plastic jug? 2 litres. It goes on and on.

The original Imperial system had some base-10. There are 10 pounds of water in an Imperial gallon.

I'm sure that SAE machinists would have preferred the Metric system over thousands of an inch. It's really the same concept, without any fractions.

[davidsonsgccc]

im a machinist and i have worked with metric and standard. i prefer standard but i have spent a lot of time working in thosandths i always have to be careful with metric prints it is easy to goof. tht being said if i had grown up using metric more i probably would prefer it over standard.

tolerances are harder to make in metric so maybe i would still like standard the best. to me fractions are easy numbers to shoot for. most people around here fabricate rough parts holding fractional dimensions then machine them to decimal tolerances. most of the prints i see give fractions with a -/+ 1/16 tolerance but decimal is usually +/- .001-.005 depending on parts or maybe .0005 or .0127 if metric

[Weldangrind]

Feel that? The thread is starting to drift...

I grew up with the Metric system, but that doesn't mean I prefer it, especially when it comes to lumber and framing. Also, we deal so closely with the States, that it makes sense to speak both systems. Where it becomes confusing is for older guys in Canada who learned the Imperial system; gallons are different between the US and the UK.

/hijack

[davidsonsgccc]

sorry about the drift attempt lol. i do have one question though do your tape measures usually read in metric or standard or is both equally excepted.

[FastDoc]

Originally Posted by davidsonsgccc

sorry about the drift attempt lol. i do have one question though do your tape measures usually read in metric or standard or is both equally excepted.

Nah.

It's what we do.

Now what about North Korea... :roll:

[Weldangrind]

Originally Posted by davidsonsgccc

sorry about the drift attempt lol. i do have one question though do your tape measures usually read in metric or standard or is both equally excepted.

I've never had a Metric-only tape, but I've had several that read both. I also have tapes that are only in inches. All of my vernier calipers read both scales.