Originally Posted By: used_0il
I think I know now why you said that, for an engine
oil to act like a multi-grade, it must contain VIIs.
Are the following statements true?
The thicker the oil film, the lower the shear rate
and fluid friction.
A mono-grade oil would heat up less than a VII containing
multi-grade oil during it's duty cycle in the bearing space.
VIIs were fully activated at 120C, but lost viscosity due
to temporary shear under stress.
The Illinois Central was purchased by www.CN.ca
Some of the older VII's did shear under mechanical stress, but the newer ones have minimal shear over their lifetimes, and what molecules do shear, recover quickly.
An oil does not necessarily have to have VII's in order to be a multi-grade, since the right mix of base oils can accomplish that.
VII's work at all temps becoming more active as the temp rises.
Off-Topic re: ICRR:
When just out of HS I had my FCC license and worked for a Motorola Service Center doing communications work for business radios, police radar, climbing towers, installing antennas, some broadcast work, etc.
We had a contract with ICRR and one of my responsibilities was to go on the road and track down bad radios along the right-of-way and in locomotives. My territory was W. Mo, Ill., Indiana, Kentucky. One of the most enjoyable jobs I ever had.
I think I know now why you said that, for an engine
oil to act like a multi-grade, it must contain VIIs.
Are the following statements true?
The thicker the oil film, the lower the shear rate
and fluid friction.
A mono-grade oil would heat up less than a VII containing
multi-grade oil during it's duty cycle in the bearing space.
VIIs were fully activated at 120C, but lost viscosity due
to temporary shear under stress.
The Illinois Central was purchased by www.CN.ca
Some of the older VII's did shear under mechanical stress, but the newer ones have minimal shear over their lifetimes, and what molecules do shear, recover quickly.
An oil does not necessarily have to have VII's in order to be a multi-grade, since the right mix of base oils can accomplish that.
VII's work at all temps becoming more active as the temp rises.
When just out of HS I had my FCC license and worked for a Motorola Service Center doing communications work for business radios, police radar, climbing towers, installing antennas, some broadcast work, etc.
We had a contract with ICRR and one of my responsibilities was to go on the road and track down bad radios along the right-of-way and in locomotives. My territory was W. Mo, Ill., Indiana, Kentucky. One of the most enjoyable jobs I ever had.