Higher viscosity oil
09-04-2015, 04:35 AM
#1
Drifting
Thread Starter
Higher viscosity oil
A general Corvettes question , not only a C4.
At what point or what HP level Do we need to move to a higher viscosity oil ?
a 5w30 is recommended for stock LT1 , after what mods I need higher than that ??
I'm not sure if the question is clear or sounds weirdo lol
At what point or what HP level Do we need to move to a higher viscosity oil ?
a 5w30 is recommended for stock LT1 , after what mods I need higher than that ??
I'm not sure if the question is clear or sounds weirdo lol
09-04-2015, 07:47 AM
#2
Safety Car
As far as I am concerned you can stay with the 5w30 if the bearing clearances are still all stock. Usually people switch to heavier oils if they have opened up the factory clearances (For high RPM usage) and have lower oil pressure as a result. The heavier oil will increase the oil pressure to an acceptable level.
The real purpose of oil is to prevent metal to metal contact by keeping an oil film between the rotating parts that prevents them from rubbing on each other. Some heavier weight oils may have a stronger oil film but that is not true in all cases so you really need to understand the properties of the oil you are using before you decide to switch to something else. The second purpose of oil is to remove heat from the bearing surfaces and larger bearing clearances allow more oil to move through the bearing which takes away more heat. So if you open up the clearances to allow more oil flow you may need a heavier oil to keep pressure up to an acceptable level. That being said a heavier oil does not flow as well as a thinner oil so it may not remove as much heat from the bearings as a thinner oil would have.
The real purpose of oil is to prevent metal to metal contact by keeping an oil film between the rotating parts that prevents them from rubbing on each other. Some heavier weight oils may have a stronger oil film but that is not true in all cases so you really need to understand the properties of the oil you are using before you decide to switch to something else. The second purpose of oil is to remove heat from the bearing surfaces and larger bearing clearances allow more oil to move through the bearing which takes away more heat. So if you open up the clearances to allow more oil flow you may need a heavier oil to keep pressure up to an acceptable level. That being said a heavier oil does not flow as well as a thinner oil so it may not remove as much heat from the bearings as a thinner oil would have.
09-04-2015, 09:08 AM
#3
Team Owner
A good quality full synthetic 5W-30 oil will work fine for stock engines and even with engine modifications that will generate 400+ HP. And probably more than that.
09-04-2015, 09:58 AM
#4
Instructor
Theres an interesting white paper by a claimed Phd originally(?) posted on a Ferrari site that makes the case that lubrication occurs because of flow, therefore, high flow oil pumps, not hi pressure are the way to go. It also speaks to using as low a SAE weight oil as feasible to facilitate flow( especially at startup) and heat removal.
As always, if its on the Internet, it must be true. Right?
As always, if its on the Internet, it must be true. Right?
09-04-2015, 10:17 AM
#5
Theres an interesting white paper by a claimed Phd originally(?) posted on a Ferrari site that makes the case that lubrication occurs because of flow, therefore, high flow oil pumps, not hi pressure are the way to go. It also speaks to using as low a SAE weight oil as feasible to facilitate flow( especially at startup) and heat removal.
09-04-2015, 10:25 AM
#6
Team Owner
Pro Mechanic
Now days, we've got 600+ hp/600+ tq OEM motors running on OEM recommended 5w-30. I don't feel that "hp" is the determining factor....I agree with bjankuski that clearances are the more important factor.
09-04-2015, 12:31 PM
#7
Melting Slicks
Theres an interesting white paper by a claimed Phd originally(?) posted on a Ferrari site that makes the case that lubrication occurs because of flow, therefore, high flow oil pumps, not hi pressure are the way to go. It also speaks to using as low a SAE weight oil as feasible to facilitate flow( especially at startup) and heat removal.
As always, if its on the Internet, it must be true. Right?
As always, if its on the Internet, it must be true. Right?
09-04-2015, 05:01 PM
#8
Drifting
Thread Starter
As far as I am concerned you can stay with the 5w30 if the bearing clearances are still all stock. Usually people switch to heavier oils if they have opened up the factory clearances (For high RPM usage) and have lower oil pressure as a result. The heavier oil will increase the oil pressure to an acceptable level.
The real purpose of oil is to prevent metal to metal contact by keeping an oil film between the rotating parts that prevents them from rubbing on each other. Some heavier weight oils may have a stronger oil film but that is not true in all cases so you really need to understand the properties of the oil you are using before you decide to switch to something else. The second purpose of oil is to remove heat from the bearing surfaces and larger bearing clearances allow more oil to move through the bearing which takes away more heat. So if you open up the clearances to allow more oil flow you may need a heavier oil to keep pressure up to an acceptable level. That being said a heavier oil does not flow as well as a thinner oil so it may not remove as much heat from the bearings as a thinner oil would have.
The real purpose of oil is to prevent metal to metal contact by keeping an oil film between the rotating parts that prevents them from rubbing on each other. Some heavier weight oils may have a stronger oil film but that is not true in all cases so you really need to understand the properties of the oil you are using before you decide to switch to something else. The second purpose of oil is to remove heat from the bearing surfaces and larger bearing clearances allow more oil to move through the bearing which takes away more heat. So if you open up the clearances to allow more oil flow you may need a heavier oil to keep pressure up to an acceptable level. That being said a heavier oil does not flow as well as a thinner oil so it may not remove as much heat from the bearings as a thinner oil would have.
Theres an interesting white paper by a claimed Phd originally(?) posted on a Ferrari site that makes the case that lubrication occurs because of flow, therefore, high flow oil pumps, not hi pressure are the way to go. It also speaks to using as low a SAE weight oil as feasible to facilitate flow( especially at startup) and heat removal.
As always, if its on the Internet, it must be true. Right?
As always, if its on the Internet, it must be true. Right?
Great , thanks guys. I have a better understanding about this now.