Temperatures to that oil is exposed in an engine

[moribundman]

The question to what temperatures engine oil is actually exposed to comes up on occasion. I found this list that I copied a while ago from some site that I don't remember. Maybe someone can confirm the figures to be about right. All temps are in degree F.

Upper Cylinder Wall: 300-500
Exhaust Valve: 1200-1500
Piston Crown: 700-800
Hydraulic Valve Lifter: 250-300
Crankcase: 200-300
Top Piston Ring: 300-650
Exhaust Gases: 500-1000
Combustion Chamber: 3000-5000
Coolant Jacket: 165-230
Connecting Rod Bearings: 200-375
Main Bearings: 200-350

 

[Ray Garlington]

it was in the amsoil oil study by the "Great Bob"(http://undergrad.nova.edu/kevin/amsoilstudy.cfm. Not sure where he got it from.

 

[moribundman]

This list is spreading like the bird flu.

 

[Gary Allan]

Well, where are the colder areas

According to that ..the lowest temp that oil can attain is 200F ..and that's just when it's catching a break from the rest of the time it's at 250-350F.

There needs to be extensive qualfications.

 

[Kestas]

The list is very simplistic compared with the temperature gradations and dynamics that are occurring in an engine.

Lubrication is best evaluated by engine dyno (or real-world testing), then forensically looking at the oil and engine wear parts, rather than obsessing over what temperatures are present in the engine.

For example, what does the combustion flame temperature or exhaust temperature have to do with the oil?