<snip>

, but the real good news is the length of time it took to heat up the oil.  The only diff between today, and yesterday is the oil weight.  Today, it took more than twice as long to get the oil up to 140.  I was even running higher rpms to get it there.  Even after some full throttle running, I still never saw 200 degrees.  This may be the key to my oil temp issues.  

Ah-h-h; something doesn’t compute here, at least not for me.  Did you start from the same temp?  Was the air a lot cooler?  More air blowing through the cooler? More oil in the pan?  A slight reduction in viscosity can’t account for the difference.  The flow rate will be essentially the same, as I think your pressure drops confirm; so-o-o-o what makes the heat rejection rate double?

But it does bring up the question, what is the recommended oil viscosity?  5W30 seems a bit low.

Al