Break-in oil period

[ronw]

Getting close to starting my grandsons 340, the engine has been rebuilt and we got Royal Purple break-in oil for the start. My question is how long do you run the break-in oil after the initial start time? Do you run it on the street for a time or change it after the cam break-in? Thanks ron

 

[Darter6]

most things I have read is 500 miles

 

[roccodart440]

I dumped mine when it came off the dyno and filled it with synthetic.

Last one we did for my dad he ran that oil for the rest of the season.

 

[abodyjoe]

I changed it after cam break in. Then ran break in oil for a few hundred miles then went to a joe Gibbs oil.

 

[brian6pac]

20 minutes, change the oil & filter. After it cools off then another 30
minutes, change it again. A lot of people don't agree with me but you get a lot of metal on first break in of rings. It gets in to the lifters and galleys so the second change is just cheap insurance for me. Then change it after 500 miles tops or sooner it's up to you, and on how you drive it.