Oil pressure question...I promise it's not another "who likes what' thread!
This is a very good oil for the money. For the OP, with those clearances I wouldn’t be afraid to run a 50 grade oil.
Totally agree on the 50 with those clearances, as long as the pump pressure never tops out in the upper R’s.
Okay, aside from the 'funtime with screen names show' does anyone believe it's better to wait until more miles are on before going synthetic? I remember an old builder telling me 'not before 5000 miles' but that's been years..
And thanks fish but the relief spring only controls the ceiling, my issue is with the floor so-to-speak. I'm not getting into bypass with the 10-40, the 15-50 was actually bringing 5 more psi up top which, I don't think was opening the valve either. It *should* (there's that word again) be a 72-psi spring.
The way I look at it is idle pressure isn’t near as important as WOT pressure.
If your motor never hits the bypass it means you are getting the full flow of oil to the places where it counts.
Remember, flow volume is actually more important than pressure.
As far as synthetic goes, it’s great for newer motors with closer tolerances and thinner rings.
Overall it sounds like your motor is happy with what you are using.
Example:
I have a 96 Magnum all stock bottom end with roller cam, aftermarket heads and Hughes valve gear.
I run 10-30 full synthetic in the summer and 5-30 in the winter.
Cold idle with 10-30 is right at the relief spring pressure of 60lbs.
At temp (190-210) idle pressure is 35 lbs, and 55lbs at road speeds and rpm.
This tells me I am getting Near full pressure AND max volume for cooling of the parts When the motor needs it most.
Remember that thinner oil carries heat off and back to the pan faster.
Like I said, I think you are good right where you are.
