What oil do you use for 350 Chevy break in?

Answer 1

I you are talking about a new car with a 350 engine, the basic break-in has already been done at the factory and your manual should tell you exactly how to proceed: type of oil, driving style, when to change oil/filter, etc.

If you are talking about a new crate engine or a freshly rebuilt 350 engine, and want to do it RIGHT, use a straight 30-weight oil. (not 10W-30 or anything with a "W" in the name.) Shell Rotella T is often recommended by long time engine builders.

Here's a good break-in procedure...

1. Fill engine w/ correct amount of 30 weight oil

2. Remove the distributor and use an oil priming tool and drill to bring oil pressure up to spec for (fully circulate oil through the engine)

3. Replace the distributor and set to standard SBC timing (appx is fine - just so it runs)

4. Fire the engine and bring it up to 2000rpm

5. Vary the engine speed from 2000-4000rpm for 20-30 minutes

6. CRITICAL: DO NOT LET THE ENGINE IDLE until break in is complete!!! (unless you have a roller cam then it doesn't matter much)

7. Shut down, drain oil, change filter, refill with same oil

8. Take care out on the road

9 Do medium accelerations from 10 up to 50mph then let it coast back down (don't downshift)

10. Repeat 5-10 times

11. Drive easy, keep it under 3000rpm for the first 500mi

12. Change oil and filter again

13. Keep it under 4000rpm for the next 1000mi

14. Change oil and filter again - using whatever brand/type you prefer