Thread: Blowby Article
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Old 19th July 2007
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dewjantim dewjantim is offline
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Originally Posted by aswracing View Post
Depends on how good the machine work is. If everything is perfect, it'll be seated when it's put together (it won't be though). If the bore and/or rings are out of round badly enough they may never seat.

The first run-ins are the most important. We like to start the motor and run it for about a minute, with fans blowing on it. Then let it cool ALL the way down. Repeat but the second time run it 2 minutes. Next time 3 minutes, etc. The idea is to let the rings do their job without overheating. They're very sensitive to localized overheating when only a little bit of them is touching the cylinder wall and you can damage the pistons easily.

Not if the rings are already seated.

You get the motor that hot before the rings are seated and you've probably already microwelded them. The thing with microwelding is that you may do it and never know it. It's primarily the top ring that does it, so you may not get any oil issues. It'll just be doomed to be a mediocre performer.

Not just no, but hell no!

Ron Dickey has an interesting case history of microwelding on his web site, it's worth a read:

Ron knows more about cylinders, pistons, and ring seal in his little finger than I'll ever know.
How do you break-in your race engines? Surely riding hundreds of miles on a race motor to break it in is out of the question? Dew.
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