Break in for rebuilt motors?
 

Aside from the initial 20 min breakin on the hose, is there any other precautions to take...i.e. staying under a certain RPM range ro so many hours??:confused:

For the first ten hours try to vary speed every 10-15 minutes. No WOT for the first hour or so and then no more than short bursts for the next. Or you can run it like a race boat and go WFOT all day as soon as it hits the water:D And I try to change the oil after the first ten also.

I'm a firm believer in driving from day one the same way you are always going to drive it. I have done this with all my cars, boats, motorcycles and have never had engine issues.

Just avoid as much idling as humanly possible for the first couple hrs. And I change oil after 1 hr, then again at 10. Look at the oil and filter (inside) closely at 10 hrs.

Yup! i'm the same way...if its gonna break its gonna break.....babying it is not gonna help anymore now or 10hrs from now. :)

I all ways run mine 20 minutes at medium rpms just to ensure the rings are set, then it is full throttle.

If its going to go it will go then, it is only a matter of time we know it will eventually go.

"looks do matter!"

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I have to disagree with with the beat it from day one principle. Race engines are only made to last a much shorter time.

Use NON-synthetic multiweight oil. Change after the first run. Use Non-synthetic oil for 10-20 more hours. My engine builder said Syn. lubes too well and the rings don't seat properly.

Try not to idle much for the first 5-10 hours and resist the urge to make bursts. Vary RPM often.

When I had my engines Dyno'd, Performance Research did not want to do a "full HP test" unless I forced the issue. They said they were not broken in.

If you have your engines dyno'd you'll find the procedure to be a building one...start slow and work up varying RPM as you go.