Lynn wrote:

The oil temp measured as close to the rear main oil gallery as possible
should be 210 or below. That is because the bearing overlay material is
loosing strength with higher temps. This is a rule developed based on
racing, (Racing Beat) where RPMs will be around 9,000 for 13Bs. Or 9,500 for
12As. Bearing stress is lower around 6,500 RPM. Still, it's not a bad idea to
Keep the oil well under 200 degrees. The engine builder reports power lost
Above 160 degrees on the oil temp. Water under 200 is OK. Power loss above 180,
But no damage.

 

Always a pleasure to hear your comments Lynn.   Thanks.

 

Rusty

 

Lynn's comments have been 'on the money'  with my own experiences.  BTW Rusty, at high throttle, my oil temps in the pan have run 35 - 40 degrees hotter than after the cooler so you might not have a problem at all.  It will be very interesting to see what your engine inlet oil temps are.  I love that dual water - oil cooler setup you have.  If there are enough square inches of transfer area, this is hard to beat.

 

Lynns previous comments about  bearing stress at our rpm range (~6000) should be considered when making decisions about oil pressure regulators & related items.  I think it is a waste of HP to run higher than stock oil pressure because of the lower bearing stress where we run.  I flew all the way to Oshkosh & back with only 35 - 37 psi when I had the blown front cover O-ring syndrome and the engine never suffered at all.  Main bearings showed no measurable wear 850 hours later.

 

Tracy