pamcopete
Ride.Enjoy.Life is Simple
Well, it's getting hot out there, so time to revisit one of our favorite and most emotional subjects, and one that remains a mystery......why does the right side cylinder generally run hotter than the left?
Friendships have been lost and small businesses created over this subject. Because there is no agreed to cause for the phenomena, opinions rule, and we all know what that leads to...everybody has one, just like a certain part of the anatomy.
So, here goes:
I recently installed an oil cooler on my '81/H. This is a full flow cooler mounted in a good position to do some cooling, and its operation is verified by observing my oil pressure gage, and by touching the cooler after a run for a subjective "feel".
Now, just for the hell of it, I have started to check the cylinder temperatures after each run with my infrared thermometer, and guess what? The temperatures on each cylinder are the same!
Now, this is still early to draw a conclusion, but here is my theory:
Yamaha engineers designed the oil flow to restrict somewhat the oil that squirts on the right cylinder, because they wanted to save pressure and volume for the overhead cam and left cylinder, which are downstream of the right cylinder. (The right cylinder is first in line for the oil from the screen)
Well, perhaps they went too far, and the right cylinder does not get enough oil for lubrication as well as cooling. The left cylinder, even though it is downstream of the right, has a larger opening for the oil squirter so it's just fine.
Now, the oil cooler cools the oil down, and as a result, there is slightly higher pressure as well as the oil enters the engine and heads straight for the right cylinder. Cooler oil under more pressure!! What a concept for a cooler running cylinder!
Although both cylinders read the same, the temperature is still up around 240 to 255.
So, we haven't heard from XSJohn for a while, but this is his chosen area of expertise, so I'm sure this little post will get his attention.
Friendships have been lost and small businesses created over this subject. Because there is no agreed to cause for the phenomena, opinions rule, and we all know what that leads to...everybody has one, just like a certain part of the anatomy.
So, here goes:
I recently installed an oil cooler on my '81/H. This is a full flow cooler mounted in a good position to do some cooling, and its operation is verified by observing my oil pressure gage, and by touching the cooler after a run for a subjective "feel".
Now, just for the hell of it, I have started to check the cylinder temperatures after each run with my infrared thermometer, and guess what? The temperatures on each cylinder are the same!
Now, this is still early to draw a conclusion, but here is my theory:
Yamaha engineers designed the oil flow to restrict somewhat the oil that squirts on the right cylinder, because they wanted to save pressure and volume for the overhead cam and left cylinder, which are downstream of the right cylinder. (The right cylinder is first in line for the oil from the screen)
Well, perhaps they went too far, and the right cylinder does not get enough oil for lubrication as well as cooling. The left cylinder, even though it is downstream of the right, has a larger opening for the oil squirter so it's just fine.
Now, the oil cooler cools the oil down, and as a result, there is slightly higher pressure as well as the oil enters the engine and heads straight for the right cylinder. Cooler oil under more pressure!! What a concept for a cooler running cylinder!
Although both cylinders read the same, the temperature is still up around 240 to 255.
So, we haven't heard from XSJohn for a while, but this is his chosen area of expertise, so I'm sure this little post will get his attention.
