I'm almost about to assemble my motor and my current bearings are ACL race for both rod and main. I thought I read somewhere that these are not good for the cold weather at all. I'm not really planning on driving the car during the cold winters but plan on starting it every week, letting it warm up, then shutting if off. And maybe even a little spirited driving if there isn't a lot of snow and salt on the road.

I'm wondering if these are safe enough to run in the winter. Coldest I've seen is -15F around here and it stays like that for a max of a week. Then goes back up to 20F. If not, what bearings would you guys recommend?

 

I've never heard of climate temperature affecting your choice on bearings. Doesn't make any sense. What matters is your clearances.

 

Bearing choice shouldn't matter, tolerances and weight of oil do. In your case climate extremely cold I would do prolly a 5w30 oil, as long as bearing tolerances are close to OEM you should have no issues.