Engine cooling

[hank43]

Got a new technical question:

Why do most (if not all) MC Mfgs cool just the cyl. heads, why not the entire engine? Is it because the radiator can't be that big? (No place to put it).

hank

[Mr Jensee]

Hank that is the purpose of the motor oil. Liquid cooling is for the areas of the engine that produce the most amount of damaging heat. Cylinder temps can approach a thousand or more degrees on a summer day. Without some type of system to wick off the high temperatures metal will weld itself together and the engine will seize. Cooling fins or a water jacket is needed to draw off that much heat. By comparison the rest of the engine is rather cool. engine oil flowing through it and cooled by an oil cooler or recirculating back to an oil tank is sufficient to draw away that much heat. If there was a need for greater cooling I assure you the engineers would have designed a better system for the rest of the engine transmission.

[cushman eagle]

I only have a service manual for the VXII, and it shows O-rings at the bottom of the cylinder sleeves, indicating the sleeves are cooled by water. If you look where the water manifold is located in the front of the engine,you will see it is below the cylinder head.The only other water cooled motorcycles I have experience with were my dads v45 and gl1100, which were both cooled with water around the cylinders.I just looked at the water passages in a gl1000 I have to work on now and it also has water around the cylinders.

[gearheadfla]

The 1st clue on the XII is no cooling fins on the engine at all, it is water cooled, no air cooling. Heck, air can't even get to the engine with all that tupperware.

[debron]

Hank has a 1700 V-Twin Voyager. . .

[Mr Jensee]

My post still stands for all liquid cooled engines.