Originally Posted by Davis
good to know! Measure the pan? or where is that temp from? I'll measure my pan and intake/exhaust hoses from the cooler. Be good to know the temps as there is a lot of conjecture around this topic with very little other than a "mine has failed/not-failed" I'd find the data intersting--my guess is that it would be relevant to a break down in gear oil more than metallurgy... I'm on the fence as a lot of folks I respect don't use one...
The hottest part of an egine is the part furthest away from the radiator & oil cooler. In the case of the Rover V8 it would be cylinders # 7 & 8. In that area the hottest part is toward the top the the cylinder head meets the block so thats where you would measure. You can add around 20° to that reading depending on the ambient temp but more importantly because the head espetially being aluminum acts like a huge heat sink thereby disturbing the true oil temp reading.
Heat by a clear mile is the #1 enemy of an engine. When an engine is designed many specs are factored in with some being the correct heat range s plugs, radiator size and oil cooler size. The necessary parts go accomodate these specs are chosen from a parts bin or designed to accomodate them. Point being that engines are designed to operate ideally at a certain temp and reasonably well slightly below and above that.
Manufacturers dont provide unnecessary data such as oil temps without cooler and the CFM rating of the fan when the fan clutch is engaged or the fac service manual would be 3K pages long.
Personally I respect a lot of the members here and find their posts informative and enjoy reading them hence my post count since 06. There are a lot of misconceptions on this forum such as the oil cooler and oil pump priming procedure. At the expence of sounding sarcastic & you'll forgive me if I do is one to believe that LR would add a needless costly oil cooler if the engine didnt need it or techs are running around the factory with industrial size containers of lavender scented baby Vaseline to prime brand new 3.5 / 3.9 oil pumps or sticking a chop stick in cylinder # 1 to find TDC! I dont know where these misconceptions are rooted in but they seem to grow like wild fire on forums.
In several race applications techs will do away with the radiator fan for its hp robbing attributes but keep the oil cooler. My take on this is from what ive personally seen and experienced with oil coolers. Ive seen countless engines fail that dont have them and many that provided excellent longevity and more importantly running correctly with the ones that do or have upgraded oil coolers.
Hope this helps........