Question about initial start up on new rebuilt engine

[IX11rsr]

Is it mandatory to change the oil after 20 minutes of initial start up on a newly rebuilt engine ? PLS. I need this question answered.
TIA,
ra

[Don Settergren]

Change the oil and take a look at all the metal shaving floating around and you'll get an answer to your question. Also, your oil may have a lessened lubricating and cooling qualities with all the assembly lube and unburned petrol floating around. Cost shouldn't be an issue as regular fossel lubes are recommended over synthetics. And time... I can't imaging you put away your tools already, so it shouldn't take too long to change. Here's a toast to your completed rebuild and to lots and lots of driving miles!!

[Mike Juzenas]

Very cheap insurance. Make sure you replace you filter too...that is also cheap insurance. Dino oil is cheap so I would do it for the first 20 minutes, again after the first test drive, and then it starts to space out.

Cheers,

Mike