<VV> Engine Operating Temps

[Smitty Smith]

Smitty Says:  Steve there is obviously going to be a correlation between head and oil.  When one goes up then the other goes up.  Not in any special ratio though.  In a well de flashed NA engine your numbers are about what I would expect in very high temps with the lower shrouds on.
   I believe keeping the shrouds on to prevent early engine wear is a subject that has more than one answer.  If you are going to jump in the car when it is 40 degrees out (or colder) and hammer the hell out of it, then it matters not if the shrouds are on or not.  You are going to hurt it.  If you get in the car when it is 100 degrees out and drive away at street speeds, you aren't hurting a thing.  I can almost guarantee a 20 degree oil temp drop by removing the shrouds.
   I take my shrouds off in the spring when it gets warm out and and put them back on when I think I might enjoy the heat.  I have built and run the life out of at least 3 130K mile engines and all have had shrouds done the same way.  People a lot smarter than me have found that terminal damage has been done to dino oil at 270 degrees.  At 260 you can just about expect normal oil change interval to be safe.  So your choice.  Worry about early failure of your engine because your oil takes a few minutes to come up to operating temp, or worry about the oil taking the bearings out because it was over heated for a few minutes.
One more opinion.  Stop worrying about some arbitrary number of oil temp warming up.  Think about what 150 degrees is like.  Think your pinkey could survive being immersed in that?  Your oil will be fine at that temp until you get out on the interstate.  

> From: Stephen Upham <contactsmu at sbcglobal.net>
> 
> Could someone tell me if there should be a correlation
> between the  
> head temps and oil temps or not.  I observed very high
> oil temps but  
> normal head temps.  The oil temp, measured with an
> adapted water temp  
> gauge with the sender just above the rim of the oil pan in
> the block  
> was reading 270 (gauge goes to 280).  Normally this
> reading was in  
> the 260's at the highest.  I measured the temps with a
> laser  
> temperature devise and the oil cooler was at 200-205 and
> the oil pan  
> was 240.  The dual CHT never got above 250 and was
> steady throughout  
> the time that this was happening.  This has been a
> pretty normal  
> reading since they were installed when the engine was
> rebuilt two  
> years ago.  I'm also wondering if the oil in the car
> has been  
> stressed and should be replaced.  I'm using Brad Penn
> racing oil (the  
> green oil) and it has only been about 250 miles since the
> last oil  
> change.  I have been using this as the break-in oil
> before switching  
> to synthetic.  I WILL be dropping the shrouds.  I
> had kept them on  
> because it was taking forever to get the engine to 220 in
> order to  
> prevent acid in the oil.  I now prefer to drive for a
> long time at  
> each outing than drive for a few miles and replace an
> engine.  I  
> recently bought a gauge that I can install in the port of
> the Clark's  
> ultimate oil pan that is on the car.  I hope to do
> this with the  
> other gauge still installed for a while to compare temps
> and see how  
> it compares.
>