Break in oil, new short block
 

I'm almost done replacing my small block. Do I need to use engine break-in oil? I'm in Indiana so it's pretty damn cold right now, so the prospect of using a heavier weight oil doesn't seem right. I know these engines have pretty tight clearances too.

My initial thought was to run break-in oil for the first 50-100 miles, change it out for 0w20, then change the oil again at 1k miles. All while following the manual's break-in procedure (under 4k, vary rpms).


Thoughts?


EDIT: I meant to post this in the Engine technical topic forum. Whoops.

Oh, I'd suggest you just put some 0w20 in it and run it for a few thousand miles, then change it.

:)

Unless you are extremely confident of your RTV application skills, I'd say dropping the oil pan to check for RTV debris is going to be more important than break-in oil, esp after a rebuild.

But to the original question, I used 0W-20 full synthetic. Changed oil within 1500 miles, and then again around 4000 miles, and then every 5500-6000 miles. Mobil 1 0W-20, sometimes 5W-30.

i changed my factory oil and filter at 1000km. All motorbikes do this, so I figured it was a good idea.

I broke it in properly "motoman" style. it works on every engine I've built or seen built.

when I changed it, I went with a quality synthetic 5w30. I'm not running 0 weight oil in a performance car. Nor will it ever be driven in cold weather.

IAG specifies break in oil for 1,500 miles to keep their warranty intact. 50, 500 changes then synthetic at 1,500