[daveid]

Hi,
I was just wondering what weight oil do you use in your big blocks?

[Bumpstick]

I`m located in the deep south so I normaly run 15-50wt Mobil 1...

[Sir Joab]

10-40w of whatever's cheapest.

[curtis73]

10-30 in socal. Perfect pressure; 20 psi at hot idle, bypass at 80, 45-55 psi on the highway. Stock bearing clearances on a 10/10 crank

[daveid]

i was running 20-50 and that seemed a little too thick so I went to 10-30 to try. IS that going to be too thin? right now its snowing but in the summer it get to about 90 degrees around here. The bearings I beleve are .10

[runn141]

i dont have a big block but i say use 10w40 all year.

[Double_v23]

10w-30 is my choice for daily use in the summer and slightly colder fall and spring. For break in I used Rotella SAE 30 if you have a flat tappet cam you may want to consider using an additive because BBC's are notoriously hard on cams because of the different angles of lifters, pushrods, valves, etc.

[11echo]

I've own big blocks continually from 1984, from Washington state to California in all types of weather and road conditions. I run 10-40wt oil in all of them! ...Still do.